Summary of medical doctoral dissertatation: study on the value of magnetic resonance imaging, laparoscopic surgery and cholangioscopic lithotripsy through choledocho cutaneous channel in the treatment of main bile duct stones

However, laparoscopic surgery combined with cholangioscopy is still challenging due to various causes including: difficult manipulation of the cholangioscope due to increasing gap betwee

Specialty: Digestive Surgery Code: 62720125

SUMMARY OF MEDICAL DOCTORAL DISSERTATATION

Hanoi – 2021

THIS STUDY WAS CONDUCTED AT 108 INSTITUTE OF CLINICAL MEDICAL AND PHARMACEUTICAL SCIENCES

The dissertation will be defended at thesis defense council at:

108 Institute of Clinical Medical and Pharmaceutical Sciences At day month 2021

Further reference to the thesis at:

1 Vietnam national library

2 108 Institute of clinical medical and pharmaceutical sciences library

INTRODUCTION

Gallstone disease is a common disease in Vietnam (3.32 - 6.11%

of the population) as well as in other countries around the world which is associated with complicated disease progression, numerous serious complications and even death if not treated promptly, especially in case of intrahepatic gallstones

To effectively treat gallstone disease, it is necessary to accurately determine the location, the number of stones, and abnormal biliary tract anatomy to choose the appropriate treatment method Magnetic resonance imaging is the most chosen method for gallstone evaluation because of many advantages However, there have not been many studies on the imaging characteristics as well as the value

of magnetic resonance imaging in the diagnosis of gallstones in our country Therefore, further studies were needed to clarify the issue

In Vietnam, laparoscopic surgery for gallstone disease started in

1992 at Cho Ray hospital Along with the development of science and technology, cholangioscopes as well as different methods of lithotripsy and stone retrieval have been used Consequently, laparoscopic surgery combined with cholangioscopy has been widely applied in the treatment of cholelithiasis However, laparoscopic surgery combined with cholangioscopy is still challenging due to

various causes including: difficult manipulation of the cholangioscope due to increasing gap between the common bile duct and the abdominal wall when the abdomen is inflated, difficulty in maintaining the water pressure to dilate the bile ducts due to continuous water leak at the site of the bile duct opening, spillage of stone fragments and bile into the abdominal cavity leading to the need of continous suctioning, prolonged operative time and potential

residual abscess formation To overcome these above-mentioned

disadvantages, Vo Dai Dung et al had created a cutaneous channel through which cholangioscopic lithotripsy can be performed

However, there was still a lack of comprehensive research on this issue in our country Therefore, we decided to perform the thesis:

“Study on the value of magnetic resonance pancreato, laparoscopic surgery and cholangioscopic lithotripsy through choledocho- cutaneous channel in the treatment of main bile duct stones” with

Chapter 1 LITERATURE REVIEW 1.1 The value of magnetic resonance imaging in the diagnosis of cholelithiasis

1.1.1 In other countries

In developed countries, magnetic resonance cholangiopancreatography (MRCP) has long been considered the most comprehensive method for assessing biliary pathologies including cholelithiasis There have been many studies on imaging characteristics and values of MRCP in the evaluation of cholelithiasis

Many other studies compared other imaging methods including ultrasound, CT scan, endoscopic ultrasound and endoscopic retrograde cholangiopancreatography (ERCP) with MRCP Some authors concluded that MRCP can replace ERCP in the diagnosis of choledochal stones

The results from studies of other countries showed that the values of MRCP in the diagnosis of cholelethiasis were as followed: sensitivity 91-100%, specificity 90-100%, positive predictive value 82 to 96 %, and negative predictive value 96 - 100%

1.1.2 In Vietnam

In Vietnam, there have been many studies on the chemical composition of gallstones, on the pathogenesis of gallstones, and on the values of different diagnostic imaging modalities in the diagnosis of cholelithiasis including plain radiograph, ERCP, T tube cholangiogram, ultrasound, intraoperative ultrasound

Studies in Vietnam on the value of MRCP in the diagnosis of cholelithiasis showed sensitivity of 92.5 - 100%, specificity of 83.3 - 90.9%, positive predictive value of 96.2 - 98% and negative predictive value of 80 - 100%

1.2 Results of laparoscopic surgery and cholangioscopic lithotripsy through choledocho-cutaneous channel in the treatment of main bile duct stones

1.2.1 In other countries

Main bile duct Gallstones in Western countries are usually secondary stones migrating from the gallbladder which are usually small, in small number, often coexist with gallbladder stones, and are located below the cystic duct without intrahepatic stones Therefore, transcystic stone removal is associated with resonable success rate of 50.4- 82.5% In contrast, in Asian countries such as Hong Kong, India, transcystic stone removal is not as common compared to Western countries There have been an increasing number of studies

on the application of laparoscopic surgery in the treatment of gallstones with broadening indications However, there was no research on laparoscopic treatment of main bile duct stones with the use of cholangioscopic lithotripsy and choledocho-cutaneous channel

Overall results of studies using cholangioscopy to treat gallstones around the world were as followed: success rates of 85 - 99%, complication rate of 3.4 - 21.4% (most common complications were infection and postoperative bile leakage) Bile leakage was the main

cause of death after surgery Residual stone rate was 3.1 - 13% 1.2.2 In Vietnam

The first cholecystectomy in Vietnam was performed at Cho Ray Hospital in 1992 followed by a rapid increase in number of studies

on laparoscopic treatment of other diseases In 1998, also at Cho Ray Hospital, abdominal wall-lifting laparoscopic exploration of the common bile duct to treat gallstones was first performed In 1999,

Ho Chi Minh City University of Medicine and Pharmacy Hospital performed conventional laparoscopic transcystic and transcholedochal common bile duct exploration In 2000, Viet Duc Hospital and Hue Central Hospital started laparoscopic treatment common bile duct stones

Overall results of studies on laparoscopic surgery using cholangioscopy to treat gallstones in Vietnam showed the following results: success rate 86.49 - 100%, complication rate 3.9-11 21% with the most common complications being infection, bile leakage and residual abscess requiring reoperation

In Vietnam, in order to overcome the above-mentioned limitations

of laparoscopic surgery combined with cholangioscopy, Le Nguyen Khoi et al had created a choledocho-cutaneous channel through which gallstones can be removed However, Vo Dai Dung was the first author who reported 43 cases of intrahepatic stones with or without extrahepatic stones treated with laparoscopic surgery and cholangioscopy through this channel with good results

Therefore, cholangioscopy and especially the

choledocho-cutaneous channel plays an important role in laparoscopic treatment

of cholelithiasis by reducing the difficulties in controlling the flexible cholangioscope as well as the rate of stones and bile spillage into the abdominal cavity, reducing the operative time, increasing the rate of stone clearance, and reducing abdominal cavity infection as well as the postoperative residual abscess rates In Vietnam, the application of cholangioscopy and choledocho-cutaneous channel was still limited This study aimed to clarify the role of laparoscopic surgery, cholangioscopy through the choledocho-cutaneous channel

in the treatment of cholelithiasis

Chapter 2 SUBJECTS AND METHODS

2.1 SUBJECTS

2.1 Study subjects

Including 84 patients diagnosed with main bile duct stones, treated with laparoscopic surgery combined with cholangioscopic lithotripsy through the choledocho-cutaneous channel at Department

of Hepato-Biliary and Pancreatic Surgery of 108 Military Central Hospital from June 2017 to March 2020

2.1.1 Inclusion criteria:

- Patients with a positive diagnosis of main bile duct stones (confirmed in surgery), offered magnetic resonance cholangiopancreatography (MRCP) and common bile duct diameter

of ≥ 8mm (on MRCP)

- Patients received laparoscopic surgery combined with cholangioscopy through the chodedocho-cutaneous channel (LS-CCC) as treatment

- Patients agreed to participate in the study

2.1.2 Exclusion criteria:

- Contraindications of general anesthesia needed for laparoscopic

surgery

- Common bile duct diameter < 8mm on MRCP

- Indications for hepatectomy e.g biliary stenosis-induced focal liver atrophy

- Patients refused to participate in the study

2.2 STUDY METHODS

2.2.1 Study design: a descriptive, propective study

2.2.2 Study parameters

2.2.2.1 General characteristics of patients

* Clinical characteristics

- Age, gender

- Clinical characteristics: pain, fever, jaundice, Charcot triads

- History: number of previous ERCP, open common bile duct (CBD) exploration, CBD exploration and cholecystectomy, cholecystectomy, other abdominal operations

- Comorbidities: cardiovascular diseases, pulmonary diseases, diabetes, cirrhosism, etc…

* Paraclinical characteristics

Blood tests:

- Hematologic: white blood cell counts, neutrophil rate

- Biochemistry: total bilirubin, SGOT, SGPT

- Coagulation panel: prothrombin ratio

Hepatobiliary ultrasound:

- Biliary tract: common bile duct, right and left hepatic ducts sizes

- Bile duct stones: position, size, number

MRCP:

- Biliary tract: common bile duct, right and left hepatic ducts sizes, stricture location

- Bile duct stones: position, size, number

2.2.2.2 Value of MRCP in the diagnosis of cholelithiasis

- Stone position determined by MRCP

- Stone position determined intraoperatively

- Stone number determined by MRCP : small vs large number

- Stone number determined intraoperatively: small vs large number

- Biliary stricture location determined on MRCP and intraoperatively

- Determine the value of MRCP in the diagnosis of stone position, number, biliary strictures by comparing with intraoperative findings to calculate the Sensitivity, specificity, accuracy, positive predictive value, negative predictive value using 2 x 2 tables

2.2.2.3 Results of LS-CCC in the treatment of main bile duct stones

* Intraoperative characteristics

- Number of trocarts used: 4 trocarts, 5 trocarts

- Abdominal cavity condition: no adhesion, mild adhesion, severe adhesion

- Presence of bilary drainage: yes/no

- Cholecystectomy: yes/no

- Subhepatic drainage: yes/no

- Complications: hemorrhage, injuries of portal vein, hepatic artery, duodenum, colon, etc…

- Operative time: counted from skin incision of the first trocart to closure of the last trocart (minutes)

Placement of choledocho-cutaneous channel (CCC):

- Successful placement of CCC: yes/no

- Placement time (mins)

- Difficulties: biliary injury, CCC dislodgement during stone removal, stone and bile spillage into the abdominal cavity

Cholangioscopy through CCC

- Stone position, stone number (large vs small number)

- Biliary stricture: mild/moderate/severe stricture

- Sphincter of Oddi: normal/stenosed

- Stone removal:

+ Methods: Mirrizi forcep, basket, lithotripsy

+ Number of stones removed: small vs large number

+ Stone clearance: observed stone cleared vs retained

+ Retained stones: position, causes

- Time of stone removal: from the start to the end of stone removal (mins)

* Early postoperative results

- Pain duration: based on postoperative analgesic use duration (days)

- Time to return of bowel function: from surgery to first flatus (days)

- Time to subhepatic drain removal: from surgery to drain removal (days)

- Hospital stay: from surgery to discharge (days)

- Early complications: hemorrhage, postoperative fluid collection, intestinal fistula, biliary fistula, others…

Stone clearance results

- Ultrasound examination:

+ Stone clearance: yes/no

+ Retained stones: position

- Cholangiography:

+ Stone clearance: yes/no

+ Retained stones: position

- Cholangioscopy: yes/no

Stone clearance was assessed by three modalities: cholangioscopy, ultrasound, cholangiography Stone clearance was defined as no retained stones detected on all three modalities

Factors associated with stone clearance:

- Stone position

- Stone number

- Biliary strictures

- Surgical history

* Follow-up results

- Follow-up: yes/no

- Follow-up types: regular/irregular

- Time to follow-up: from surgery to follow-up day (days)

- Ultrasound + Stone cleared/retained

+ Retained stoned position

- Management of retained stones

+ Removal of biliary drain + Trans T-tube CBD exploration: number of procedures, suceess/failure of stone clearance

Results of surgery classification (criteria of the study group)

- Good: + Successful placement of CCC

+ Stone clearance

+ No complications

- Fair: + Successful placement of CCC

+ Retained stones or complications requiring only conservative therapies

- Average: + Failure of placement of CCC

+ Reoperation due to complications

- Bad: postoperative death

2.2.4 Data analysis

- All data were encrypted and inputted into a computer and then processed using SPSS 20.0 software

- The difference was considered statistically significant when p < 0.05

- Determine the values of MRCP in terms of the diagnosis of location, the number of stones of the CBD, RHD, LHD: sensitivity, specificity, accuracy, positive predictive value, negative predictive value (using 2x2 tables)

Chapter 3 RESULTS 3.1 Value of MRCP in the diagnosis of main bile duct stones

- Diagnosis of the position of extrahepatic stones: sensitivity: Se = 97.05%, specificity: Sp = 93.75%, accuracy: Acc = 96.42%, positive predictive value : PPV = 98.51%, negative predictive value: NPV = 88.23%

- Diagnosis of the position of right liver bile duct stones: sensitivity: Se = 95.65%, specificity: Sp = 94.73%, accuracy: Acc = 95.23%, positive predictive value : PPV = 95.65%, negative predictive value: NPV = 94.73%

- Diagnosis of the position of left liver bile duct stones: sensitivity:

Se = 96.49%, specificity: Sp = 88.88%, accuracy: Acc = 94.04%, positive predictive value : PPV = 94.82%, negative predictive value: NPV = 92.30%

- Diagnosis of the number of main bile duct stones: sensitivity: Se

= 77.77%, specificity: Sp = 98.66%, accuracy: Acc = 96.42%, positive predictive value: PPV = 87.50%, negative predictive value: NPV = 97.36%

- Diagnosis of biliary strictures: sensitivity: Se = 93.75%, specificity: Sp = 100%, accuracy: Acc = 98.81%, positive predictive value: PPV = 100%, negative predictive value: NPV = 98.55%

3.2 Results of LS-CCC in the treatment of main bile duct stones 3.2.1 Intraoperative findings

- In 95.2 % of patients 4 trocarts were used and in only 4.8% of patients 5 trocarts were used

- 41.7% of patients with history of abdominal operations having adhesion, in which 35.7% of patients had severe adhesion

* Placement of CCC:

- Success rate: 100%

- Placement time: 5.05 ± 2.47 mins

- Bile duct injury during placement: 02 patients (2.4%)

- Channel dislodgement during stone removal: 03 patients (3.6%)

- There were no cases with stone or bile spillage into the abdominal cavity

* Stone removal results:

Observed stone clearance by cholangioscopy: 69 patients (82.1%) Observed retained stones by cholangioscopy: 15 patients (17.9%)

* Causes of retained stones observed by cholangioscopy:

Biliary strictures: 15/15 (100%) patients

* Time of stone removal:

Mean: 52.50 ± 22.84 mins

3.2.2 Early results

- Postoperative pain duration: 1.9 ± 0.53 days (1- 4 days)

- Time to return of bowel function: 2.17 ± 0.82 days (1- 4 days)