A pig model for advanced laparoscopic biliary procedures

Towards a model of biliary atresia - Pilot feasibility study in newborn piglets

Biliary atresia (BA) is a rare congenital liver disease with unknown etiology, and it is the most common indication for liver transplantation in children. As BA infants suffer from intestinal malabsorption and neurodevelopmental deficits, it is necessary to identify optimal medical and nutritional strategies using appropriate neonatal animal models. We aim to determine the feasibility of using newborn piglets with surgically induced cholestasis (bile duct ligation (BDL)) to mimic clinical features of BA. Six piglets were subjected to abdominal surgery on day 4 after birth. The bile ducts were ligated, and the piglet were followed for up to 12 days. On day 12 the piglets were subjected to a hepatobiliary scintigraphy using the tracer radiolabeled Technetium(99m-tc)-mebrofenin, and blood samples were collected for biochemical profiling. Of the six piglets, hepatobiliary scintigraphy verified that two piglets (BDL) had no excretion of bile into the duodenum, i.e. full cholestasis with a hepatic extraction fraction of 84-87% and clearance time of 230-318 min. One piglet (SHAM) had bile excretion to the duodenum. In accordance with this, the BDL piglets had steatorrhea, and increased levels of bilirubin and gammaglutamyl transferase (GGT). The last three piglets were euthanized due to bile leakage or poor growth. Surgically induced cholestasis in young piglets, may offer an animal model that displays clinical characteristics of biliary atresia, including malabsorption, hyperbilirubinaemia, increased GGT and reduced hepatic excretory function. Following refinement, this animal model may be used to optimize feeding strategies to secure optimal nutrition and neurodevelopment for neonatal cholestasis/BA patients.

Efficacy of a Novel Cholangiogram Simulator for Training Laparoscopic Intraoperative Cholangiography

OBJECTIVE

Determine the efficacy of a novel low-cost, reusable simulator for training fundamental skills associated with safe and effective intraoperative cholangiography (IOC).

DESIGN

The simulator uses a balloon and retention suture tubing (representing the gallbladder, cystic duct, common bile duct, and common hepatic duct) attached to a piece of wood and placed in a laparoscopic trainer (representing the abdominal cavity) covered by a piece of simulated skin to obscure it. Following a tutorial on performing a simulated IOC using this, simulation participants independently completed a video-recorded simulated IOC and a post-training survey about the appearance and perceived usefulness of the IOC simulator as a training tool. Two experienced surgeons assessed participants' IOC performance using an IOC procedural checklist developed for this purpose. Procedural time (in seconds) was recorded and used as an additional measure of performance.

SETTING

The OhioHealth Learning Center simulation facility in the Department of Surgery at Riverside Methodist Hospital, a large tertiary care independent medical center that is part of the OhioHealth care system.

PARTICIPANTS

Eleven attending surgeons and 16 general surgery residents of different levels participated in the simulation. Two experienced surgeons assessed participants' IOC performance. One participated in the simulation along with the other 10 surgeons; the other did not.

RESULTS

High-experience participants completed more steps and spent less time than low-experience individuals; however, differences were not statistically significant. There was substantial agreement between the 2 observers regarding participants' performance. Participants scored the simulator as realistic and useful in teaching relevant steps associated with IOC.

CONCLUSIONS

Despite differences between high- and low-experience participants in steps completed and time spent, these results did not prove statistically significant. Additional studies to increase sample size are warranted to determine if significant differences exist. However, participants did generally find the simulator to be an effective training tool.

In vivo porcine training model of laparoscopic common bile duct repair with T-tube insertion under the situation of iatrogenic common bile duct injury

Purpose

We introduce a training porcine model for laparoscopic common bile duct (CBD) repair with T-tube insertion. The model could be the feasible training tool for a surgeon learning hepatobiliary surgery.

Methods

Totally laparoscopic CBD repair with T-tube insertion was performed on 9 pigs by 9 trainees naïve in hepatobiliary surgery. Similar to the situation of iatrogenic injury, CBD was transected by laparoscopic scissors at the middle part about 1 cm in length, and the transected CBD was repaired through end-to-end anastomosis with T-tube insertion. A secureness of anastomosis was confirmed by saline leakage test and all animals were sacrificed after the surgery.

Results

All novice surgeons completed operations successfully without complications. Total mean operative time was 85 ± 1.7 minutes and the mean time spent performing the CBD repair with T-tube insertion was 71 ± 3 minutes. There was no bile leakage after primary anastomosis in all animals.

Conclusion

This porcine training model for laparoscopic CBD repair with T-tube insertion could be a feasible and effective training tool for surgeons with little experience in laparoscopic hepatobiliary surgery.

Development of a training model for laparoscopic common bile duct exploration

A simple, low-cost model is described that allows for accurate reproduction of the main steps in performing laparoscopic common bile duct exploration.

Background:

Training and experience of the surgical team are fundamental for the safety and success of complex surgical procedures, such as laparoscopic common bile duct exploration.

Methods:

We describe an inert, simple, very low-cost, and readily available training model. Created using a “black box” and basic medical and surgical material, it allows training in the fundamental steps necessary for laparoscopic biliary tract surgery, namely, (1) intraoperative cholangiography, (2) transcystic exploration, and (3) laparoscopic choledochotomy, and t-tube insertion.

Results:

The proposed model has allowed for the development of the skills necessary for partaking in said procedures, contributing to its development and diminishing surgery time as the trainee advances down the learning curve. Further studies are directed towards objectively determining the impact of the model on skill acquisition.

Conclusion:

The described model is simple and readily available allowing for accurate reproduction of the main steps and maneuvers that take place during laparoscopic common bile duct exploration, with the purpose of reducing failure and complications.

Learning the surgical craft: a review of skills training options

Surgical practice is undergoing fundamental changes, and this is having a significant effect on the training of surgeons. Learning the craft of surgery is threatened by reduced elective operative exposure and general service cuts within public teaching hospitals, safer working hour legislation and pressures to accelerate the training of young surgeons. Rapid technological changes mean that 'old dogs' have to teach 'young dogs' many new tricks in a relatively adverse environment. This review outlines the great variety of resources available for skills-based training outside the operating room. These resources are ready to be used as a necessary adjunct to the training of competent surgeons in Australasia.

Comparison of laparoscopic choledochotomy closure techniques

BACKGROUND

Laparoscopic common bile duct exploration (CBDE) has traditionally been accompanied by T-tube drainage. However, other methods of choledochotomy closures have been reported. This study compared three laparoscopic methods of choledochotomy closure in a prospective, randomized fashion to determine which method should be the preferred technique.

METHODS

In this porcine model, 24 animals initially underwent laparoscopic common bile duct (CBD) clipping to simulate an obstruction. Two days later, the animals underwent laparoscopic clip removal and simulated CBDE through a 1.5-cm choledochotomy. The animals were then randomized to one of three groups: primary choledochotomy closure (group I), antegrade CBD stenting with primary closure (group II), or T-tube placement (group III). To assess for CBD stenoses and leaks, the animals were killed 2 months postoperatively, at which time a cholangiogram was performed and the bile duct harvested. The ratio of proximal CBD to choledochotomy site was assessed radiographically and histologically.

RESULTS

The operative time was significantly longer in group III (200 +/- 13 min, p < 0.05) than in group I (141 +/- 17 min) and group II (154 +/- 16 min). The ratio of the proximal CBD diameter to the choledochotomy site diameter by cholangiogram was 2.1:1.0 in group I, to 1.2:1.0 in group II, and 1.1:1.0 in group III (p < 0.01). The ratio of the proximal CBD intraluminal area to the choledochotomy site intraluminal area was 2.1:1.0 in group I compared to 1.1:1.0 in groups II and III (p < 0.01). None of the animals developed jaundice or sepsis.

CONCLUSION

Significant stenoses were present at the choledochotomy site in the primary closure group, and T-tube placement resulted in prolonged operative times. We conclude that laparoscopic antegrade CBD stenting with primary closure of the choledochotomy site is the preferred technique after choledochotomy in an animal model. Further assessment in a clinical trial is warranted.

Endoscopic approach for carotid artery surgery

BACKGROUND

Although recent advances in the treatment of carotid artery stenosis have included endovascular angioplasty and stent placement, carotid endarterectomy is still the approach of choice for carotid disease and is one of the most commonly performed operations today. Minimally invasive surgeries involving the neck have recently been performed for thyroid and parathyroid diseases. The purpose of this study was to evaluate the feasibility of an endoscopic approach for carotid artery surgery in a large animal model.

METHODS

Eight 25- to 30-kg pigs were used. Animals underwent endoscopic carotid dissection with carbon dioxide insufflation at 10 mmHg. A 1.5- to 2-cm arteriotomy was made in the common carotid artery. Four animals underwent direct arteriotomy closure, and four animals underwent synthetic patch graft placement using intracorporeal suturing techniques. Open examination of the operative site and carotid angiograms were performed at the end of the procedure. Operative time was recorded in the last four cases.

RESULTS

All animals tolerated the procedure well and carotid artery repair was successfully performed in all cases using a four-trocar technique. The entire extent of the cervical common and internal carotid arteries was exposed up to the cranial base. Cranial nerves and cervical structures were clearly visualized and preserved. No bleeding occurred at the end of the procedure. Carotid angiograms confirmed patent, nonstenotic vessels in all cases.

CONCLUSION

Endoscopic approach for carotid surgery is technically feasible in the porcine model. This approach may represent a valuable option for surgery of the carotid artery since it offers the advantages of minimally invasive techniques while maintaining the benefits of surgical arterial repair.

Developing a training model for laparoscopic common bile duct surgery

Because of the paucity of adequate training models for laparoscopic common bile duct exploration, a live porcine training model was developed and evaluated. This model requires preliminary laparoscopic ligation of the distal bile duct 7-14 days prior to utilization. It aids the development of skills for laparoscopic common bile duct exploration and should enhance the subsequent performance of these procedures.

Sutured or fibrin-glued laparoscopic choledochojejunostomy

Minimally invasive techniques for choledochojejunostomy offer theoretical advantages for palliating unresectable periampullary neoplasms. Fibrin glue, a biologic adhesive containing concentrated fibrinogen, may obviate suturing and promote healing without stricture formation. We examined the technical ability to perform laparoscopic choledochojejunostomy (LCJ) and the applicability of thrombin-activated fibrin glue in an animal model of biliary obstruction. Domestic pigs underwent laparoscopic cholecystectomy and ligation of the distal bile duct. Three days later, a side-to-side LCJ was performed by intracorporeal sutured anastomosis (n = 7) or using four stay sutures and homologous fibrin glue (n = 7). Control animals underwent a similar bypass via open laparotomy (n = 7). The postoperative interval to ambulation and oral intake was recorded, and serial serum liver enzymes were measured. The animals were sacrificed at 6 weeks, and tensile strength of the anastomoses was assessed by tensometry. Liver function tests returned to normal values within 7 days following all methods of choledochojejunostomy. In the fibrin glue group, three anastomotic leaks (43%) occurred in the 1st postoperative week. At 6 weeks, all other anastomoses were intact and patent by cholangiogram, but there was moderate stenosis of two open and one fibrin-glue anastomosis. The sutured LCJ, while taking approximately 1 h longer to perform (P < 0.05), resulted in similar efficacy and more rapid recovery (P < 0.05) than open biliary-enteric bypass. Fibrin-glued LCJ was performed rapidly, but had less tensile strength (P < 0.05) and often leaked in the early post-operative interval. We conclude that while there may be a role for laser-activated solders for primary anastomosis, thrombin-activated fibrinogen cannot be advocated as the primary means of creating biliary anastomoses. Using intracorporeal suturing techniques, laparoscopic choledochojejunostomy may be performed safely.