Magnetic compression anastomosis is useful in biliary anastomotic strictures after living donor liver transplantation

Endoscopic application of magnetic compression anastomosis: a review

Magnetic compression anastomosis (MCA) is a new method that provides sutureless passage construction for tubular organs. Due to the high recurrence rate of conventional endoscopic treatment and the high morbidity and mortality of surgical procedures, the MCA technique shows promise. The aim of this review is to comprehensively examine the literature related to the use of MCA in different gastrointestinal diseases over the past few years, categorizing them according to the anastomotic site and describing in detail the various methods of magnet delivery and the clinical outcomes of MCA. MCA is an innovative technique, and its use represents an advancement in the field of minimally invasive interventions. Comparison studies have shown that the anastomosis formed by MCA is comparable to or better than surgical sutures in terms of general appearance and histology. Although most of the current research has involved animal studies or studies with small populations, the safety and feasibility of MCA have been preliminarily demonstrated. Large prospective studies involving populations are still needed to guarantee the security of MCA. For technologies that have been initially used in clinical settings, effective measures should also be implemented to identify, even prevent, complications. Furthermore, specific commercial magnets must be created and optimized in this emerging area.

Magnetic compression anastomosis for the treatment of complete biliary obstruction after cholecystectomy

BACKGROUND AND AIMS

Post-cholecystectomy biliary strictures can be treated surgically or nonsurgically. Although endoscopic or percutaneous treatments are the preferred approaches, these methods are not feasible in cases in which complete stricture occlusion prevents the successful passage of a guidewire. The utility of magnetic compression anastomosis (MCA) in patients with post-cholecystectomy complete biliary obstruction that cannot be treated conventionally was evaluated.

METHODS

MCA was performed in 10 patients with post-cholecystectomy biliary strictures that did not resolve with conventional endoscopic or percutaneous treatment. One magnet was delivered through the percutaneous transhepatic biliary drainage tract, and another was advanced via ERCP of the common bile duct. After magnet approximation and recanalization, a fully covered self-expandable metal stent (FCSEMS) was placed for 3 months and then replaced for an additional 3 months. Stricture resolution was evaluated after FCSEMS removal.

RESULTS

Among the 10 patients who underwent MCA for post-cholecystectomy biliary stricture, the biliary injury was Strasberg type B in 2, type C in 3, and type E in 5. Recanalization was successful in all patients (technical success rate, 100%). The mean follow-up period after recanalization was 50.2 months (range, 13.2-116.8 months). Partial restenosis after MCA occurred in 2 patients at 24.1 and 1.6 months after stent removal. ERCP with FCSEMS placement resolved the recurrent stenosis in both patients.

CONCLUSIONS

MCA is a useful nonsurgical alternative treatment for complete biliary obstruction after cholecystectomy that cannot be resolved by use of conventional methods.

Enhanced hemocompatibility and rapid magnetic anastomosis of electrospun small-diameter artificial vascular grafts

Background: Small-diameter (<6 mm) artificial vascular grafts (AVGs) are urgently required in vessel reconstructive surgery but constrained by suboptimal hemocompatibility and the complexity of anastomotic procedures. This study introduces coaxial electrospinning and magnetic anastomosis techniques to improve graft performance. Methods: Bilayer poly(lactide-co-caprolactone) (PLCL) grafts were fabricated by coaxial electrospinning to encapsulate heparin in the inner layer for anticoagulation. Magnetic rings were embedded at both ends of the nanofiber conduit to construct a magnetic anastomosis small-diameter AVG. Material properties were characterized by micromorphology, fourier transform infrared (FTIR) spectra, mechanical tests, in vitro heparin release and hemocompatibility. In vivo performance was evaluated in a rabbit model of inferior vena cava replacement. Results: Coaxial electrospinning produced PLCL/heparin grafts with sustained heparin release, lower platelet adhesion, prolonged clotting times, higher Young's modulus and tensile strength versus PLCL grafts. Magnetic anastomosis was significantly faster than suturing (3.65 ± 0.83 vs. 20.32 ± 3.45 min, p < 0.001) and with higher success rate (100% vs. 80%). Furthermore, magnetic AVG had higher short-term patency (2 days: 100% vs. 60%; 7 days: 40% vs. 0%) but similar long-term occlusion as sutured grafts. Conclusion: Coaxial electrospinning improved hemocompatibility and magnetic anastomosis enhanced implantability of small-diameter AVG. Short-term patency was excellent, but further optimization of anticoagulation is needed for long-term patency. This combinatorial approach holds promise for vascular graft engineering.

Role of ERCP in Benign Biliary Strictures

Benign biliary strictures (BBS) can be associated with several causes, with postoperative and inflammatory strictures representing the most common ones. Endoscopy represents nowadays the first-line treatment in the management of BBS. Endoscopic balloon dilatation, plastic stents placement, fully covered metal stent placement, and magnetic compression anastomosis are the endoscopic techniques available for the treatment of BBS. The aim of this study is to perform a review of the literature to assess the role of endoscopy in the management of BBS and to evaluate the application of the different procedures in the different clinical settings.

Percutaneous Management of Benign Biliary Strictures

Benign biliary strictures are often due to a variety of etiologies, most of which are iatrogenic. Clinical presentation can vary from asymptomatic disease with elevated liver enzymes to obstructive jaundice and recurrent cholangitis. Diagnostic imaging methods, such as ultrasound, multidetector computed tomography, and magnetic resonance imaging (cholangiopancreatography), are used to identify stricture location, extent, and possible source of biliary obstruction. The management of benign biliary strictures requires a multidisciplinary team approach and include endoscopic, percutaneous, and surgical interventions. Percutaneous biliary interventions provide an alternative diagnostic and therapeutic approach, especially in patients who are not amenable to endoscopic evaluation. This review provides an overview of benign biliary strictures and percutaneous management by interventional radiologists. Diagnostic evaluation with percutaneous transhepatic cholangiography and treatment options, including biliary drainage, balloon dilation, retrievable/biodegradable stents, and other innovative minimally invasive options, are discussed.

Magnetic compression anastomosis via EUS-guided hepaticogastrostomy for recanalization of complete common hepatic bile duct transection

Video 1Magnetic compression anastomosis via EUS-guided hepaticogastrostomy for recanalization of complete common hepatic bile duct transection.

Endoscopic gastrointestinal anastomosis: a review of established techniques

Technologic advancements in the field of therapeutic endoscopy have led to the development of minimally invasive techniques to create GI anastomosis without requiring surgery. Examples of the potential clinical applications include bypassing malignant and benign gastric outlet obstruction, providing access to the pancreatobiliary tree in those who have undergone Roux-en-Y gastric bypass, and relieving pancreatobiliary symptoms in afferent loop syndrome. Endoscopic GI anastomosis is less invasive and less expensive than surgical approaches, result in improved outcomes, and therefore are more appealing to patients and providers. The aim of this review is to present the evolution of luminal endoscopic gastroenteric and enteroenteric anastomosis dating back to the first compression devices and to describe the clinical techniques being used today, such as magnets, natural orifice transluminal endoscopic surgery, and EUS-guided techniques. Through continued innovation, endoscopic interventions will rise to the forefront of the therapeutic arsenal available for patients requiring GI anastomosis.

Magnetic Compression Anastomosis for the Treatment of Post-Transplant Biliary Stricture

A number of different conditions can lead to a bile duct stricture. These strictures are particularly common after biliary operations, including living-donor liver transplantation. Endoscopic and percutaneous methods have high success rates in treating benign biliary strictures. However, these conventional methods are difficult to manage when a guidewire cannot be passed through areas of severe stenosis or complete obstruction. Magnetic compression anastomosis has emerged as an alternative nonsurgical treatment method to avoid the mortality and morbidity risks of reoperation. The feasibility and safety of magnetic compression anastomosis have been reported in several experimental and clinical studies in patients with biliobiliary and bilioenteric strictures. Magnetic compression anastomosis is a minimally traumatic and highly effective procedure, and represents a new paradigm for benign biliary strictures that are difficult to treat with conventional methods.

Magnetic Anastomosis Rings to Create Portacaval Shunt in a Canine Model of Portal Hypertension

PURPOSE

This study evaluated a novel magnetic compression technique (magnamosis) for creating a portacaval shunt in a canine model of portal hypertension, relative to traditional manual suture.

METHODS

Portal hypertension was induced in 18 dogs by partial ligation of the portal vein (baseline). Six weeks later, extrahepatic portacaval shunt implantation was performed with either magnetic anastomosis rings, or traditional manual suture (n = 9, each). The two groups were compared for operative time, portal vein pressure, and serum biochemical indices. Twenty-four weeks post-implantation, the established anastomoses were evaluated by color Doppler imaging, venography, and gross and microscopic histological examinations.

RESULTS

Anastomotic leakage did not occur in either group. The operative time to complete the anastomosis for magnamosis (4.12 ± 1.04 min) was significantly less than that needed for manual suture (24.47 ± 4.89 min, P < 0.01). The portal vein pressure in the magnamosis group was more stable than that in the manual suture group. The blood ammonia level at the end of the 24-week post-implantation observation period was significantly lower in the magnamosis group than in the manual suture group. Gross and microscopic histological examinations revealed that better smoothness and continuity of the vascular intima had been achieved via magnamosis than with manual suture.

CONCLUSION

Magnamosis was superior to manual suture for the creation of a portacaval shunt in this canine model of portal hypertension.

Optimized force range of magnetic compression anastomosis in dog intestinal tissue

BACKGROUND

Magnetic compression anastomosis (MCA) is a commonly used anastomosis method. MCA was widely used in tissues repair, gastroenterostomy, choledochoenterostomy, and so on. It is safer and more effective than stapler and manual surgical suturing. However, there are few detailed studies on the biomechanical characteristics and tissue transformation mechanisms of the anastomosis process. In this research, taking intestinal tissue as research object, we need to determine an optimal compressive force range to provide a biomechanical reference for the design of anastomats.

METHODS

Magnets with different magnetic force groups (2.06, 3.21, 6.27, 13.3 and 19.2 N) were implanted into each dog to form intestinal tissue side-to-side anastomoses. Five dogs were euthanized on each of postoperative day 1, day 3, and day 7. Anastomoses were then harvested and compared with respect to postoperative complications, histology and tear-resistance load capacity (TRLC).

RESULTS

The TRLC of anastomotic tissue formed by magnets with different magnetic forces differed markedly, but with the tissue growth, the TRLC differences between groups were decreased. Histology of anastomotic tissue showed that, in the initial stage, the anastomoses compressed by 2.06-N magnets did not form effectively, while the leakage appeared in the anastomoses compressed by 19.2-N magnets, in the rest groups, with magnetic force increasing, severity of ischemia and necrosis of compressed tissue increased and healing speed of anastomotic tissue improved. In the late stage, the influence of magnetic force for anastomotic tissue was gradually diminished.

CONCLUSIONS

The magnetic force applied on the magnetic compression anastomats affects the necrosis speed of compressed tissue and the healing speed of anastomotic tissue. The optimal compressive force range for intestinal compression anastomosis is 6.27 N to 13.3 N, and the actual optimal compression pressure is 79.8 kPa - 169 kPa.

LEVEL OF EVIDENCE

Magnetic compression anastomosis (MCA) is a commonly used anastomosis method. MCA was widely used in tissues repair, gastroenterostomy, choledochoenterostomy, and so on. It is safer and more effective than stapler and manual surgical suturing. However, there are few detailed studies on the biomechanical characteristics and tissue transformation mechanisms of the anastomosis process. In this research, taking intestinal tissue as research object, we need to determine an optimal compressive force range to provide a biomechanical reference for the design of anastomats.

Novel magnetic compression technique for establishment of a canine model of tracheoesophageal fistula

BACKGROUND

Clinically, tracheoesophageal fistula (TEF) is lack of effective surgical strategies. One reason is due to the lack of appropriate animal models of acquired TEF, which is usually complex and difficult. Recently, the magnetic compression technique has been applied for digestive tract anastomosis or vascular anastomosis in animals. In this study, an animal model of TEF in dogs was developed by using the magnetic compression technique, hoping to provide a new method for mimicking TEF.

AIM

To establish a TEF model in dogs by using the magnetic compression technique.

METHODS

Six male beagles were used as models with two Nd-Fe-B permanent magnets for TEF. The parent magnet and the daughter magnet were placed in the cervical esophagus and trachea, respectively. The anterior wall of the esophagus and the posterior wall of the trachea were compressed when the two magnets coupled. After 4-6 d, the necrotic tissue between the two magnets fell off and the parent and daughter magnets disengaged from the target location, leaving a fistula. Gastroscopy/bronchoscopy, upper gastrointestinal contrast study, and histological analysis were performed.

RESULTS

The establishment of the TEF model in all six beagles was successful. The average time of magnet placement was 4.33 ± 1.11 min (range, 3-7 min). Mean time for the magnets to disengage from the target location was 4.67 ± 0.75 d (range, 4-6 d). TEFs were observed by gastroscopy/bronchoscopy and esophageal angiography. The gross anatomical structure of the esophagus and the trachea was in good condition. There was no esophageal mucosa or pseudostratified ciliated columnar epithelium at the site of the fistula according to histological analysis.

CONCLUSION

It is simple, feasible, and minimally invasive to use the magnetic compression technique for the establishment of the TEF model in dogs.

Magnetic compression anastomosis for the treatment of benign biliary strictures: a clinical study from China

BACKGROUND

Magnetic compression anastomosis (MCA) is a revolutionary minimally invasive method to perform choledochocholedochostomy in patients with benign biliary stricture (BBS). We conducted MCA for the treatment of severe BBS that could not be treated by conventional methods.

PATIENTS AND METHODS

Patients with BBSs that could not be treated using conventional treatments were included. All patients underwent percutaneous transhepatic biliary drainage (PTBD) before MCA, and underwent cholangiography via simultaneous PTBD and endoscopic retrograde cholangiopancreatography (ERCP). The MCA device consisted of a parent and a daughter magnet. The daughter magnet was delivered via the PTBD route to the proximal end of the obstruction, and the parent magnet was delivered via ERCP to the distal end of the obstruction. After recanalization, the MCA device was removed, and biliary stenting (or PTBD) was performed for at least 6 months.

RESULTS

Of the 9 patients (age 49 ± 12.9 years), 6 had undergone orthotopic liver transplantation. MCA was successful in all 9 patients. The stricture length was 3 ± 1.7 mm, and recanalization occurred after 16.3 ± 13.2 days. Multiple plastic stents (4 patients), fully covered self-expandable metallic stents (4 patients), or PTBD (1 patient) was used after recanalization. Two mild adverse events occurred (cholangitis, 1 patient; biliary bleeding, 1 patient), but were resolved with conservative treatment. Stents were retrieved after > 6 months, and no stenosis occurred during 2-66 months of stent-free follow-up.

CONCLUSION

The MCA technique is a revolutionary method for choledochocholedochostomy in patients with severe BBS unresponsive to conventional procedures.

Biomechanical and Performance Evaluation of Magnetic Elliptical-Ring Compressive Anastomoses

BACKGROUND

After magnetic compressive anastomosis, anastomat passage through the narrow channels of the digestive tract is difficult owing to the device's large volume. Such passage can lead to mechanical damage to the digestive tract or anastomat's unstable excretion time. This article presents a new magnetic compressive anastomotic approach.

METHODS

A magnetic elliptical-ring compressive anastomat was designed and evaluated for placement and passage in vitro. Nine young adult dogs underwent laparotomy with intestinal tissue side-to-side anastomosis. Four different groups of magnetic compressive anastomats of two different magnetic force levels (20 N or 30 N) and shapes (round or elliptical) were implanted into each dog simultaneously. Three dogs were euthanized on each of postoperative day 1, day 4, and day 7. Anastomoses were then compared with respect to histology and tensile fracture force.

RESULTS

The magnetic elliptical-ring compressive anastomat was functional but produced less obstruction compared to its round counterpart during passage through the esophagus and intestine. Nine dogs underwent successful surgery and harvesting of 30 total anastomoses. Histology of anastomotic tissue showed that, along the newly formed tunnel connecting the two sides of anastomotic tissues, compressed tissues became thinner and fell off, and initial anastomoses formed on the seventh postoperative day. There were large differences in tensile fracture force among the anastomoses formed by magnets with different magnetic forces of the same structure. However, the magnetic compressive anastomat structure did not affect anastomotic repair during magnetic compression anastomosis.

CONCLUSIONS

The magnetic elliptical-ring compressive anastomat is an efficient anastomotic device that can be used easily and with good passage. The device has good biomechanical properties and can be used with endoscopy to reduce operative time.

New Concept for a Thoracic Drainage System Using Magnetic Actuation

Objectives. Thoracic drainage is a common procedure to drain fluid, blood, or air from the pleural cavity. Some attempts to develop approaches to new thoracic drainage systems have been made; however, a simple tube is often currently used. The existing drain presupposes that it is placed correctly and that the tip does not require moving after insertion into the thoracic cavity. However, in some cases, the drain is not correctly placed and reinsertion of an additional drain is required, resulting in significant invasiveness to the patient. Therefore, a more effective drainage system is needed. This study aimed to develop and assess a new thoracic drain via a collaboration between medical and engineering personnel. Methods. We developed the concept of a controllable drain system using magnetic actuation. A dry laboratory trial and accompanying questionnaire assessment were performed by a group of thoracic and general surgeons. Objective mechanical measurements were obtained. Porcine experiments were also carried out. Results. In a dry laboratory trial, use of the controllable drain required significantly less time than that required by replacing the drain. The average satisfaction score of the new drainage system was 4.07 out of 5, indicating that most of the research participants were satisfied with the quality of the drain with a magnetic actuation. During the porcine experiment, the transfer of the tip of the drain was possible inside the thoracic cavity and abdominal cavity. Conclusion. This controllable thoracic drain could reduce the invasiveness for patients requiring thoracic or abdominal cavity drainage.

Endoscopic management of biliary strictures post-liver transplantation

Biliary complications play a significant role in morbidity of liver transplant recipients. Biliary strictures occur between 10%-25% of patients with a higher incidence in living donor recipients compared to deceased donors. Strictures can be classified as either anastomotic or non-anastomotic and may be related to ischemic events. Endoscopic management of biliary strictures in the post-transplant setting has become the preferred initial approach due to adequate rates of resolution of anastomotic and non-anastomotic strictures (NAS). However, several factors may increase complexity of the endoscopic approach including surgical anatomy, location, number, and severity of bile duct strictures. Many endoscopic tools are available, however, the approach to management of anastomotic and NAS has not been standardized. Multi-disciplinary techniques may be necessary to achieve optimal outcomes in select patients. We will review the risk factors associated with the development of bile duct strictures in the post-transplant setting along with the efficacy and complications of current endoscopic approaches available for the management of bile duct strictures.

Maintenance of the fistulous tract after recanalization via magnetic compression anastomosis in completely obstructed benign biliary stricture

OBJECTIVE

This study compared the efficacy of a percutaneous transhepatic cholangioscopy (PTCS) catheter and a fully covered self-expandable metal stent (FCSEMS) for maintaining biliary tract patency after magnetic compression anastomosis (MCA).

METHODS

This study included patients with completely obstructed benign biliary stricture (BBS), which was resolved by MCA and subsequent insertion of a PTCS catheter or FCSEMS. We compared the restenosis-free time after removal of the PTCS catheter or FCSEMS, and the rate of complications.

RESULTS

A total of 49 patients were analyzed. The mean ages of the patients in these groups were 50.1 and 49.6 years, respectively. The predisposing conditions causing complete BBS were liver transplantation (n = 38), abdominal surgery (n = 10) and trauma (n = 1). The mean indwelling durations were 176 and 128 days in the PTCS catheter and FCSEMS groups, respectively. The mean follow-up duration after removal of the PTCS catheter and FCSEMS were 2259 and 680.5 days, respectively. Three patients in the PTCS group and three patients in the FCSEMS group experienced stricture relapse. The mean duration between recurrence and stent removal were 924 and 265 days, respectively, and the numbers of stricture-free days did not differ significantly between the two groups. The adverse event rate did not differ significantly between the PTCS and FCSEMS groups (50% vs. 24.2%, respectively).

CONCLUSIONS

FCSEMSs have an efficacy and safety similar to those of PTCS catheters for maintaining biliary tract patency after MCA, but are more convenient for patients.

Laparoscopic Magnetic Compression Biliojejunostomy: A Preliminary Clinical Study

BACKGROUND

Magnetic compression anastomosis is a feasible and effective method for bilioenteric anastomosis (BEA) in animal model. The objective of the present study was to report our initial clinical experience in laparoscopically magnetic compression bilioenteric anastomosis (LMC-BEA).

METHODS

Patients with obstructive jaundice who were candidates for LMC-BEA were prospectively enrolled from 2013 to 2015. All the procedures were performed laparoscopically. A mother magnet and drainage tube were placed in the proximal bile duct and tightened by a purse suture after dissection of the common bile duct. The drainage tube was introduced into the jejunal lumen at the anastomotic site and guided a daughter magnet to approximate the mother magnet. The two magnets mated at the anastomotic site. All the patients were routinely followed up for magnets discharge till the end of the study.

RESULTS

In total, four patients with malignant obstructive jaundice and one patient with benign biliary stricture were included. The median age was 70 y (range, 49-74 y). The median time for LMC-BEA was 12 min (range, 8-15 min). A complete anastomosis was confirmed after a median time of 21 d (range, 5-25 d) postoperatively by cholangiography via drainage tube. The magnets were expulsed around 41 d after surgery (range, 12-47 d) postoperatively. With a median follow-up of 313 d (range, 223-1042 d), no complications associated with magnetic anastomosis was documented, such as bile leakage or anastomotic stricture.

CONCLUSIONS

Magnetic compression is a promising alternate method for laparoscopic BEA. Among the five patients undergoing LMC-BEA, no one developed anastomotic complications.

Metal, magnet or transplant: options in primary sclerosing cholangitis with stricture

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease of the biliary tree of unknown etiology leading to stricturing and dilation. There is currently no effective medical therapy for PSC and liver transplantation (LT) remains the ultimate treatment for severe disease defined as repeated episodes of cholangitis, decompensated biliary cirrhosis or in exceptional cases, cholangiocarcinoma (CCA). Patients often present with a "dominant" stricture and the therapeutic endoscopist plays an important role in management to improve biliary patency using a variety of techniques that involve sampling, balloon dilation and temporary stenting. Newer modalities such as self-expanding metal stents or magnetic compression anastomosis that have been used in other diseases may have a role to play in PSC but should remain investigational. Liver transplantation for PSC is curative in most cases but the optimal timing remains unclear. The lifetime risk of CCA is 10-15% in PSC patients and LT is often not possible at the time of diagnosis. Multiple studies have tried to identify risk factors and to diagnose CCA at an early stage when surgical resection may be possible or LT can be performed. However, deceased donor organs for LT remain in short supply throughout the world so even identifying PSC patients with CCA at an early stage may not be beneficial unless a live donor organ is available.

Magnetic compression anastomosis for the complete dehiscence of hepaticojejunostomy in a patient after living-donor liver transplantation

Background

Magnetic compression anastomosis (MCA) is a minimally invasive method of anastomosis that does not involve a surgical procedure in patients with stricture, obstruction, or dehiscence of anastomosis after surgery. We experienced a case of complete dehiscence of bilioenteric anastomosis that was successfully treated by MCA.

Case presentation

A 55-year-old woman received ABO-incompatible right-lobe living-donor liver transplantation with hepaticojejunostomy for the right anterior duct (RAD) and right posterior duct (RPD). Nineteen days after the operation, bilious and bloody discharge was detected from the abdominal drain. We performed an emergency operation and found that the anastomosis was completely dehiscent. We placed bile drainage catheters into the stumps of the RAD and RPD. She repeatedly experienced cholangitis after the surgery, so we added percutaneous transhepatic cholangial drainage (PTCD) tubes. We decided to treat the complete dehiscence of anastomosis by MCA. One year after the liver transplantation, we performed MCA for the RAD. The bilioenteric fistula was completed 21 days after MCA, and the magnets were retrieved by double-balloon endoscopy. Two months later, MCA for the RPD was also performed by the same procedure. The bilioenteric fistula was not completely established, so we performed double-balloon endoscopy and pulled the magnets down 47 days after MCA for the RAD. The internal/external bile drainage tubes were then left in place to maintain the bilioenteric fistula. Twelve months after MCA for the RAD and 19 months after MCA for the RPD, we removed the tubes without any complications.

Conclusion

Magnetic compression anastomosis for stricture, obstruction, or dehiscence of the anastomosis after living-donor liver transplantation was an effective and safe procedure.

Magnetic Compression Stricturoplasty For Treatment of Refractory Esophageal Strictures in Children: Technique and Lessons Learned

INTRODUCTION

Esophageal stricture is the most common complication following repair of esophageal atresia (EA). In general, these strictures are successfully managed using endoscopic techniques including bougie and balloon dilation, stenting, and chemotherapeutic agent application. If these techniques are unsuccessful, patients require segmental esophageal resection and reanastomosis or esophageal replacement. Magnetic compression anastomosis has been described in children. Herein we report our experience with magnetic compression stricturoplasty to treat refractory strictures after EA repair.

METHODS

We reviewed our experience using magnets to treat refractory strictures in 2 patients. Both patients failed multiple standard interventions. Because of near complete esophageal obstruction, both patients were candidates for esophageal replacement or segmental resection/anastamosis. In both patients, we applied neodymium-iron-boron magnets using fluoroscopic and endoscopic guidance.

RESULTS

The magnets were successfully positioned in both cases. Magnets were left in place for 7 and 10 days allowing for gradual compression stricturoplasty/anastamosis. Upon removal of the magnets, recanalization was visualized endoscopically and self-expanding stents were placed. There were no leaks or significant early complications. By 31 months post-magnetic stricturoplasty, both patients achieved durable esophageal patency without dysphagia.

CONCLUSION

Magnetic stricturoplasty was successful at establishing early patency of the esophagus in 2 patients with recalcitrant EA strictures. Fundamental knowledge of magnetism was critical in configuring magnet arrays for surgery. In both cases, early follow-up is promising. Further follow-up will define the long-term success of this technique.

Biliary-duodenal anastomosis using magnetic compression following massive resection of small intestine due to strangulated ileus after living donor liver transplantation: a case report

Background

Despite the improvements of surgical techniques and postoperative management of patients with liver transplantation, biliary complications are one of the most common and important adverse events. We present a first case of choledochoduodenostomy using magnetic compression following a massive resection of the small intestine due to strangulated ileus after living donor liver transplantation.

Case presentation

The 54-year-old female patient had end-stage liver disease, secondary to liver cirrhosis, due to primary sclerosing cholangitis with ulcerative colitis. Five years earlier, she had received living donor liver transplantation using a left lobe graft, with resection of the extrahepatic bile duct and Roux-en-Y anastomosis. The patient experienced sudden onset of intense abdominal pain. An emergency surgery was performed, and the diagnosis was confirmed as strangulated ileus due to twisting of the mesentery. Resection of the massive small intestine, including choledochojejunostomy, was performed. Only 70 cm of the small intestine remained. She was transferred to our hospital with an external drainage tube from the biliary cavity and jejunostomy. We initiated total parenteral nutrition, and percutaneous transhepatic biliary drainage was established to treat the cholangitis. Computed tomography revealed that the biliary duct was close to the duodenum; hence, we planned magnetic compression anastomosis of the biliary duct and the duodenum. The daughter magnet was placed in the biliary drainage tube, and the parent magnet was positioned in the bulbus duodeni using a fiberscope. Anastomosis between the left hepatic duct and the duodenum was accomplished after 25 days, and the biliary drainage stent was placed over the anastomosis to prevent re-stenosis. Contributions to the successful withdrawal of parenteral nutrition were closure of the ileostomy in the adaptive period, preservation of the ileocecal valve, internal drainage of bile, and side-to-side anastomosis.

Conclusions

Choledochoduodenostomy with magnet compression could be a less invasive and safer method for treatment of biliary stricture that cannot be accessed by conventional surgery.

Treatment of completely obstructed benign biliary strictures with magnetic compression anastomosis: follow-up results after recanalization

BACKGROUND AND AIMS

Although nonsurgical methods produce high clinical success rates in the treatment of benign biliary stricture (BBS), conventional methods are not always successful in cases of severe biliary stricture or complete obstruction. Therefore, the efficacy of magnetic compression anastomosis (MCA) for treatment of refractory BBS was evaluated in a single-center, nonrandomized study.

METHODS

MCA was performed in patients with BBS that was not resolved by conventional endoscopic or percutaneous treatments. One magnet was delivered through the percutaneous transhepatic biliary drainage tract, and the other advanced through 1 of 3 different routes. After magnet approximation and recanalization, an internal drainage catheter was placed for 6 months.

RESULTS

This study followed 39 patients who underwent MCA after the development of postoperative or traumatic strictures. Recanalization was achieved successfully in 35 patients. There was an acceptable procedure-related adverse event of mild cholangitis in 1 patient and no procedure-related mortalities. The average elapsed time from magnet approximation to removal was 57.4 days (range, 13-182 days), and the mean follow-up period after recanalization was 41.9 months (range, 7.1-73.4 months). Restenosis after MCA recurred in 1 patient, and partial restenosis occurred in another patient, but recanalization in these patients was successful using a guidewire via the percutaneous and endoscopic tracts.

CONCLUSIONS

MCA represents an alternative nonsurgical recanalization method for BBSs that cannot be treated by conventional methods. The rate of stricture recurrence after MCA was lower than that after conventional methods, likely because of the creation of a new fistula tract instead of dilation of a previous stricture.

An Update on Endoscopic Management of Post-Liver Transplant Biliary Complications

Biliary complications are the most common post-liver transplant (LT) complications with an incidence of 15%-45%. Furthermore, such complications are reported more frequently in patients who undergo a living-donor LT compared to a deceased-donor LT. Most post-LT biliary complications involve biliary strictures, bile leakage, and biliary stones, although many rarer events, such as hemobilia and foreign bodies, contribute to a long list of related conditions. Endoscopic treatment of post-LT biliary complications has evolved rapidly, with new and effective tools improving both outcomes and success rates; in fact, the latter now consistently reach up to 80%. In this regard, conventional endoscopic retrograde cholangiopancreatography remains the preferred initial treatment. However, percutaneous transhepatic cholangioscopy is now central to the management of endoscopy-resistant cases involving complex hilar or multiple strictures with associated stones. Many additional endoscopic tools and techniques-such as the rendezvous method, magnetic compression anastomosis , and peroral cholangioscopy-combined with modified biliary stents have significantly improved the success rate of endoscopic management. Here, we review the current status of endoscopic treatment of post-LT biliary complications and discuss conventional as well as the aforementioned new tools and techniques.

A novel technique for the endoscopic treatment of complete biliary anastomosis obstructions after liver transplantation: through-the-scope magnetic compression anastomosis

BACKGROUND AND AIMS

Magnetic compression anastomosis is a rescue technique for recanalization of complete biliary strictures. Here, we present magnetic compression anastomosis with novel through-the-scope magnets in patients with complete duct-to-duct anastomosis obstruction after liver transplantation.

METHODS

The magnets were 2 and 2.4 mm in diameter, with a hole at the center for inserting a guidewire. One of the magnets was advanced through the scope up to the distal site of the stricture by using a 7F pusher. The other magnet was pushed percutaneously through the 10F sheath. The procedure was terminated when the magnets were approximated or properly aligned. Recanalization was followed by percutaneous cholangiography. Patients underwent multiple plastic stenting after recanalization was achieved.

RESULTS

Nine patients with a stricture length of less than 1 cm, a stump in the donor bile ducts close to the stricture, and proper positioning of the bile duct stumps, underwent magnetic compression anastomosis. Seven patients had a live donor-related liver transplantation. The mean stricture time was 24.1 ± 17.1 months. The mean stricture length was 4.0 ± 1.2 mm. Recanalization was achieved in 7 patients (77%) after a mean recanalization time of 8.1 ± 4.7 days. There was no recurrence after 4.8 ± 3.8 months of stent-free follow-up. No adverse events were observed.

CONCLUSIONS

The through-the-scope magnet procedure was effective in the recanalization of complete anastomotic biliary obstructions after liver transplantation in a selected group of patients with a short stricture length and an appropriate anatomy.

Surgical Endoscopy Versus Endoscopic Surgery for Obesity

BACKGROUND

Obesity treatment options are of great interest worldwide with major developments in the past 20 years. From general surgery to natural orifice transluminal endoscopic surgery intervention nowadays, obesity surgical therapies have surely developed and are now offering a variety of possibilities.

AREAS OF UNCERTAINTY

Although surgery is the only proven approach for weight loss, a joint decision between the physician and patient is required before proceeding to such a procedure. With a lot of options available, the treatment should be individualized because the benefits of surgical intervention must be weighed against the surgical risks.

DATA SOURCES

Medline search to locate full-text articles and abstracts with obvious conclusions by using the keywords: obesity, surgical endoscopy, gastric bypass, bariatric surgery, and endoscopic surgery, alone and in various combinations. Additional relevant publications were also searched using the reference lists of the identified articles as a starting point.

RESULTS

Laparoscopic Roux-en-Y gastric bypass still is the most effective, less invasive, bariatric surgical intervention, although there are various complications encountered, such as postoperative hemorrhage (1.9%-4.4%), internal hernias, anastomotic strictures (2.9%-23%), marginal ulcerations (1%-16%), fistulas (1.5%-6%), weight gain, and nutritional deficiencies. However, the absence of parietal incisions, less pain, decreased risk of infection, and short hospital stay make room for endoscopic surgery as a possible valid option for obesity for both the doctors' and the patients' perspective.

CONCLUSIONS

The current tendency is to promote surgical treatment of obesity to a status of less invasive scars therefore promoting minimally invasive surgical techniques.

Percutaneous Transhepatic Cholangioscopy in Bilioenteric Anastomosis Stricture

Bilioenteric anastomosis strictures are a serious complication of biliary surgery, and often result in recurrent cholangitis, choledocholithiasis, biliary cirrhosis, and hepatic failure. Bilioenteric reconstructive surgery is the standard treatment of choice for such complications. However, percutaneous transhepatic cholangioscopy (PTCS), also known as per-oral endoscopic-guided intervention, is a less invasive procedure that is becoming an increasingly popular alternative. This review describes the PTCS procedure (including the preparation process), as well as the diagnostic and therapeutic role of PTCS in bilioenteric anastomosis strictures.

Percutaneous transhepatic cholangioscopy for biliary complications after liver transplantation: a single center experience

BACKGROUND

Some biliary complications after liver transplantation (LT) are difficult to manage by endoscopic or radiologic intervention alone. In these cases, percutaneous transhepatic cholangioscopy (PTCS) can be used as an adjuvant option.

METHODS

Patients who underwent PTCS for post-LT biliary complications between August 1992 and January 2016 were retrospectively reviewed.

RESULTS

Fifteen patients underwent PTCS for post-LT biliary complications. The median age at LT was 47 years and 11 patients were male. Indications for LT were as follows: decompensated liver cirrhosis (n = 9), hepatocellular carcinoma (n = 5), and acute fulminant liver failure (n = 1). Single living donor was common (n = 11) and duct-to-duct anastomosis was performed in 11 patients. The median age at PTCS was 52 years and indications for PTCS were as follows: intrahepatic duct stone (n = 10), common bile duct stone (n = 1), biliary cast (n = 1), and biliary stricture (n = 3). There were no significant PTCS-related morbidity and mortality. However, four patients (26.7%) needed additional radiologic intervention (n = 2) or surgery (n = 2) after PTCS.

CONCLUSIONS

Percutaneous transhepatic cholangioscopy in conjunction with endoscopic and radiologic interventions can aid in managing post-LT biliary complications and avoiding reoperation.

Advances in endoscopic management of biliary complications after living donor liver transplantation: Comprehensive review of the literature

Apart from noticeable improvements in surgical techniques and immunosuppressive agents, biliary complications remain the major causes of morbidity and mortality after living donor liver transplantation (LDLT). Bile leakage and stricture are the predominant complications. The reported incidence of biliary complications is 15%-40%, and these are known to occur more frequently in living donors than in deceased donors. Despite the absence of a confirmed therapeutic algorithm, many approaches have been used for treatment, including surgical, endoscopic, and percutaneous transhepatic techniques. In recent years, nonsurgical approaches have largely replaced reoperation. Among these, the endoscopic approach is currently the preferred initial treatment for patients who undergo duct-to-duct biliary reconstruction. Previously, endoscopic management was achieved most optimally through balloon dilatation and single or multiple stents placement. Recently, there have been significant developments in endoscopic devices, such as novel biliary stents, as well as advances in endoscopic technologies, including deep enteroscopy, the rendezvous technique, magnetic compression anastomosis, and direct cholangioscopy. These developments have resulted in almost all patients being managed by the endoscopic approach. Multiple recent publications suggest superior long-term results, with overall success rates ranging from 58% to 75%. This article summarizes the advances in endoscopic management of patients with biliary complications after LDLT.

Management issues in post living donor liver transplant biliary strictures

Biliary complications are common after living donor liver transplant (LDLT) although with advancements in surgical understanding and techniques, the incidence is decreasing. Biliary strictures are more common than leaks. Endoscopic retrograde cholangiopancreatography (ERCP) is the first line modality of treatment of post LDLT biliary strictures with a technical success rate of 75%-80%. Most of ERCP failures are successfully treated by percutaneous transhepatic biliary drainage (PTBD) and rendezvous technique. A minority of patients may require surgical correction. ERCP for these strictures is technically more challenging than routine as well post deceased donor strictures. Biliary strictures may increase the morbidity of a liver transplant recipient, but the mortality is similar to those with or without strictures. Post transplant strictures are short segment and soft, requiring only a few session of ERCP before complete dilatation. Long-term outcome of patients with biliary stricture is similar to those without stricture. With the introduction of new generation cholangioscopes, ERCP success rate may increase, obviating the need for PTBD and surgery in these patients.

Biliary complications after liver transplantation

Biliary complications (BCs) remain one of the most outstanding factors influencing long-term results after orthotopic liver transplantation. The authors carried out a systematic overview of 1720 papers since 2008, and focused on 45 relevant ones. Among 14,411 transplanted patients the incidence of BCs was 23%. Biliary leakage occurred in 8.5%, biliary stricture in 14.7%, mortality rate was 1-3%.

RISK FACTORS

preoperative sodium level; p = 0.037, model of end-stage liver disease score >25; p = 0.048, primary sclerosing cholangitis; p = 0.001, malignancy; p = 0.026, donor age >60, macrovesicular graft steatosis; p = 0.001, duct-to-duct anastomosis; p = 0.004, long anhepatic phase; p = 0.04, cold ischemic time >12 h; p = 0.043, use of T-tube; p = 0.032, insufficient flush of bile ducts; p = 0.001, acute rejection; p = 0.003, cytomegalovirus infection; p = 0.004 and hepatic artery thrombosis; p = 0.001. The management was surgical in case of biliary leakage, and interventional radiology or endoscopic retrograde cholangiopancreatography in case of biliary stricture. Mapping of miRNA profile is a new field of research. Nemes-Doros score is a useful tool in the estimation of hepatic artery thrombosis. Management of BCs requires a multidisciplinary expert team.

Magnetic compression anastomosis for treatment of benign biliary stricture

Endoscopic and percutaneous procedures have shown high success rates when used to treat benign biliary stricture. However, cases in which a guidewire cannot be passed through a refractory stricture or a complete obstruction are difficult to treat using conventional methods. Magnetic compression anastomosis (MCA) has emerged as a non-surgical alternative avoiding operational mortality and morbidity. The feasibility and safety of MCA have been experimentally and clinically verified in cases of biliobiliary and bilioenteric anastomosis. However, no pre-MCA assessment modality capable of predicting outcomes is as yet available, and no universally effective magnet delivery method has as yet been established, rendering it difficult to identify patients for whom MCA is appropriate. Various experimental studies seeking to overcome these limitations are underway. Such work will improve our in-depth understanding of MCA, which has been trialed in various fields. Upon further development, MCA may become a ground-breaking option for treatment of benign strictures that are difficult to resolve using conventional methods, and MCA may be expected to be minimally traumatic and highly effective. The aim of the present study was to discuss the current status of MCA and the direction of MCA development by reviewing clinical and experimental MCA data.

Magnamosis: a novel technique for the management of rectal atresia

We report a case of rectal atresia treated using magnets to create a rectal anastomosis. This minimally invasive technique is straightforward and effective for the treatment of rectal atresia in children.

Magnamosis combined with endoscopy: A new endoscopic technique in digestive surgery

Conventional hand-sewn technique is the basic method for anastomosis in the gastrointestinal tract. However, with the rapid development of minimally invasive surgery and the spread of fast track surgery, hand-sewn technique cannot satisfy the requirements of modern surgery. The common goal that the majority of surgeons seek to achieve has changed: to reduce surgical invasion and operative time as minimally as possible, on the premise that therapeutic and anastomotic effects can be guaranteed. Therefore, after more than 30 years of exploration and development, magnamosis as a novel anastomosis technique shows its significant superiority in anastomosis or recanalization in the gastrointestinal tract. Furthermore, the combination of magnamosis and endoscopy may transform part of the surgical procedures into endoscopic procedures. This review aims to elucidate the application and future development of magnamosis combined with endoscopy in anastomosis or recanalization in the gastrointestinal tract.

Magnetic gastrointestinal anastomosis in pediatric patients

BACKGROUND/PURPOSE

To describe 17 patients who underwent magnetic, non-surgical gastrointestinal (GI) anastomoses.

METHODS

Patients with GI obstruction, stenosis, or atresia were treated with image-guided and/or endoscopically placed discoid magnet pairs or catheter-based bullet-shaped magnet pairs.

RESULTS

Anastomosis was achieved in 7 days in an 11-year-old with gastric outlet obstruction due to metastatic colon cancer. Anastomosis was achieved in 8 and 10 days in 2 patients (age 2.0 years and 3.4 years) who had rectocolonic stenosis. Re-anastomosis was achieved in an average of 6 days (range 3 to 7 days) in 5 patients (age 6 months to 5.9 years) with severe recurrent postsurgical esophageal stenosis refractory to dilatation. Primary esophageal anastomosis was achieved in an average of 4.2 days (range 3 to 6 days) in 9 patients with esophageal atresia (Type A or Type C surgically converted to Type A) with a gap length of 4 cm or less. The average age of these esophageal atresia patients was 3 months (range 23 days to 5 months).

CONCLUSION

Minimally invasive magnet placement was feasible and achieved anastomosis in all patients.

Section 11. Radiological intervention approaches to biliary complications after living donor liver transplantation

Although endoscopic treatment has become the first choice to treat biliary complications, percutaneous transhepatic treatment still has important roles to treat biliary stricture or leak after living donor liver transplantation. This study reviewed a total of 527 recipients who had undergone percutaneous transhepatic treatment to treat biliary stricture (n=498) and leaks (n=29). Percutaneous transhepatic treatment included percutaneous transhepatic biliary drainage, perihepatic biloma drainage, balloon dilation of biliary stricture, and drainage catheter interposition or retrievable covered stent placement across a stricture or leak segment. Clinical success was achieved in 440 (88.4%) recipients with biliary stricture and 19 (65.5%) recipients with bile leaks. Percutaneous transhepatic treatment seems to be an effective alternative for treating biliary complications resistant to or inaccessible by endoscopic treatment.

Section 10. Endoscopic management of biliary complications in adult living donor liver transplantation

Living donor liver transplantation (LDLT) has become an accepted therapeutic option for patients with end-stage liver disease. However, biliary complications remain the major causes of morbidity and mortality for LDLT recipients. Although there are currently no reports of a clear therapeutic algorithm, many approaches have been developed to treat biliary complications, including surgical, endoscopic, and percutaneous transhepatic techniques. Endoscopic treatment is currently the preferred initial treatment for patients that have previously undergone duct-to-duct biliary reconstruction. This article discusses aspects of endoscopic management of biliary complications that occur in adult LDLT.

Magnetic compression in gastrointestinal and bilioenteric anastomosis: how much force?

AIM

The concept of compression alimentary anastomosis is well established. Recently, magnetic axial alignment pressures have been encompassed within such device constructs. We quantify the magnetic compression force and pressure required to successfully achieve gastrointestinal and bilioenteric anastomosis by in-depth interrogation of the reported literature.

METHODS

Reports of successful deployment and proof of anastomotic patency on survival were scrutinized to quantify the necessary dimensions and strengths of magnetic devices in (a) gastroenteral anastomosis in live porcine models and (b) bilioenteric anastomosis in the clinical setting. Using a calculatory tool developed for this work (magnetic force determination algorithm, MAGDA), ideal magnetic force and compression pressure were quantified from successful reports with regard to their variance by intermagnet separation.

RESULTS

Optimized ranges for both compression force and pressure were determined for successful porcine gastroenteral and clinical bilioenteric anastomoses. For gastroenteral anastomoses (porcine investigations), an optimized compression force between 2.55 and 3.57 kg at 2-mm intermagnet separation is recommended. The associated compression pressure should not exceed 60 N/cm(2). Successful bilioenteric anastomoses is best clinically achieved with intermagnet compression of 18 to 31 g and associated pressures between 1 and 3.5 N/mm(2) (at 2-mm intermagnet separation).

CONCLUSION

The creation of magnetic compression anastomoses using permanent magnets demonstrates a remarkable resilience to variations in magnetic force and pressure exertion. However, inappropriate selection of compression characteristics and magnet dimensions may incur difficulties. Recommendations of this work and the availability of the free online tool (http://magda.ucc.ie/) may facilitate a factor of robustness in the design and refinement of future devices.

EUS-guided anastomosis

Although some technical challenges in the development of dedicated devices need to be overcome, endoscopic ultrasonography (EUS)-guided anastomosis is promising as a minimally invasive technique for pancreatobiliary diseases.