Vascular access guideline recommendations stipulate that an upper arm cephalic AVF, arising from the brachial or radial artery in the case of high brachial artery bifurcation, must be co
Trang 2Diagnostic and Interventional Radiology
of Arteriovenous Accesses for Hemodialysis
Trang 4Luc Turmel-Rodrigues • Claude J Renaud
Diagnostic and Interventional Radiology of Arteriovenous
With contributions by Bernard Beyssen, Jean-Jacques
Godier, Albert Mouton, Josette Pengloan, and Richard Shoenfeld
Trang 5Translation from the French language edition ‘Radiologie diagnostique et interventionnelle des accès artério-veineux pour hémodialyse’ by Luc Turmel, © Springer-Verlag France, Paris, 2012; ISBN: 978-2-8178-0265-7
DOI 10.1007/978-2-8178-0366-1
Springer Paris Heidelberg New York Dordrecht London
Library of Congress Control Number: 2012951701
© Springer-Verlag France 2013
This work is subject to copyright All rights are reserved by the Publisher, whether the whole or part of the material is concerned, speci fi cally the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on micro fi lms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied speci fi cally for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher’s location, in its current version, and permission for use must always be obtained from Springer Permissions for use may be obtained through RightsLink at the Copyright Clearance Center Violations are liable to prosecution under the respective Copyright Law
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Trang 6Contents
Strengths and Weaknesses 1
References 4
2 Role of the Nephrologist, Interventional Radiologist, and Vascular Access in the Treatment of End-Stage Renal Disease 5
References 9
3 Access Creation Strategy 11
References 14
4 Natural History of Vascular Access 15
References 17
5 Radiological Anatomy and Preoperative Imaging of Upper Limb Vessels 19
5.1 Arterial Anatomy 19
5.2 Venous Anatomy 22
5.3 Preoperative Radiological Imaging 28
5.3.1 Indications 28
5.3.2 Techniques of Venography 29
5.3.3 Interpretation of Venograms 32
5.3.4 What Use Is Venous Mapping to Surgeons? 34
6 Indications and Imaging Modalities in Dialysis Access 35
6.1 Indications 35
6.2 Clinical Abnormalities 35
6.3 Thrombosis Prevention 36
6.4 Which Type of Image Modality? 36
References 38
Trang 7vi Contents
7 Psychological and Clinical Issues 39
7.1 Psychology of Patients Referred for Intervention 39
7.2 Clinical Presentations of Patients and Dialysis Accesses 40
7.2.1 Patients 40
7.2.2 The Hand 40
7.2.3 The Normal Vascular Access 41
7.2.4 The Flat Fistula 41
7.2.5 The Hyperpulsatile Fistula 42
7.2.6 The Falsely Normal Fistula 43
7.2.7 The Inappropriately Needled Fistula 43
7.2.8 Hyper Flow 43
7.2.9 Arm and/or Facial Edema 43
7.2.10 Collateral Veins 44
7.2.11 Cutaneous Necrosis 45
7.2.12 Aneurysms 46
7.2.13 The Painful Vascular Access 47
8 Patient Preparation Prior to Angiography and Endovascular Interventions 49
8.1 Background 49
8.2 Essential Patient Data 49
8.3 Sedation 50
8.4 Allergies 50
8.5 Anticoagulation 51
8.6 Acute Access Thrombosis 51
9 Angiography (Fistulography) 53
9.1 Role of Angiography 53
9.2 Angiography Suite 54
9.3 Contrast Agents 54
9.4 Angiography Techniques 55
9.4.1 Background 55
9.4.2 Low Flow Forearm AVFs 55
9.4.3 Low Flow Upper Arm AVF 56
9.4.4 Venous Hypertension 56
9.4.5 Distal Ischemia 57
9.4.6 Hyper Flow AVFs 57
9.4.7 Prosthetic Grafts 57
9.4.8 Entrapment 57
9.5 Interpretation of Angiograms 58
9.5.1 Background 58
9.5.2 Arteries 58
9.5.3 The Veins 59
Trang 8vii Contents
9.6 Sites of Stenoses 61
9.7 Rarities 62
9.8 Postoperative Imaging 63
References 63
10 Dilation and Stent Placement 65
10.1 Dilation (or Percutaneous Transluminal Angioplasty) 65
10.1.1 Reading Angiograms 65
10.1.2 Contraindications to Dilation 66
10.1.3 Indications for Dilation 67
10.1.4 Basic Techniques of Angioplasty 70
10.1.5 Technical Details 86
10.1.6 Dilation of Stenosis Based on Anatomical Location and Access Type 92
10.2 Stents 122
10.2.1 Description 122
10.2.2 Deployment 123
10.2.3 Potential Drawbacks 123
10.2.4 Indications 124
10.3 Restenosis 127
10.4 Which Strategy: To Redilate or Give Up? 128
References 128
11 Hand Ischemia 131
11.1 Background 131
11.2 An Atypical Form of Acute Ischemia: Ischemic Monomelic Neuropathy (IMN) 136
11.3 Chronic Ischemia 136
11.3.1 Diagnosis 136
11.3.2 Noninvasive Work-Up 137
11.4 Arteriography 139
11.4.1 Technique 139
11.4.2 Principles of Reading Arteriograms 142
11.4.3 Interpretation of Arteriograms and Concomitant Treatment 142
11.5 Surgical Treatment 148
11.5.1 Indications and Principles of Surgical Treatment 148
11.5.2 Upper Arm Hyper Flow AVFs 149
11.5.3 Hyper Flow Forearm AVFs 150
11.5.4 Normal Flow Upper Arm Accesses 150
11.5.5 Normal Flow Forearm AVFs 151
11.6 Conclusion 153
References 153
Trang 9viii Contents
12 Treatment of Thrombosed Accesses 155
12.1 Introduction 155
12.2 History 155
12.3 The Clinical Problem 157
12.4 Contraindications to Percutaneous Thrombectomy 158
12.4.1 Temporary Contraindications 158
12.4.2 Absolute Contraindications 158
12.4.3 Relative Contraindications 159
12.5 Patient Preparation 160
12.6 Percutaneous Thrombectomy by Thromboaspiration: Basic Technique 161
12.6.1 General Principles 161
12.6.2 “Venous” Access 162
12.6.3 “Arterial” Access 169
12.6.4 Venous Outflow Thromboaspiration 172
12.6.5 Arterial Inflow Thromboaspiration 173
12.6.6 Arterial Plug 174
12.6.7 Dilation 175
12.6.8 Arterial Embolism 176
12.6.9 Completion Angiography and Device Removal 178
12.7 Special Considerations and Challenges 178
12.7.1 The Non-flowing but Non-thrombosed AVF 178
12.7.2 Working with a Single Introducer-Sheath 180
12.7.3 Segmental Thromboses 181
12.7.4 Isolated Painful Thrombosed Aneurysms 182
12.7.5 Difficult Venous Access 182
12.7.6 Failure to Cross the Venous Outlet 182
12.7.7 Central Vein Occlusions 183
12.7.8 Risks Associated with Intervening on Brachial accesses 183
12.7.9 Failure to Cross the Arteriovenous Anastomosis 185
12.7.10 Proximal Artery Thrombosis 185
12.7.11 Distal Radial Artery Thrombosis 187
12.7.12 Aneurysms 187
12.7.13 Old AVFs 190
12.7.14 Looped Grafts 192
12.7.15 Lower Limb Accesses 192
12.7.16 Kinks and Traps 192
12.7.17 Cluttering 192
12.7.18 Alternative Thrombectomy Techniques 193
12.7.19 Early Rethrombosis 193
Trang 10ix Contents
References 194
13 Therapeutic Occlusion of Dysfunctional Accesses 197
Reference 197
14 Complications During and After Vascular Access Endovascular Procedures 199
15 Vascular Access Intervention Outcomes 203
References 204
Appendices 207
The Anesthetist and Vascular Access Endovascular Procedures 207
Treatment of Hyperkalemia in End-Stage Kidney Disease Patients During Vascular Access Procedures 209
Introduction 209
Definition, Causes, and Risk Stratification of Hyperkalemia 209
Treatment 210
Conclusion 211
References 212
Basic Tools Required to Perform Endovascular Dilation, Stenting, and Thrombectomy Procedures 213
A Typical Request Form Template for Vascular Access Endovascular Procedure 215
Trang 12Abbreviations
AVF(s) ArterioVenous Fistula(s)
CAS Cephalic Arch Stenosis
CN Contrast Nephropathy
CT(A) Computed Tomography (Angiography)
DBI Digital-Brachial Index
DHIS Distal Hypoperfusion Ischemic Syndrome
DRAL Distal Radial Artery Ligation
DRIL Distal Revascularization Interval Ligation
ESRD End-Stage Renal Disease
IMN Ischemic Monomelic Neuropathy
MR(A) Magnetic Resonance (Angiography)
PAI Proximalization of Arterial In fl ow
PAVA Proximalization of the ArterioVenous Anastomosis
PFO Permanent Foramen Ovale
PRAL Proximal Radial Artery Ligation
PTA Percutaneous Transluminal Angioplasty
PTFE PolyTetraFluoroEthylene
RBP Rated Burst Pressure
RRF Residual Renal Function
RRT Renal Replacement Therapy
RUDI Revision Using Distal In fl ow
UHP Ultra High Pressure
Trang 13L Turmel-Rodrigues, C.J Renaud, Diagnostic and Interventional Radiology
of Arteriovenous Accesses for Hemodialysis, DOI 10.1007/978-2-8178-0366-1_1,
© Springer-Verlag France 2013
Since their advent in the 1980s, endovascular interventions (percutaneous transluminal angioplasty and mechanical declotting) have gradually and fundamentally revolu-tionized the multidisciplinary management of dialysis vascular access One of the key triumphs of this arm of interventional radiology was the successful treatment of cen-tral vein stenoses in a minimally invasive and less labor-intensive manner which previously required complex and often imaginative surgical bypass procedures [ 1– 3 ] Although initial publications on the pioneering work from US and European centers reported modest results, endovascular interventions continued to gain greater acceptance based on the idea that, when compared with surgery, they were a lesser evil and that reintervention was possible and generally accepted (Fig 1.1 ) The introduction of Wallstent™ in 1987 resulted in signi fi cantly improved short-term outcomes Unfortunately, overutilization of stents generated a new set of problems, namely, compromise of venous capital available for future access creation [ 4, 5 ] The relative success of endovascular dilation seemed to conjure its omnipotence
as a universal panacea for all stenotic lesions in the vascular access circuit, leaving little role for alternative approaches like surgery It is however well-known that certain lesions such as juxta-anastomotic stenoses in forearm autogenous arterio-venous fi stulas (AVFs) respond better to surgical revision than to endovascular treatment [ 6 ] Despite restenosis, rethrombosis, modest patency rates, and need for reintervention, nephrologists and patients alike have come to accept endovascular
Chapter 1
Endovascular Repair of Dialysis Fistulas
and Grafts: Strengths and Weaknesses
Luc Turmel-Rodrigues and Claude J Renaud
L Turmel-Rodrigues , M.D ( * )
Department of Vascular Radiology , Clinique St-Gatien ,
8 place de la cathédrale , 37000 Tours , France
Department of Vascular Radiology , Clinique Ambroise Paré ,
25 boulevard Victor Hugo , 92200 Neuilly-sur-Seine , France
e-mail: luc.turmel@wanadoo.fr
C J Renaud , M.D
Department of Medicine , Khoo Teck Puat Hospital, Alexandra Health ,
90 Yishun Central , Singapore 768828 , Singapore
e-mail: renaudcj@hotmail.com
Trang 142 1 Endovascular Repair of Dialysis Fistulas
interventions as the standard of care, mostly as result of their minimal invasiveness and ease of being performed in an ambulatory setting with little recourse to general anesthesia On the other hand, an end-stage access requiring frequent endovascular reintervention should include a multidisciplinary strategy for creation of new vascu-lar access, less prone to repeated failures
Initially the sole preserve of interventional radiologists, endovascular access interventions have come a long way and are now also performed by a new generation
of vascular surgeons and nephrologists, particularly in centers lacking a strong and committed radiology-led interventional vascular access service The training, accred-itation, maintenance of competency, and skills of these new players pose a number
of challenges, including turf battles, lack of common de fi nitions, and reporting dards The general consensus, nonetheless, is that these challenges can only be resolved through multidisciplinary collaboration and more formalized training
As the pioneer interventional radiologists became more experienced in more challenging accesses and patients (e.g., in elderly, diabetics, and obese), they ventured into unchartered territories by addressing hitherto untreatable lesions In
Fig 1.1 This patient was eventually dialyzed on
a right brachial–basilic fi stula The multiple scars
on her forearm were a result of several attempts
at creation and revision of antecedent accesses
by open surgery They are lingering testament of
the strong points of pursuing treatment of dialysis
access complications by endovascular means
Trang 151 Endovascular Repair of Dialysis Fistulas
the 1990s, they began treating nonmaturating fi stulas followed some years later by dilation of long in fl ow radial artery stenoses [ 7, 8 ]
A major breakthrough in the late 1980s was the percutaneous declotting of bosed vascular accesses with relatively greater ease and success using mechanical techniques Although earlier published attempts in 1985 reported disappointing results [ 9, 10 ] , this innovative approach became timely in the wake of a rising dependence on prosthetic polytetra fl uoroethylene (PTFE) grafts (Gore-Tex ® ) with their associated high thrombosis rates Quick restoration of graft patency by interventional radiolo-gists reduced dependence on temporary dialysis catheters Declotting was subsequently adapted to thrombosed AVFs as evidenced by the fi rst publications in 2000, which reported that over 90 % of thrombosed AVFs could be salvaged by endovascular means [ 11 ] Prior to that, the majority of thrombosed AVFs were generally deemed unsalvageable Unfortunately, the abandonment of thrombosed AVFs is still the rule
throm-in many centers lackthrom-ing the expertise and tools to carry out endovascular declottthrom-ing Endovascular treatment of vascular access complications nonetheless shares the same challenges and shortfalls as the surgical approach Many cases have unique complexities Success is greatly dependent on the skill and experience of the opera-tor, usually acquired at the expense of a steep learning curve Therefore, it is not an activity to be done on a part-time basis or with a sense of detachment or lack of commitment, all of which may limit one’s ability to remain up to date
Ready access to good quality angiography equipment, safe working ment, and an appropriate inventory of often expensive consumables (catheters, guidewires, balloons, and stents) are indispensable and can be the make-or-break factor in establishing a successful program
environ-Additional skills in implanting, exchanging, troubleshooting, and explanting chronic tunneled catheters may be required Overall skill-sets vary from one center to another For example, in France, nephrologists insert catheters and radiologists han-dle most of the endovascular issues, while in the USA, nephrologists and radiologists
do both [ 12 ] Intuitively, an interventionist skilled in both is most desirable when, for example, it is necessary to dilate a central vein stenosis to allow catheter placement
In summary, the strength of the endovascular approach resides on the fact that it
is a minimally invasive option, which can be performed many times on the same vascular access It can restore patency of accesses otherwise deemed unsalvageable, saving the need for a more invasive surgical approach or abandonment and resort to
a central catheter
Its weakness is its cost and signi fi cant restenosis rate despite high immediate success There is indeed a higher tendency for inadequately trained operators to promote substandard practice and abuse which stem from fi nancial opportunism, lack of multidisciplinary consultation, and collegiality Examples include angio-plasty of stable mild to moderate or nonexistent stenoses, placement of stents which compromise venous capital, or repeated dilations of end-stage access when the patient can clearly bene fi t from the creation of a new vascular access
We shall speak of interventional radiologists in this book, while being cognizant
of the fact that nowadays other interventionists (surgeons, nephrologists, and ologists) share some of the work pioneered by radiologists
Trang 16cardi-4 1 Endovascular Repair of Dialysis Fistulas
5 Turmel-Rodrigues L, Bourquelot P, Raynaud A, Sapoval M (2000) Primary stent placement in hemodialysis-related central venous stenoses: the dangers of a potential “Radiologic dictator- ship” Radiology 217:600–602
6 Long B, Brichart N, Lermusiaux P (2011) Perianastomotic stenosis of direct wrist autogenous radial-cephalic arteriovenous accesses for dialysis: transluminal angioplasty or surgery? J Vasc Surg 53:108–114
7 Turmel-Rodrigues L, Mouton A, Birmelé B et al (2001) Salvage of immature forearm fi stulas for haemodialysis by interventional radiology Nephrol Dial Transplant 16:2365–2371
8 Turmel-Rodrigues L, Boutin J, Camiade C (2009) Percutaneous dilation of the radial artery in nonmaturing autogenous radial-cephalic fi stulas for haemodialysis Nephrol Dial Transplant 24:3782–3788
9 Zeit R, Cope C (1985) Failed hemodialysis shunts: one year of experience with aggressive treatment Radiology 154:353–356
10 Bookstein J, Fellmeth B, Roberts A (1989) Pulsed-spray pharmacomechanical thrombolysis: preliminary results Am J Roentgenol 152:1097–1100
11 Turmel-Rodrigues L, Pengloan J, Rodrigue H et al (2000) Treatment of failed native venous fi stulae for hemodialysis by interventional radiology Kidney Int 57:1124–1140
12 Trerotola S (2000) Hemodialysis catheter placement and management Radiology 215: 651–658
Trang 17L Turmel-Rodrigues, C.J Renaud, Diagnostic and Interventional Radiology
of Arteriovenous Accesses for Hemodialysis, DOI 10.1007/978-2-8178-0366-1_2,
© Springer-Verlag France 2013
Hemodialysis, peritoneal dialysis, and renal transplantation are the three modalities
of renal replacement therapy (RRT) in end-stage renal disease (ESRD) A young ESRD patient is likely to experience at least 2 RRT modalities in a lifetime Ideally, hemodialysis depends on the timely and successful creation of a vascular access (AVF or prosthetic graft) or on insertion of a central catheter in cases requir-ing urgent unplanned dialysis
Central catheters may either be temporary (non-tunneled) or chronic (tunneled) Temporary catheters are commonly required for acute dialysis in patients without
a functional AVF or graft Chronic tunneled catheters may be placed acutely or semi-electively in anticipation of vascular access creation or maturation, which can take weeks to months to realize Tunneled catheters are also increasingly being used
in patients with multiple comorbidities and short life expectancy Indeed, the ation of a vascular access may be compromised in the presence of severe heart failure, arteriopathy, bankruptcy of venous capital due to multiple venipunctures, or exhaustion of anatomic sites from multiple previous vascular access failures In this instance, a catheter is certainly a viable and safer alternative to creating an exotic or
Chapter 2
Role of the Nephrologist, Interventional
Radiologist, and Vascular Access in the
Treatment of End-Stage Renal Disease
Luc Turmel-Rodrigues , Josette Pengloan , and Claude J Renaud
L Turmel-Rodrigues , M.D ( * )
Department of Vascular Radiology , Clinique St-Gatien ,
8 place de la cathédrale , 37000 Tours , France
Department of Vascular Radiology , Clinique Ambroise Paré ,
25 boulevard Victor Hugo , Neuilly-sur-Seine 92200 , France
Department of Medicine , Khoo Teck Puat Hospital, Alexandra Health ,
90 Yishun Central , Singapore 768828 , Singapore
e-mail: renaudcj@hotmail.com
Trang 186 2 Role of the Nephrologist, Interventional Radiologist
end-stage vascular access such as axillo-popliteal or femoral artery–right atrium bypass graft, to name a few
Although favorable outcomes have incidentally been reported with use of neled catheters, AVFs remain the most desirable vascular access due to their superior long-term patency and lower complication rates This has formed the basis for clini-cal practice guidelines advocating a distal AVF as the fi rst access for all ESRD patients initiating dialysis
Nephrologists, usually the custodians of pre- and peri-dialysis care, are in a ileged position to spearhead the selection and timing of access creation, monitoring, and timely intervention for dysfunction They must be able to fi nely balance and integrate the competing demands for more thorough and cost-effective best prac-tices that culminate in durable solutions to vascular access problems This of course requires the establishment of a network of readily available key personnel from other relevant disciplines Unfortunately, such multidisciplinary collaboration is not always practical in many institutions since dialysis patients are often placed low on the priority list Unfortunately, in such situations, training of dedicated vascular access personnel may be compromised
When it comes to the creation, monitoring, and maintenance of accesses, the nephrologist plays the role of the orchestral conductor who must use diplomatic and professional fi nesse to justify and obtain patients’ transfer to neighboring regional
or national centers particularly when the local institution lacks expertise in vascular access management but ironically excels in other areas
It is therefore not surprising that in a number of such instances, nephrologists have had to take over the creation of AVFs (Italy, Slovenia, some cities in France, Germany, India) and endovascular dilation and declotting (USA, Japan, Portugal,
Singapore) in addition to performing Doppler sonographic examinations Failure to
act concertedly in a discordant milieu results in a high rate of complications/failures and increasing tunneled catheter dependency with its attendant mechanical and infectious complications
Distal AVFs are more likely to be created where there exist functional and interactive multidisciplinary teams consisting of nephrologists, vascular ultra-sonographers, dedicated surgeons, and interventional radiologists The products
of a discordant or nonexistent team are often a high number of upper arm AVFs, followed by a high reliance on prosthetic grafts and lower limb accesses and ulti-mately resulting in a disastrously high proportion of tunneled catheters
The nephrologist as the vascular access conductor also plays a pivotal role in the preservation of venous capital prior to AVF creation, that is, in the early stage of chronic kidney disease, when forearm veins must be spared from inadvertent or deliberate venipuncture The aim is to maximize venous capital to enable the cre-ation of a successful and lasting distal AVF
A robust and aggressive forearm fi stula fi rst strategy has a number of advantages, namely, lower access fl ow rates which exert less stress on the heart and are less likely to induce distal ischemia, higher cumulative patency rates, and better preser-vation of upper veins for future AVFs Moreover, most interventional radiologists agree that endovascular interventions on distal AVFs are less painful (veins and arteries are more super fi cial, making it easier to administer local anesthesia) and less risky: lower risk of distal arterial embolization during declotting and lower
Trang 192 Role of the Nephrologist, Interventional Radiologist
likelihood of placing stents in the venous out fl ow or central veins, which often tively impact on the creation of future alternative ipsilateral vascular accesses However, such a strategy entails coaxing vascular surgeons into creating radial–cephalic or even ulnar–basilic AVFs when the forearm veins and arteries are of suboptimal quality The downside to this is a higher technical failure and nonmatu-ration rate Nonmaturation is nonetheless easily manageable as a result of vigorous monitoring and early detection by nephrologists and prompt endovascular or surgi-cal revision by the second postoperative month A number of those nonmaturing AVFs that do require primary dilation are subject to repeated interventions in the
fi rst year, but redilations become less frequent thereafter
Nephrologists have the unenviable task of educating patients and family bers alike so that nonmaturation is not seen as a surgical mistake and dilations and redilations are not considered the result of a bad job performance by the radiologist
mem-It was indeed the elevated incidence of high- fl ow rates and distal ischemia seen with upper arm AVFs in the 1980s and 1990s that prompted a forearm fi stula fi rst para-digm shift in a number of European centers and more recently in the USA This was certainly aided by innovations in microsurgery and interventional radiology The high rate of thrombotic and infective complications associated with prosthetic grafts makes them a vascular access option of last resort in the upper limb However, the repeated dilations sometimes required within the fi rst year of AVF creation to achieve maturation make the autogenous fi stula fi rst approach quite a challenging proposition in the elderly and in patients with high comorbidity scores Some would argue that under such circumstances, a tunneled catheter would be more desirable
as long as the center-speci fi c catheter-related infection rate remains low
A sound vascular access creation strategy is of fundamental importance but remains a subject of great controversy and dispute Vascular access monitoring by nephrologists and allied personnel is no less controversial To roughly summarize, there are two schools of thoughts: the “preventionists” who are those who would go
to any length to save a vascular access from thrombosis and the “fatalists” who take little interest in vascular access until an acute thrombosis intervenes The “preven-tionists” argue that acute thrombosis is stressful and compromising to patients’ quality of life, notwithstanding its other sequelae It is disruptive to the dialysis team and patients alike, while monitoring and preventive dilation of stenoses allow better access and patient survival The “fatalists” on other hand counterargue that dilations predicated on the sole objective of preventing access thrombosis are an unnecessary discomfort to patients when little evidence exists that they do prolong patient survival or modify cumulative access patency Each school of thought has its own published outcome data to back its assertions [ 1– 4 ]
European, American, and other best clinical practice guidelines do recommend routine vascular access surveillance and monitoring and preventive dilation of stenoses to prevent thrombosis The recommendations are often based on the results
of clinical trials with questionable research methodology Unfortunately, ing based on physical examination of accesses to detect low fl ow, hyperpulsatility, skin lesions, or abnormal thrills is very operator-dependent Dialysis nurses are in a better position to take ownership of vascular access issues given that they have ample opportunity to examine accesses three times a week prior to cannulation There is a general lack of emphasis on training, not to mention expertise in physical
Trang 20monitor-8 2 Role of the Nephrologist, Interventional Radiologist
examination among both dialysis nurses and nephrologists The concept of vascular access coordinators, who are specially trained nurses, has recently been adopted in
a number of countries (USA, UK, Canada, and Australia) This concept might not always be applicable in every clinical setting
The lack of skills in physical examination as well as interobserver variability have prompted a search for other more objective surveillance and monitoring modalities Dynamic venous pressure monitoring has serious limitations, while to a certain extent, serial access fl ow monitoring has allowed nurses to take some owner-ship of vascular access monitoring The link between degree of stenosis, access
fl ow, and risk of thrombosis is well-known but is controversial and not consistently supported by evidence Access fl ow can be measured by duplex ultrasonography but requires referral to a vascular lab, angiologist, or radiologist It can also be per-formed at the bedside during dialysis by a number of relatively cheaper and more practical methods: Transonic ® , Critline ® , or ionic dialysance
Access fl ow monitoring should be performed monthly and more or less often in at-risk or problem-free vascular accesses, respectively, with the same apparatus Based on guideline recommendations, access fl ows of 600 mL/min or less in pros-thetic grafts and 500 mL/min or less in AVFs indicate an increased risk of access thrombosis and should trigger a search for stenosis and its correction if found These are not hard and fast rules Serial fl ow measurements in grafts are less sensi-tive and frequently do not indicate the best time to intervene on a critical stenosis, whereas in AVFs coupling fl ow measurement with physical examination allows for more accurate detection of critical stenosis and timely intervention, thus avoiding unnecessary dilation of “stenoses” that would have been picked up by physical examination alone Trending of serial access fl ows and gradient drops in fl ow are equally important For instance, a fl ow of 500 mL/min or less may be normal in a radial–cephalic AVF with a small caliber radial artery in a diabetic, smoker, or an elderly patient
Unfortunately, access fl ow monitoring other than by duplex ultrasonography is discouraged and disincentivized in some countries due to the lack of reimbursement
It is our unsettling observation and assertion that the rate of access thrombosis is center-speci fi c and correlates well with the degree of commitment of attending neph-rologists to proper access examination and whether experienced vascular sonogra-phers are available locally Hence, both vascular access thrombosis rate and survival are performance indicators of the quality of vascular access care In many centers, thrombosed accesses fall prey to the unholy triad of abandonment–tunneled catheter–new access creation It is well-known that such an approach leads to early exhaustion
of vascular access options and ultimately impacts negatively on patients’ survival Numerous challenges and controversies persist For instance, what is the best approach for a patient whose access requires dilation every 3 months to maintain patency? Are repeated dilations acceptable practice? Should this patient have a new vascular access created? What is the optimal acceptable access fl ow? Should we accept an access fl ow that is greater than 20 % of the cardiac output? Should we have de fi nitive fl ow reducing procedures for hyper fl ow fi stulas knowing that these techniques are not so straightforward and that the patency of these accesses may be
Trang 212 Role of the Nephrologist, Interventional Radiologist
at risk? Should we continue to create vascular accesses in the elderly above 80 years old knowing the impact of access fl ow on cardiac function?
Of course, each patient should be assessed on a case-by-case basis Depending
on the patient’s age, comorbidities, attitude, belief, and surrounding environment, a menu of customized solutions should be proposed while respecting the fundamental principles, which are timely creation of an AVF as distal as possible with the lowest access fl ow suitable for the dialysis needs
Although we have come a long way in terms of multidisciplinary collaboration, there is still a lot of work to be done on vascular access for hemodialysis The best strategy is not always easy to de fi ne
References
1 Lumsden A, MacDonald M, Kikeri D et al (1997) Prophylactic balloon angioplasty fails to prolong patency of expanded polytetra fl uoroethylene arteriovenous grafts: results of a prospec- tive randomized study J Vasc Surg 26:382–392
2 McCarley P, Wingard RL, Shyr Y et al (2001) Vascular access blood fl ow monitoring reduces access morbidity and costs Kidney Int 60:1164–1172
3 Tessitore N, Mansucto G, Bedogna V et al (2003) A prospective controlled trial on effect of percutaneous transluminal angioplasty on functioning arteriovenous fi stulae survival J Am Soc Nephrol 14:1623–1627
4 Shahin H, Reddy G, Sharafuddin M et al (2005) Monthly access fl ow monitoring with increased prophylactic angioplasty did not improve fi stula patency Kidney Int 68:2352–2361
Trang 22L Turmel-Rodrigues, C.J Renaud, Diagnostic and Interventional Radiology
of Arteriovenous Accesses for Hemodialysis, DOI 10.1007/978-2-8178-0366-1_3,
© Springer-Verlag France 2013
Nowadays, a multidisciplinary vascular access team has at its disposal a number of clinical practice guidelines and recommendations from several international societ-ies on the best strategy to adopt when planning an access for a particular end-stage renal disease (ESRD) patient [ 1– 5 ] However, not all medical insurance companies
or state agencies pay attention to or police their implementation Several of these recommendations are consensus and opinion-based rather than derived from rigor-ous level 1 and 2 evidences All of them ignore the autogenous ulnar–basilic fi stula
at the wrist and the techniques of arterialized vein super fi cialization in the forearm (lipectomy, transposition, and elevation) The way they are adopted is selective at best and depends largely on the implications they have on the personal preferences
of each member of the multidisciplinary team, that is, nephrologist, surgeon, and interventional radiologist For instance, a concerned and well-versed nephrologist might insist on more forearm AVFs, while a surgeon working outside a multidisci-plinary team structure might be more personally inclined on creating upper arm AVFs and placing too many grafts
Chapter 3
Access Creation Strategy
Luc Turmel-Rodrigues, Albert Mouton , and Claude J Renaud
L Turmel-Rodrigues , M.D ( * )
Department of Vascular Radiology , Clinique St-Gatien ,
8 place de la cathédrale , 37000 Tours , France
Department of Vascular Radiology , Clinique Ambroise Paré ,
25 boulevard Victor Hugo , 92200 Neuilly-sur-Seine , France
e-mail: luc.turmel@wanadoo.fr
A Mouton , M.D
Department of Dialysis Access Surgery , Clinique de l’Archette ,
83 rue Jacques Monod , 45160 Olivet , France
e-mail: mouton@noos.fr
C J Renaud , M.D
Department of Medicine , Khoo Teck Puat Hospital, Alexandra Health ,
90 Yishun Central , Singapore 768828 , Singapore
e-mail: renaudcj@hotmail.com
Trang 2312 3 Access Creation Strategy
Similarly, the lack of a vascular interventional radiology service or any other form of endovascular expertise can lead to the rapid depletion of available options for AVFs, especially in the forearm
A great deal is known about and advocated on venous capital preservation Venous capital is adversely affected by venipunctures and venous perfusions often performed on patients with multiple comorbidities and hospital admissions Hence, the type and location of AVF created depend a lot on how well veins have been looked after during the pre-ESRD phase Venous preservation becomes even more important in ESRD patients with expected prolonged survival
Every time a vascular access is created or revised, thinking and planning should focus on the possibilities for future access creation once the current one fails The approach therefore should be to create forearm AVFs and avoid any procedure that may compromise the venous out fl ow (e.g., insertion of a subclavian catheter during
a critical illness, a peripherally inserted central catheter for chemotherapy or a pacemaker)
Arterial capital is less talked about but can be compromised during arteriography that is increasingly being performed in the form of transradial coronary angiogra-phy Thrombosis of the radial artery, which occurs in 2–4 % of cases, remains asymptomatic until the creation of a radial–cephalic AVF is envisaged A throm-bosed radial artery not only denies the ESRD patient a distal AVF but also increases the risk of distal ischemia once an AVF is created above the elbow Vascular access guidelines recommend against transradial arteriography in patients with chronic kidney disease However, interventionists performing coronary angiography often ignore this We have seen at least three such cases in our own practice where an ipsilateral vascular access could not be created
The type and location of the vascular access depend on the results of the erative physical examination, ultrasound, or angiographic (either contrast or carbon dioxide) venous mapping and the patient’s age, general condition, and expected date
preop-of dialysis initiation A smooth line preop-of communication between the referring rologist and surgeon is therefore indispensable for these factors to be considered The radial–cephalic AVF has been championed as the vascular access of fi rst choice However, surgeons not well versed in vascular access surgery can be too demanding as to the size and caliber of forearm veins and arteries with the result that fewer of this type of access are created as opposed to upper arm AVFs Small vessel caliber results in more challenging anastomosis creation, especially when surgeons lack the skills in microsurgical techniques and thus risk of technical failure looms high
A mature AVF is usually de fi ned as one in which the arterialized vein can be cannulated successfully with two needles and satis fi es prescribed dialysis blood
fl ow for at least three dialysis sessions Most radial–cephalic AVFs mature by the second postoperative month Those that do not mature are often considered a surgi-cal failure in older and some more recent vascular access literature because surgical techniques of access super fi cialization and interventional radiology are not always considered as salvage interventions Indeed, super fi cialization techniques, such as lipectomy, transposition-tunneling, and elevation, guarantee that the majority of
Trang 243 Access Creation Strategy
AVFs can be created in the forearm in obese patients In addition, the presence of a skilled interventional radiologist in the multidisciplinary team ensures the salvage
of most nonmaturing fi stulas
Patient’s hand dominance is not an absolute overriding factor in vascular access planning In most cases, a left radial–cephalic AVF is created in a right-hander and vice versa However, a right radial–cephalic AVF must be considered in a right-hander when the cephalic veins in the left forearm are compromised
Vascular access guideline recommendations stipulate that an upper arm cephalic AVF, arising from the brachial or radial artery in the case of high brachial artery bifurcation, must be considered whenever creation of a radial–cephalic fi stula is not technically possible or failed in both forearms The cephalic vein, which is usually super fi cial at the elbow (a common site for venipuncture injuries), rapidly takes a deep course more cephalad and sometimes requires some form of secondary super fi cialization In France, the option of creating a distal forearm AVF with its
in fl ow coming from the ulnar artery (wrist ulnar–basilic AVF) is considered before jumping to a brachial–cephalic AVF The ulnar–basilic AVF is still the Cinderella of vascular access due to the limited number of published cohort studies on its creation and outcomes and due primarily to the fact that the distal basilic vein with its infe-rior-medial course makes cannulation of the arterialized segment possible only in a
fl exed elbow and slightly pronated position, the latter reason being a major bling block to general acceptance One solution to this problem is to transpose the arterialized vein to an anterolateral position and anastomose it to the radial artery (transposed radial–basilic AVF) Higher arterial fl ow from the usually more domi-nant radial artery ensures better access fl ow Distal forearm basilic AVFs, whether transposed or not, are rarely cannulatable by six weeks after creation, compared to brachial–cephalic AVFs, most of which can be cannulated at one month Hence, direct wrist ulnar–basilic or transposed radial–basilic fi stulas would be the ideal in a young patient in whom venous capital preservation is a paramount concern In con-trast, it is of lesser importance in a patient requiring dialysis initiation in the shortest delay and who would therefore be better off with a brachial–cephalic AVF
A brachial–basilic AVF with mandatory super fi cialization should be the next consideration whenever forearm or brachial–cephalic AVFs are not possible The basilic vein, irrespective of patient’s body habitus, is only super fi cial at its fi rst few centimeters at the elbow before taking a deep course below the medial upper arm fascia Cannulating a non-super fi cialized brachial–basilic AVF is hence not only discouraged but also not an easy task in addition to running the risk of injuring the brachial artery adjacent to it Inadvertent cannulation of the brachial artery may result in catastrophic hematoma and pseudoaneurysm formation
A prosthetic graft connecting the brachial artery to an upper arm vein (cephalic, basilic, or axillary) is usually considered as a last resort once all the veins in the upper limb are deemed unsuitable for AVF creation, provided that the central veins are patent Grafts are either straight or looped and have both arterial and venous anastomoses Grafts linking the radial artery to an elbow or upper arm vein have also been anecdotally described but are not mentioned in the clinical guidelines as
a valuable conventional option
Trang 2514 3 Access Creation Strategy
In young patients, prior to placement of an undesirable prosthetic graft, some surgeons would create an autogenous fi stula between the brachial artery and a deep brachial vein, which requires a second stage of super fi cialization as for brachial–basilic fi stulas Unfortunately, results are frequently disappointing [ 6 ]
Lower limb followed by exotic accesses are next considered after all upper limb options (AVFs or grafts) have been exhausted The creativity and skills of surgeons and anatomic considerations take the upper hand in pushing the boundaries for vas-cular access creation in these desperate situations (AVFs: femoral–femoral, popliteal–saphenous; grafts: femoral–femoral, axillary–popliteal, “necklace” axil-lary–axillary, axillary–subclavian ipsilateral or contralateral, carotid–jugular, right atrial bypasses, etc.) The invasive and high-risk nature of these surgical procedures with questionable outcomes makes the option of long-term tunneled catheters (jug-ular, subclavian, femoral, translumbar, transhepatic, transrenal) therefore more attractive Indeed, these end-stage accesses are more the exception than the rule in
a well-experienced, well-trained, and well-equipped multidisciplinary team setting, whereas they are more common in centers which embrace the less desirable throm-bosed access–tunneled catheter–new access creation triad
In summary, surgeons entrusted with creating vascular access should do so in close collaboration and consultation with nephrologists, sonographers, and inter-ventional radiologists This is not an easily learned and maintained craft It is always
in the ESRD patient’s best interest to create forearm AVFs, even when the vessels are suboptimal Such a strategy de fi nitely results in a higher rate of technical and maturation failure It is the nephrologists’ prime role to educate patients and rela-tives alike not to misinterpret these failures as surgical incompetence or misadven-ture The key message should be that creating the ideal vascular access remains a major challenge given that patients initiating dialysis are now getting older and have more comorbidities than 20 years ago
References
1 Schwab S, Besarab A, Beathard G et al (1997) NKF-DOQI clinical practice guidelines for vascular access Am J Kidney Dis 30:S150–S189
2 National Kidney Foundation’s KDOQI (2006) Clinical Practice guidelines for vascular access
Am J Kidney Dis 48(suppl 1):S176–S273
3 Huijbregts H, Blankestijn P (2006) Dialysis access guidelines for current practice Eur J Vasc Endovasc Surg 31:284–287
4 Tordoir J, Canaud B, Haage P (2007) European best practice guidelines on vascular access Nephrol Dial Transplant 22(Suppl 2):ii88–ii117
5 Sidawy A, Spergel L, Besarab A et al (2008) The Society for Vascular Surgery: clinical practice guidelines for the surgical placement and maintenance of arteriovenous hemodialysis access
J Vasc Surg 48:2S–25S
6 Jennings W, Sideman M, Taubman K, Broughan T (2009) Brachial vein transposition venous fi stulas for hemodialysis access J Vasc Surg 50:1121–1125
Trang 26L Turmel-Rodrigues, C.J Renaud, Diagnostic and Interventional Radiology
of Arteriovenous Accesses for Hemodialysis,DOI 10.1007/978-2-8178-0366-1_4,
© Springer-Verlag France 2013
The rate at which the feeding artery and arterialized vein develop after AVF creation depends on individual patient characteristics and location of the anastomosis
Under ideal conditions, blood fl ow in a fi stula should increase inde fi nitely in tandem with the diameter of the feeding artery and out fl ow vein However, the development of stenoses usually impedes this natural process When such stenoses gradually worsen, access fl ow inversely lessens reaching a critical point, which ter-minates as access thrombosis
The pathogenesis of access stenosis is not well-known and understood [ 1, 2 ] Neointimal hyperplasia more commonly develops at the anastomosis or swing point
of forearm fi stulas, at the venous anastomosis of grafts, and at the junctional ment of super fi cialized veins Factors at play in neointimal hyperplasia are likely endothelial trauma and the subsequent release of pro-in fl ammatory and pro- fi brotic mediators Central vein stenosis resulting from catheter placement in the internal jugular and subclavian veins is a good point illustration
seg-Normal blood fl ow in any vascular access should be between 500 and 1,500 mL/min
Hyper fl ow is de fi ned as fl ow greater than 1.5–2 L/min, while low fl ow is usually less than 500 mL/min Upper arm AVFs are more likely to develop hyper fl ow
Chapter 4
Natural History of Vascular Access
Luc Turmel-Rodrigues and Claude J Renaud
L Turmel-Rodrigues , M.D ( * )
Department of Vascular Radiology , Clinique St-Gatien ,
8 place de la cathédrale , 37000 Tours , France
Department of Vascular Radiology , Clinique Ambroise Paré ,
25 boulevard Victor Hugo , 92200 Neuilly-sur-Seine , France
e-mail: luc.turmel@wanadoo.fr
C J Renaud , M.D
Department of Medicine , Khoo Teck Puat Hospital, Alexandra Health ,
90 Yishun Central , Singapore 768828 , Singapore
e-mail: renaudcj@hotmail.com
Trang 2716 4 Natural History of Vascular Access
Fig 4.1 ( a ) This brachial artery has fed a forearm fi stula for 17 years and developed major
aneurysmal degeneration with stretching and thinning of the overlying skin ( arrows ) Hyper fl ow
and subsequent enlargement of the arterialized vein were successfully controlled by arterial
liga-tions at the anastomosis ( b ) Arteriography via the femoral artery shows a huge markedly tortuous
brachial artery
Fig 4.2 Typical appearance of hyper fl ow in an old radial–cephalic AVF with diffuse aneurysmal
degeneration of the vein
Trang 2817 References
whereas forearm AVFs may remain patent for months despite an access fl ow of less than 200 mL/min
Some AVFs will mature without impediments and develop very high access
fl ow In this process, the feeding arteries become tortuous and aneurysmal, while the arterialized veins fold back upon themselves and develop locally sharp angula-tion due to overlap of adjacent aneurysms (Figs 4.1 and 4.2 ) These abnormal ves-sels can be challenging to treat Ligation of such AVFs often results in thrombosis
of the aneurysmal sac and subsequently of the main feeding artery as a result of reduced out fl ow
The most common cause of AVF loss is thrombosis when attempts at cular or surgical recovery are not performed timely enough or are unsuccessful Other causes include skin necrosis at cannulation sites, unresectable aneurysms, arm edema secondary to intractable central vein stenosis, distal ischemia (steal syndrome), severe heart failure, and rarely infection
Grafts are usually abandoned after recurrent unsalvageable end-stage thrombosis and ligation and/or excision arising from severe infection
References
1 Roy-Chaudhury P, Arend L, Zhang J et al (2007) Neointimal hyperplasia in early arteriovenous
fi stula failure Am J Kidney Dis 50:782–790
2 Wang Y, Krishnamoorthy M, Banerjee R et al (2008) Venous stenosis in a pig arteriovenous
fi stula model: anatomy, mechanisms and cellular phenotypes Nephrol Dial Transplant 23: 525–533
Trang 29L Turmel-Rodrigues, C.J Renaud, Diagnostic and Interventional Radiology
of Arteriovenous Accesses for Hemodialysis,DOI 10.1007/978-2-8178-0366-1_5,
© Springer-Verlag France 2013
5.1 Arterial Anatomy
The subclavian artery supplies the entire upper limb On the left, it arises directly from the aortic arch On the right, it arises from the brachiocephalic trunk The subclavian artery gives rise to the vertebral, internal mammary (thoracic) arteries, and thyrocervical trunk before becoming the axillary artery in the axillary space at the lateral border of the fi rst rib The axillary artery in turn becomes the brachial artery at the lower border of teres major after branching out as the thoracic, thora-coacromial, external mammary, and circum fl ex humeral arteries The brachial artery courses along the length of the upper arm giving off several muscular branches (Fig 5.1 )
Chapter 5
Radiological Anatomy and Preoperative
Imaging of Upper Limb Vessels
Luc Turmel-Rodrigues , Jean-Jacques Godier , Claude J Renaud ,
and Richard Shoenfeld
L Turmel-Rodrigues, M.D ( * )
Department of Vascular Radiology , Clinique St-Gatien ,
8 place de la cathédrale , 37000 Tours , France
Department of Vascular Radiology , Clinique Ambroise Paré ,
25 boulevard Victor Hugo , 92200 Neuilly-sur-Seine , France
e-mail: luc.turmel@wanadoo.fr
J-J Godier , M.D
Department of Vascular Radiology , Clinique St-Hilaire ,
2 place St-Hilaire , 76000 Rouen , France
e-mail: mygod@wanadoo.fr
C J Renaud, M.D
Department of Medicine , Khoo Teck Puat Hospital, Alexandra Health ,
90 Yishun Central , Singapore 768828, Singapore
e-mail: renaudcj@hotmail.com
R Shoenfeld, M.D
Department of Interventional Radiology , The Access Center at West Orange ,
741 North fi eld Avenue, Suite 105 , West Orange , NJ 07052 , USA
e-mail: rshoenfeld@yahoo.com
Trang 3020 5 Radiological Anatomy and Preoperative Imaging of Upper Limb Vessels
After crossing the inter-epicondyle line, the brachial artery trifurcates in the upper fourth of the forearm into the radial (usually the more dominant branch), ulnar, and interosseous (also called “median”) arteries The radial artery gives off two terminal branches at the wrist, near the anatomical snuffbox These then anas-tomose with terminal branches from the ulnar artery to form the super fi cial and deep palmar arches which may have several anatomical variants The deep arch takes a straight and short convex course inferiorly, while the super fi cial arch is more tortu-ous and ends approximatively 1–2 cm below the base of the metacarpals (Fig 5.2 ) The anatomy of the digital arteries which arise from the convexity of the arcades is also subject to variability Each digit is supplied by the medial and lateral digital arteries, both terminating in the distal pulp space
Anatomical variability is a common feature of upper limb vasculature Vascular radiologists, despite years of experience, sometimes encounter dif fi culties in deci-phering normal from aberrant anatomy during fi stulography The subclavian artery rarely presents with variant anatomy except for an aberrant right subclavian artery that arises from the aortic arch beyond the origin of the left subclavian artery It then crosses the midline posterior to the esophagus to supply the right upper limb Variant anatomy more commonly involves the brachial artery, particularly at the elbow The most common is a high origin of the radial artery (15–20 % of cases) The radial artery may originate at any level from the axillary artery to the elbow (Fig 5.3 ) Thereafter, the other arterial segment is no longer the brachial artery but the
Carotid artery Brachiocephalic trunk Axillary
artery
Brachial artery
Interosseous artery Radial artery
Ulnar artery
Deep palmar arch Superficial palmar arch
Subclavian artery
Fig 5.1 Normal arterial anatomy of the
upper limb
Trang 3121 5.1 Arterial Anatomy
ulnar–interosseous trunk, which ultimately gives off the ulnar and interosseous branches below the elbow An interesting phenomenon frequently associated with a high radial artery origin is the formation of an anastomotic arcade between it and the ulnar–interosseous trunk in the upper third of the forearm (Fig 5.4 ) The caliber of this anastomotic arcade is usually smaller than that of the radial artery but can increase
in size if there is a stenosis on the proximal radial artery (Figs 5.5 and 5.6 )
Fig 5.2 Arteriogram
showing the super fi cial and
deep palmar arches
Carotid artery Brachiocephalic trunk
Radial artery
Interosseous artery Ulnar artery
Deep palmar arch Superficial palmar arch
Axillary artery
Ulnar-interosseous trunk
Radial artery
Subclavian artery
Fig 5.3 The most common
arterial anatomical variant: a
high origin of radial artery
The diagram also shows a less
common high bifurcation of the
radial artery in the forearm
Trang 3222 5 Radiological Anatomy and Preoperative Imaging of Upper Limb Vessels
The ulnar artery can, to a lesser extent, have a high origin and then accompanies the main radial–interosseous trunk down the upper arm (Fig 5.7 ) An interosseous artery with a high origin is extremely rare
The terminal branches of the radial artery may bifurcate in the mid-forearm, several centimeters above the wrist, such that an AVF arising from it is fed by one
of the terminal branches instead of the main trunk (Figs 5.3 and 5.8 ) Numerous collaterals can also form between the radial, interosseous, and ulnar arteries in the forearm as a result of proximal radial artery stenosis (Fig 5.9a, b )
At the wrist and hand, complete palmar arches are more the exception than the rule The arches are more commonly asymmetric and incomplete with hypotrophic
or stenotic segments The digital arteries are not always aligned and symmetrical and may give off tiny collaterals particularly in recurrently traumatized areas
5.2 Venous Anatomy
There are two types of veins in the upper extremity: super fi cial veins found diately beneath the skin and deep veins which accompany the arteries and constitute the venæ comitantes of those vessels Only super fi cial veins are suitable for AVF creation in the forearm
imme-Carotid artery Brachiocephalic trunk
Radial artery
Interosseous artery Ulnar artery
Deep palmar arch Superficial palmar arch
Axillary artery
Ulnar-interosseous trunk
Radial artery Anastomotic arcade
Subclavian artery
Fig 5.4 Illustration showing the
sometimes-present supernumerary
anastomotic arcade at the elbow
between the radial artery and the
ulnar–interosseous trunk
Trang 3323 5.2 Venous Anatomy
Despite having more anatomical variation than arteries, the cephalic and basilic veins are predominantly seen veins in the forearm and upper arm of normal subjects
The main cephalic vein drains from a venous network on the dorsal aspect of the hand at the posterolateral border of the wrist It winds posteroanteriorly and then lateromedially toward the elbow where it joins the median basilic (cubital) vein medially and the median cephalic vein laterally which ascends as the upper arm cephalic vein
The accessory cephalic vein usually arises from the main cephalic vein at its middle third and takes a lateral course toward the elbow before joining the median cephalic vein in the upper lower of the upper arm It sometimes has a more distal origin from the dorsal venous network at the wrist (Fig 5.11 ) From there, it takes a variable course as a vein with either duplicate segments or multiple tributaries
The basilic vein begins posteromedially from the dorsal venous plexus at the wrist and courses along the medial border of the forearm and curves laterally at the elbow
to join the median cubital vein at the lower third of the upper arm forming the upper arm basilic vein The forearm basilic vein may be duplicated along its course At the elbow, the accessory cephalic, main (median) cephalic, median cubital, and forearm basilic veins converge to form a venous network in the shape of a capital “M.”
Carotid artery Brachiocephalic trunk
Radial artery
Interosseous artery Ulnar artery
Deep palmar arch Superficial palmar arch
Axillary artery
Ulnar-interosseous trunk
Radial artery Anastomotic arcade
Subclavian artery
Fig 5.5 The radial artery may be
atrophied or occluded above the
elbow Its forearm segment may
only be supplied by the
supernumerary anastomotic arcade
Trang 3424 5 Radiological Anatomy and Preoperative Imaging of Upper Limb Vessels
The deep veins of the forearm are small in caliber and accompany the three main arteries as their venae comitantes, uniting in front of the elbow to form the two bra-chial veins that run parallel to the brachial artery The deep brachial veins are linked
at the elbow with the super fi cial veins by a perforating vein which varies in shape and size
c
radial artery
artery radial
Fig 5.6 ( a ) This arterial phase of a low fl ow radial–cephalic fi stula shows what appears to be a
strange, tortuous origin of the radial artery This is in fact the anastomotic arcade from the ulnar– interosseous trunk which opaci fi es the upper arm portion of the radial artery before the brachial
portion seen on ( b ) ( b ) This upper arm run shows the high origin of the radial artery ( c ) This later
phase shows opaci fi cation of the upper arm segment of the high-origin radial artery This delay is caused by a radial artery stenosis or spasm at the elbow There is also a distal peri-anastomotic radial artery stenosis that will be dilated via a retrograde venous approach
Trang 3525 5.2 Venous Anatomy
Carotid artery Brachiocephalic trunk
Interosseous artery Ulnar artery
Deep palmar arch Superficial palmar arch
Axillary artery
Radial artery Radial-interosseous trunk
Subclavian artery
Fig 5.7 High origin of the ulnar
artery
Fig 5.8 This arteriogram of a radial–cephalic fi stula shows
that the anastomosis was created with one of its two terminal
branches rather than the radial artery itself
Trang 3626 5 Radiological Anatomy and Preoperative Imaging of Upper Limb Vessels
Fig 5.9 ( a and b ) These two phases of
the same arteriogram with forearm prone
show a high radial–cephalic fi stula with
a severe peri-anastomotic stenosis
Numerous collaterals run from the ulnar
and interosseous arteries to the distal
radial artery whose retrograde fi lling
compensates the proximal stenosis
Internal jugular vein
Superior vena cava
Median cubital vein
Forearm basilic vein Forearm cephalic vein
Left brachio-cephalic (Innominate) trunk
Right brachio-cephalic (innominate) trunk
Fig 5.10 Normal
non-variant venous anatomy,
rarely seen in practice in
the forearm
Trang 3727 5.2 Venous Anatomy
The perforating vein plays an important role in diverting blood fl ow from radial–cephalic AVFs to the central veins via the deep veins in the event of median cephalic and/or basilic vein occlusion at the elbow Its course is variable: short, long, straight, curved, convex, and convoluted
The basilic vein arising from the convergence of the forearm basilic and median cubital vein courses cephalad obliquely along the medial border of the upper arm super fi cially for a few centimeters After perforating the deep fascia, it ascends and joins the deep brachial veins to form the axillary vein at the upper third of the upper arm Usually single, the axillary vein may be duplicated such that the two or three segments rejoin to form the subclavian vein at the lower border of fi rst rib The subclavian vein joins the internal jugular vein at the head of the clavicle to form the brachiocephalic (also called “innominate”) vein
The upper arm cephalic vein arises from the convergence of the main and accessory forearm cephalic veins and ascends the upper arm anterolaterally before piercing the clavipectoral fascia to enter the deltopectoral triangle at a more or less acute angle (cephalic arch) It then joins the subclavian vein just below the clavicle In the presence
of vascular access via the cephalic vein, the cephalic arch is particularly prone to form stenoses which may be dif fi cult to dilate It is also prone to early and recurrent stenoses The cephalic arch may be bi fi d or may directly collateralize with the internal or external jugular veins (Fig 5.12 ) The arch can also bypass the subclavian vein and directly enter the brachiocephalic trunk
Internal jugular vein
Superior vena cava
Median cubital vein
Forearm basilic vein Forearm cephalic vein
Left brachio-cephalic (innominate) trunk
Right brachio-cephalic (innominate) trunk
Fig 5.11 Principal variant
anatomy, with isolated low
origin of the accessory
cephalic vein, duplications
and cephalic arch variants
Trang 3828 5 Radiological Anatomy and Preoperative Imaging of Upper Limb Vessels
The two brachial veins accompanying the brachial artery merge with the basilic vein to form the axillary vein at an equally tight angle at the lower border of the teres major The constituted arch is prone to form stenoses whenever the deep veins are used (rarely) for vascular access creation
5.3 Preoperative Radiological Imaging
5.3.1 Indications
Nephrologists and surgeons are increasingly aware of the limitations of physical examination as a tool to assess arterial and venous anatomy prior to creating a vas-cular access Greater emphasis is now being placed upon more objective methods Arterial mapping is feasible almost exclusively by color duplex ultrasound Arteriography is super fl uous except in the presence of severe atherosclerosis CT angiography and magnetic resonance angiography play an equally shrinking role due to high contrast load and risk of contrast nephropathy in pre-dialysis patients and risk of nephrogenic systemic fi brosis with some gadolinium contrast agents Both modalities require venipuncture, which may deplete venous capital in non-experienced hands In addition, neither modality provides essential hemodynamic data such as volume fl ow and velocity
Imaging of the veins (venous mapping) is indicated if there are abnormal or inadequate fi ndings on physical examination or whenever central vein stenosis is suspected Venous mapping determines the size, depth, course, collaterality, and quality of the veins in the upper extremity as well as central vein patency Iodinated contrast venography and later carbon dioxide venography were the venous mapping modalities of choice before the advent of ultrasonographic mapping in the 1990s Color duplex ultrasonography has many advantages over venography It is noninva-sive and non-irradiating Its disadvantages are that results are very operator- dependent, and the central veins (subclavian and brachiocephalic veins and superior vena cava) cannot be adequately evaluated Venography is selectively indicated in patients with a history of central vein catheterization (acute or tunneled dialysis
Fig 5.12 Fistulogram
showing a double duplication
of the cephalic arch with one
branch (normal anatomy) is
joining the subclavian vein,
the second communicating
with the external jugular
vein, and the third emptying
directly into the
brachiocephalic vein
Trang 3929 5.3 Preoperative Radiological Imaging
catheters, central lines for critical care or chemotherapy, cardiac rhythm modifying devices) to exclude central vein obstruction It is still heavily performed in centers where the quality and accuracy of color duplex ultrasonography are doubtful Moreover, venograms can be personally reviewed by the attending surgeons and directly correlated with physical fi ndings This is in contrast to ultrasound venous mapping, which unless performed by trained surgeons themselves are outsourced to ultrasound technologists or radiologists, leaving the surgeons only with a report and selected images to which they must correlate their physical fi ndings Venography is also better than ultrasound at depicting arterial calci fi cation
in CO 2 retainers with chronic obstructive pulmonary disease or patients with to-left cardiac shunts In such cases, 10 mL of 90 % diluted iodinated contrast can
right-be used in each limb in order to minimize CN and RRF loss
It is best to apply an anesthetic gel (lidocaine) at the venipuncture site, preferably the lateral dorsal aspect of the hand, 30 min before venography The more distal and lateral the venipuncture, the better is visualization of the cephalic vein in the fore-arm (Fig 5.13 ) A 20- to 22-G cannula is used for venipuncture A tourniquet is placed in the upper arm prior to venipuncture to allow the distal veins to dilate Vein dilation can be further enhanced and spasm prevented by warming the forearm with
a hair dryer for at least 10 min Intravenous injection of a vasodilator such as glycerin may be useful to prevent venospasm once the vein is cannulated but is rarely used because of side effects such as headache, vomiting, and hypotension Immersing the arm in warm water has the same effect but may not be practical in an angio suite The arm should be placed in the supine and abducted position to mini-mize compression of basilic vein out fl ow at the axilla
A minimum of four angiographic runs is taken: forearm with and without quet (Fig 5.14 ), upper arm (Fig 5.15 ), and upper thorax (Fig 5.16 ) Additional runs may be obtained in different views or after the reapplication of tourniquet should the initial imaging be unsatisfactory Veins that fail to opacify can be visual-ized by adopting some simple techniques For instance, if there is inadequate opaci fi cation of the upper arm cephalic vein, the basilic vein should be compressed
tourni-by squeezing a bottle between the adducted upper arm and the thorax near the axilla
Trang 4030 5 Radiological Anatomy and Preoperative Imaging of Upper Limb Vessels
to allow preferential re fl ux into the cephalic vein Poor opaci fi cation of the basilic vein can be enhanced by tightening a tourniquet applied over the cephalic vein at the lateral aspect of the mid-upper arm
CO 2 venography requires angiographic equipment capable of rapid exposures (6 frames/s) digital subtraction and image stacking Each angiographic run neces-sitates 50–60 mL of carbon dioxide It is important to allow 45–60 s between injec-tions and to massage the vein segment under study after each carbon dioxide bolus
Fig 5.14 ( a ) This iodine
venography in the forearm
showed a nice cephalic vein
( b ) CO 2 venography in the
same patient
Fig 5.13 ( a ) Cannulation of a vein of the dorsum of the hand and ( b ) cannulation of a vein of the
thumb for venographies