Eduardo A. Bonin

Update on the indications and use of colonic stents.

Self-expandable metal stent (SEMS) placement is a minimally invasive option for achieving acute colonic decompression in obstructed colorectal cancer. Colorectal stenting offers nonoperative, immediate, and effective colon decompression and allows bowel preparation for an elective oncologic resection. Patients who benefit the most are high-risk surgical patients and candidates for laparoscopic resection with complete obstruction, because emergency surgery can be avoided in more than 90% of patients. Colonic stent placement also offers effective palliation of malignant colonic obstruction, although it carries risks of delayed complications. When performed by experienced endoscopists, the technical success rate is high with a low procedural complication rate. Despite concerns of tumor seeding following endoscopic colorectal stent placement, no difference exists in oncologic long-term survival between patients who undergo stent placement followed by elective resection and those undergoing emergency bowel resection. Colorectal stents have also been used in selected patients with benign colonic strictures. Uncovered metal stents should be avoided in these patients, and fully covered stents are associated with high risk of migration. Patients with benign colonic stricture with acute colonic obstruction who are at high risk for emergency surgery can gain temporary relief of obstruction after SEMS placement; the stent can be removed en bloc with the colon specimen at surgery. This article reviews the techniques and indications of SEMS placement for benign and malignant colorectal obstructions.

Preoperative biliary stents in pancreatic cancer

BackgroundPancreatic cancer is a common digestive cancer with high mortality, and surgical resection is the only potential curative treatment option. Pancreatic head cancer is usually accompanied by biliary obstruction, which potentially increases surgical complications following pancreaticoduodenectomy. Thus, preoperative biliary drainage has long been advocated.MethodsA review of the literature using Medline, Embase and Cochrane databases was undertaken.ResultsEndoscopic or percutaneous biliary stent placement is technically successful in most patients. The use of routine preoperative biliary drainage in the setting of pancreatic cancer with biliary obstruction is controversial. Prospective studies have shown that complications related to preoperative biliary drainage using endoscopic placement of traditional plastic endoprostheses increase the overall morbidity compared to pancreaticoduodenectomy alone. Placement of self-expandable metal stents could reduce stent-related complication rates such as early occlusion because of prolonged patency, especially when surgery is delayed.ConclusionPancreatic cancer patients with deep jaundice and expected delay prior to curative intent surgery are potential candidates for temporary biliary drainage. Cholangitis remains a formal indication for early, urgent preoperative biliary decompression for patients with pancreatic cancer.

Utility of an endoscopic suturing system for prevention of covered luminal stent migration in the upper GI tract

Endoluminal stents are increasingly being used for management of benign conditions, such as refractory strictures, fistulas, anastomotic leaks, and perforations. However, stent migration remains problematic, particularly when there is no luminal narrowing or shelf to anchor the stent, and high migration rates of 53% to 58% have been reported in some studies. In 2 recent, small, feasibility studies, an endoscopic suturing system (OverStitch; Apollo Endosurgery, Inc, Austin, Tex) was used for anchoring selfexpandable metal stents (SEMSs) in the upper GI tract. Herein, we present the largest single-center case series on the utility of this suturing device for prevention of SEMS migration in benign conditions.

Endoscopic full-thickness biopsy of the gastric wall with defect closure by using an endoscopic suturing device: survival porcine study

BACKGROUND The pathogenesis of several common gastric motility diseases and functional GI disorders remains essentially unexplained. Gastric wall biopsies that include the muscularis propria to evaluate the enteric nervous system, interstitial cells of Cajal, and immune cells can provide important insights for our understanding of the etiology of these disorders. OBJECTIVES To determine the technical feasibility, reproducibility, and safety of performing a full-thickness gastric biopsy (FTGB) by using a submucosal endoscopy with mucosal flap (SEMF) technique; the technical feasibility, reproducibility, and safety of tissue closure by using an endoscopic suturing device; the ability to identify myenteric ganglia in resected specimens; and the long-term safety. DESIGN Single center, preclinical survival study. SETTING Animal research laboratory, developmental endoscopy unit. SUBJECTS Twelve domestic pigs. INTERVENTIONS Animals underwent an SEMF procedure with gastric muscularis propria resection. The resultant offset mucosal entry site was closed by using an endoscopic suturing device. Animals were kept alive for 2 weeks. MAIN OUTCOME MEASUREMENTS The technical feasibility, reproducibility, and safety of the procedure; the clinical course of the animals; the histological and immunochemical evaluation of the resected specimen to determine whether myenteric ganglia were present in the sample. RESULTS FTGB was performed by using the SEMF technique in all 12 animals. The offset mucosal entry site was successfully closed by using the suturing device in all animals. The mean resected tissue specimen size was 11 mm. Mean total procedure time was 61 minutes with 2 to 4 interrupted sutures placed per animal. Histology showed muscularis propria and serosa, confirming full-thickness resections in all animals. Myenteric ganglia were visualized in 11 of 12 animals. The clinical course was uneventful. Repeat endoscopy and necropsy at 2 weeks showed absence of ulceration at both the mucosal entry sites and overlying the more distal muscularis propria resection sites. There was complete healing of the serosa in all animals with minimal single-band adhesions in 5 of 12 animals. Retained sutures were present in 10 of 12 animals. LIMITATIONS Animal experiment. CONCLUSIONS FTGB by using the SEMF technique and an endoscopic suturing device is technically feasible, reproducible, and safe. Larger tissue specimens will allow improved analysis of multiple cell types.

Omentum patch substitute for facilitating endoscopic repair of GI perforations: an early laparoscopic pilot study with a foam matrix plug (with video).

BACKGROUND Endoscopic perforations are surgically repaired by using an omentum patch. Omentum substitutes may have broader applications particularly in certain sites (eg, esophagus). OBJECTIVE Evaluate a self-expandable foam matrix plug as a synthetic omentum substitute for repairing iatrogenic gastric perforations in a 4-week survival pig model. DESIGN Experimental pilot study. SETTING Laboratory. INTERVENTION A laparoscopic plug repair of a 1-cm, full-thickness, gastric perforation was carried out by using either a polyurethane foam matrix plug (FMP, 8 animals) or an omentum plug (OP, 6 animals, control group). MAIN OUTCOME MEASUREMENTS Follow-up endoscopy was carried out at 1 and 4 weeks. At necropsy, the perforation site was evaluated for adhesions and histology by using hematoxylin and eosin analysis. A portion of the implant was sent for bacterial and fungal culture. RESULTS All procedures were technically simple and successful. Thirteen animals thrived well for 4 weeks. One animal from the FMP group died 3 days postoperatively from diffuse peritonitis because of a misplaced plug. All remaining FMPs were intact at 4 weeks and colonized with mixed bacteria, except one animal presenting with FMP migration after 1 week. Histologically, the FMP group had more prominent inflammation and suppuration as compared with the OP group, all limited to its adjacent tissue. LIMITATIONS Animal study. CONCLUSION The FMP offered a technically simple and feasible option for repairing iatrogenic gastric perforations. With effective sealing, the clinical outcome is similar to that of an omentum patch repair. Migration and inadequate sealing is a concern, which can lead to peritonitis and sepsis. Further development is needed to improve FMP performance.

LAPAROSCOPIC RESECTION OF GASTROINTESTINAL STROMAL TUMORS (GIST)

Background Gastrointestinal mesenchymal or stromal tumors (GIST) are lesions originated on digestive tract walls, which are treated by surgical resection. Several laparoscopic techniques, from gastrectomies to segmental resections, have been used successfully. Aim Describe a single center experience on laparoscopic GIST resection. Method Charts of 15 operated patients were retrospectively reviewed. Thirteen had gastric lesions, of which ten were sub epithelial, ranging from 2-8 cm; and three were pure exofitic growing lesions. The remaining two patients had small bowel lesions. Surgical laparoscopic treatment consisted of two distal gastrectomies, 11 wedge gastric resections and two segmental enterectomies. Mechanical suture was used in the majority of patients except on six, which underwent resection and closure using manual absorbable sutures. There were no conversions to open technique. Results Mean operative time was 1h 29 min±92 (40-420 min). Average lenght of hospital stay was three days (2-6 days). There were no leaks, postoperative bleeding or need for reintervention. Mean postoperative follow-up was 38±17 months (6-60 months). Three patients underwent adjuvant Imatinib treatment, one for recurrence five months postoperatively and two for tumors with moderate risk for recurrence . Conclusion Laparoscopic GIST resection, not only for small lesions but also for tumors above 5 cm, is safe and acceptable technique.

Impact of continuous training through distributed practice for acquisition of minimally invasive surgical skills

BackgroundMinimally invasive surgery (MIS) requires the mastery of manual skills and a specific training is required. Apart from residencies and fellowships in MIS, other learning opportunities utilize massive training, mainly with use of simulators in short courses. A long-term postgraduate course represents an opportunity to learn through training using distributed practice.ObjectiveThe objective of this study is to assess the use of distributed practice for acquisition of basic minimally invasive skills in surgeons who participated in a long-term MIS postgraduate course.MethodsA prospective, longitudinal and quantitative study was conducted among surgeons who attended a 1-year postgraduate course of MIS in Brazil, from 2012 to 2014. They were tested through five different exercises in box trainers (peg-transfer, passing, cutting, intracorporeal knot, and suture) in the first (t0), fourth (t1) and last, eighth, (t2) meetings of this course. The time and penalties of each exercise were collected for each participant. Participant skills were assessed based on time and accuracy on a previously tested score.ResultsFifty-seven surgeons (participants) from three consecutive groups participated in this study. There was a significant improvement in scores in all exercises. The average increase in scores between t0 and t2 was 88% for peg-transfer, 174% for passing, 149% for cutting, 130% for intracorporeal knot, and 120% for suture (p < 0.001 for all exercises).ConclusionLearning through distributed practice is effective and should be integrated into a MIS postgraduate course curriculum for acquisition of core skills.

Percutaneous cholecystoscopy and internal rendezvous for removal of gallstones and common bile duct stones (with video)

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