In search of the best peritoneal adhesion model: comparison of different techniques in a rat model.

BACKGROUND: Adhesion-related complications after abdominal surgery result in significant morbidity and costs. Results from animal studies investigating prevention or treatment of adhesions are limited due to lack of consistency in existing animal models. The aim of this study was to compare quality and quantity of adhesions in four different models and to find the best model. MATERIALS AND METHODS: This study was approved by the University of Missouri Animal Care and Use Committee (ACUC). Forty female rats were randomly assigned to four different groups of 10 animals each. Adhesion created was performed utilizing the four techniques: Group 1 - parietal peritoneum excision (PPE), Group 2 - parietal peritoneum abrasion (PPA), Group 3 - peritoneal button creation (PBC), and Group 4 - cecal abrasion (CA). Rats were allowed to recover and necropsy was performed on postoperative d 14. Adhesions were scored by an established quantitative and qualitative scoring systems. The midline incision served as the control in each animal. RESULTS: The four groups were not equal with respect to both quantity score (P<0.001) and quality score (P=0.042). The PBC group had the highest quantity of adhesions. The highest quality of adhesion was seen in the PPE group. A multivariate analysis carried out to quantify the performance of each model clearly demonstrated that PBC exhibited the best results in terms of both quantity and quality. CONCLUSIONS: The button technique (PBC) is most consistent and reproducible technique for an intra-abdominal adhesion model. This model can help in the study and development of substances to prevent adhesion formation in the future.

Transvaginal repair of a large chronic porcine ventral hernia with synthetic mesh using NOTES.

BACKGROUND: Ventral incisional hernias still remain a common surgical problem. We tested the feasibility of transvaginal placement of a large synthetic mesh to repair a porcine hernia. METHODS: Seven pigs were used in this survival model. Each animal had creation of a 5-cm hernia defect and underwent a transvaginal repair of the defect with synthetic mesh. A single colpotomy was made using a 12-cm trocar for an overtube. The mesh was cut to size and placed through the trocar. A single-channel gastroscope with an endoscopic atraumatic grasper was used for grasping sutures. Further fascial sutures were placed every 5 cm. RESULTS: Mesh repair was feasible in all 7 animals. Mean operative time was 133 minutes. Technical difficulties were encountered. No gross contamination was seen at the time of necropsy. However, 5 animals had positive mesh cultures; 7 had positive cultures in the rectouterine space in enrichment broth or on direct culture. CONCLUSION: Transvaginal placement of synthetic mesh to repair a large porcine hernia using NOTES is challenging but feasible. Future studies need to be conducted to develop better techniques and determine the significance of mesh contamination.

Lessons learned establishing an animal model for endoscopic stent placement to treat gastrojejunal anastomotic leaks after gastric bypass.

BACKGROUND: Anastomotic leaks after Roux-en-Y gastric bypass (RYGB) cause significant morbidity and mortality. Placement of enteral stents may be an improvement to the current treatment, which is withholding of oral intake and total parenteral nutrition. METHODS: We established an open RYGB porcine model with a leak at the gastrojejunostomy in three pigs. A pilot study was then performed in five pigs, where Polyflex stents were placed across the leaking anastomosis and fixed with transmural sutures to the Roux limb. After 2 weeks, endoscopy, fluoroscopy, and necropsy were performed. RESULTS: One pig without stent died on the second postoperative day (POD) due to a volvulus unrelated to the leak. In the other two pigs, leaks with large abscesses were found at necropsy. Stents were placed in five pigs but required open surgical manipulation of the delivery system. One pig died on POD 3 due to a perforation in the posterior gastric wall likely caused by the rigid delivery system. One pig died from gastrojejunostomy leakage on POD 5. The leaks were healed in the remaining three pigs after 2 weeks. In one pig, a perforation of the jejunum 4 cm distal to the anastomosis was found. Stent migration to some extent was seen in all pigs. CONCLUSION: Stent placement and fixation were feasible but had a high complication rate for treatment of a leaking gastrojejunal anastomosis in the open porcine model. The stent may have contributed to healing the leak in some pigs. Further studies should focus on improving stent delivery, sealing of the leak, and prevention of stent migration.

Transgastric cholecystectomy using a prototype endoscope with 2 deflecting working channels (with video).

BACKGROUND: Transgastric cholecystectomy has been shown to be feasible in animal models and human case reports but cumbersome with current available instrumentation. OBJECTIVE: To evaluate a prototype endoscope with 2 working channels with deflectors at the distal tip for performance of transgastric cholecystectomy. DESIGN: Animal study, nonsurvival and survival. ANIMALS: Sixteen male pigs. SETTING: University hospital. INTERVENTION: Transgastric cholecystectomy in 6 nonsurvival pigs by using several different dual-channel endoscopes and 10 survival pigs by using the Olympus dual-channel endoscope with an up-down deflecting channel to the left of the objective lens and a left-right deflecting channel located below the lens. Gallbladder fundic retraction was performed with the aid of one laparoscopic grasper. RESULTS: Cholecystectomy was successful in all survival animals. Median procedure time was 81 minutes (range 31-163 minutes), with a decrease over time. Visualization of all structures was achieved, and clipping of the cystic duct and artery was successful in all cases. Dissection of the gallbladder via the left-right channel was enhanced with retraction via the up-down deflecting channel. Nine of 10 animals survived without complications. One animal died, on postoperative day 2, secondary to peritonitis due to a leak from the gastrotomy site. CONCLUSIONS: This endoscope, with deflecting working channels, allows transgastric cholecystectomy in pigs. The endoscope was stable enough to be used without an overtube and facilitated retraction and dissection. This endoscope is promising for use in transgastric cholecystectomy in human beings.

Laparoscopic Nissen fundoplication is a good option in patients with abnormal esophageal motility.

BACKGROUND: Patients with gastroesophageal reflux disease (GERD) and abnormal esophageal motility are the most controversial subgroup of surgically treated patients because of potentially increased risk of postoperative dysphagia. Our study aim was to determine if Nissen fundoplication is associated with increased postoperative dysphagia in patients with ineffective esophageal motility. METHODS: Medical records of all adult (>18 years old) patients who underwent laparoscopic Nissen fundoplication for GERD over 8 years were reviewed retrospectively. Of the 151 patients, 28 (group A) met manometric criteria for abnormal esophageal motility (<30 mmHg mean contractile pressure or <80% peristalsis), whereas 63 (group B) had normal esophageal function. Sixty patients had no manometric data and were therefore excluded from analysis. Follow-up time ranged from 1 month to 5 years. Outcomes (postoperative dysphagia, recurrence of GERD symptoms, free of medications) were compared between groups. RESULTS: Group A had higher age and American Society of Anesthesiologists (ASA) score (p = 0.016 and 0.020), but this did not correlate with outcome. Two patients (7.1%) in group A and three patients (5.3%) in group B had postoperative dysphagia. When adjusted for follow-up time, there was no significant difference between the groups (p = 0.94). Group B had more cases of recurrent heartburn (10.7% versus 3.6%, p = 0.039), and more patients in this group were back on medications (21.4% versus 7.1%, p < 0.05) CONCLUSIONS: This retrospective study found equally low rates of dysphagia following Nissen fundoplication regardless of baseline esophageal motility. Preoperative esophageal dysmotility therefore does not seem to be a contraindication for laparoscopic Nissen fundoplication.

Transgastric placement of biologic mesh to the anterior abdominal wall.

BACKGROUND: Incisional hernia repairs have a risk of wound complications that may be decreased using a natural orifice transluminal endoscopic surgery (NOTES) approach. The aim of this study was to determine the feasibility and safety of transgastric mesh placement to the anterior abdominal wall in a porcine model as a precursor to future studies of NOTES ventral hernia repair. METHODS: The procedure was done under sterile conditions with a double lumen endoscope using a plastic overtube. The endoscope was placed in the stomach preloaded with an overtube. Entrance of the endoscope and overtube into the peritoneal cavity was performed with the percutaneous endoscopic gastrostomy (PEG) technique. A 13 x 15 cm Surgisis Gold mesh with four corner sutures was delivered through the overtube. Transfascial suture passer and endoscopic grasper were used to externalize the sutures and attach the mesh to the anterior abdominal wall. The gastrotomy was closed with a transabdominal gastropexy. The pigs were sacrificed at 2 weeks. RESULTS: Mesh placement was performed in five pigs. Operative time was 215 min (standard deviation, SD 99 min). The most difficult portion of the procedure involved manipulating the gastric overtube, likely exposing the mesh to bacteria in the stomach. Culture-positive abscesses were present at the mesh in 3/5 animals. The mesh appeared intact in 4/5 animals; one of the infected meshes had delamination of 50% of the mesh. Adhesions to the mesh surface varied from 2% to 100%. At 2 weeks, median mesh size was 116 cm2 (range 96-166 cm2) and median contraction was 41% (range 15-51%). Histologic evaluations demonstrated marked inflammation and fibrosis progressing into the mesh material. CONCLUSIONS: Totally endoscopic transgastric delivery and fixation of a biologic mesh to the anterior abdominal wall is feasible. Challenges remain in designing systems for mesh delivery that exclude gastric content. Once these problems can be surmounted NOTES ventral hernia repair may become an option in man.

Colonic sterilization for natural orifice translumenal endoscopic surgery (NOTES) procedures: a comparison of two decontamination protocols.

BACKGROUND: This study aimed to evaluate the effect of two different sterilization protocols on the bacterial counts in the swine colon as preparation for natural orifice translumenal endoscopic surgery (NOTES) surgery. METHODS: In this study, 16 swine were randomized to two different colonic sterilization protocols: low colonic irrigation using 300 ml of a 1:1 dilution of 10% povidone-iodine (Betadine) with sterile saline, followed by 1 g of cefoxitin dissolved in 300 ml of saline or two consecutive 300-ml irrigations using a quaternary ammonium antimicrobial agent (Onamer M). Colonic cultures were taken before colonic cleansing after a decontamination protocol and after completion of the NOTES procedure. The Invitrogen live/dead bacterial viability kit was used to assess for change in the bacterial load. A qualitative culture of peritoneal fluid was obtained at the end of the NOTES procedure. Colon mucosal biopsies obtained immediately after the sterilization procedure and at the 2-week necropsy point were evaluated for mucosal changes. RESULTS: Protocol 1 resulted in an average 93% decrease in live colonic bacteria versus 90% with protocol 2 (nonsignificant difference). After a NOTES procedure, group 1 had a 62% increase in live bacteria and group 2 had a 31% increase (nonsignificant difference). Peritoneal cultures also were obtained. Bacteria were isolated from the peritoneal fluid of all the animals, and two or more species were isolated from 75% of the animals. There was no evidence of peritoneal infection at necropsy. Reactive epithelial changes and mild inflammation were the only pathologic abnormalities. No changes were noted at histologic evaluation of colonic mucosa after 2 weeks, demonstrating that these were temporary changes. CONCLUSION: Colonic irrigation with Betadine and antibiotics are as effective for bacterial decontamination of the swine colon as a quaternary ammonium compound. The results of this study support the use of either protocol. Despite thorough decontamination, peritoneal contamination occurs. The significance of this for humans is unknown.

Endoscopic colotomy closure for natural orifice transluminal endoscopic surgery using a T-fastener prototype in comparison to conventional laparoscopic suture closure.

BACKGROUND: Safe and efficient endoscopic closure of a colotomy is essential for transcolonic peritoneal access or endoscopic full-thickness resection of the colon, if open or laparoscopic surgery is to be avoided. OBJECTIVE: To compare the feasibility and safety of colotomy closure with the newly developed Tissue Approximation System (TAS, Ethicon Endo-Surgery, Inc.) to conventional laparoscopic suture closure. DESIGN: Prospective randomized survival animal study involving 16 pigs. SETTING: University hospital. INTERVENTIONS: Pigs were randomized for closure of a 2- to 3-cm full-thickness colotomy with the TAS or with a conventional laparoscopic running suture. MAIN OUTCOME MEASUREMENTS: Success of colotomy closure, time of colotomy closure, postoperative infection, and complication rates. RESULTS: Colotomies were successfully closed in all animals. Median closure time (range) was 39.5 minutes (25-95 min) in the TAS group and 23 minutes (16-40 min) in the laparoscopic group (P = .0134). There were no postoperative infections or complications. LIMITATIONS: Closure with the TAS was performed under laparoscopic vision. There was no control group without closure of the colotomy site. CONCLUSIONS: Colotomies are safely closed with the TAS with comparable results to laparoscopic closure. The TAS may serve as a useful tool to close full-thickness colon defects or colotomy sites made for transluminal endoscopic procedures.

Gastrotomy creation and closure for NOTES using a gastropexy technique (with video).

BACKGROUND: Safe and efficient gastrotomy creation and closure is pivotal for natural orifice transluminal endoscopic surgery (NOTES). OBJECTIVE: To test a method of transgastric access and closure with commercially available devices. DESIGN: An animal survival study. SETTING: University hospital. PATIENTS: Fifteen pigs. INTERVENTIONS: By using a surgical suture passer, under endoscopic guidance, 3 percutaneous stay sutures were placed, in a triangular fashion, through the gastric wall. A gastrotomy was created with a dilation balloon, which was introduced over a guidewire through the gastric wall in the center of the 3 sutures. After performing a NOTES procedure, the gastrotomy was closed by tying the sutures. Necropsies were performed after 2 to 4 weeks. MAIN OUTCOME MEASUREMENTS: Success and time of gastrotomy creation and closure, and intraoperative and postoperative complications. RESULTS: Gastrotomies were successfully created and closed in all the animals. The median time to create a gastrotomy was 19 minutes (range 11-85 minutes), and the median closure time was 1 minute (range 1-45 minutes). One pig died on postoperative day 1 because of peritonitis caused by a leaking gastrotomy site that extended beyond the stay sutures. There were no other gastrotomy-related complications. All gastrotomies were well healed at the necropsy. LIMITATION: No control group. CONCLUSIONS: We evaluated a simple method by using the principles of the PEG technique combined with a gastropexy, which is familiar to the majority of endoscopists. Strict attention to the gastrotomy site is needed, because one leak was from the gastrotomy site that extended beyond the stay sutures.

Pattern of hormone receptor status of secondary contralateral breast cancers in patients receiving adjuvant tamoxifen.

In breast cancer patients receiving adjuvant tamoxifen after unilateral treatment, contralateral breast cancer (CBC) is extremely rare. As a result, only limited data are available on the hormone receptor status of CBCs evolving in tamoxifen-treated patients. The aim of our investigation was to evaluate the pattern of hormone receptor status of CBCs in patients treated with adjuvant tamoxifen at our institution. Material was collected from 35 patients. We have found that 27 of the 35 patients included into our investigation developed an estrogen receptor (ER)-positive CBC despite adjuvant tamoxifen. Seven ER-positive CBCs occurred after tamoxifen had been discontinued, and 20 patients developed an ER-positive CBC while receiving tamoxifen. Notably, 80% of these CBCs displayed moderate-to-strong levels of ER. In our opinion, the selection of ER-negative CBCs, which has previously been implicated to be the pivotal mechanism of tumor escape of CBCs evolving in tamoxifen-treated patients, is only one mechanism of tumor escape in patients receiving antiestrogen treatment. The emergence of ER-positive CBCs in the majority of tamoxifen-treated patients suggests that alternative escape mechanisms may be equally relevant. These include the emergence of ER-positive CBCs that display tamoxifen-dependent growth properties, the selection of CBCs that are tamoxifen resistant because of ER mutations with altered ER function, and, finally, the selection of ER-positive CBCs that overexpress c-erbB2.

Collagen- versus gelatine-coated Dacron versus stretch PTFE bifurcation grafts for aortoiliac occlusive disease: long-term results of a prospective, randomized multicenter trial.

BACKGROUND: In this prospective randomized multicenter trial, knitted gelatine-coated Dacron, knitted collagen-coated Dacron, and stretch polytetrafluoroethylene (PTFE) aortic bifurcation grafts were compared for their long-term results. METHODS: Between 1991 and 1998, 149 patients undergoing elective revascularization for aortoiliac occlusive disease were prospectively randomized at 3 tertiary referral centers of vascular surgery. The patients received either gelatine-coated Dacron (GEL-D) grafts (n = 52), collagen-coated Dacron (COL-D) grafts (n = 49), or stretch PTFE grafts (n = 48). RESULTS: No intraoperative deaths were recorded. The 30-day mortality was 4%. The mean follow-up time was 97 months. Primary patency rates were 77% for GEL-D, 78% for COL-D, and 79% for PTFE at 8 years. The differences were not different (P >.8). Secondary corrected 8-year patency rates were also not significantly different (P >.5): 91% for GEL-D, 96% for COL-Dm and 90% for PTFE. Five Dacron and 1 PTFE grafts were affected by infections. CONCLUSIONS: Bifurcation grafts for revascularization of aortoiliac occlusive disease using these 3 materials were comparable in terms of primary and secondary patency and long-term complication rates.

Pilot data on the endoscopic placement of covered metal stents to treat gastrojejunal leaks in a porcine model.

BACKGROUND: Placement of stents may be an alternative option to treat gastrojejunal (GJ) anastomotic leaks after Roux-en-Y gastric bypass (RYGB) surgery. The aim was to evaluate the performance of a covered metal stent (Alimaxx-E, 18 x 100 mm) across a GJ leak in a porcine model. METHODS: In eight pigs, a RYGB was performed and a 1-cm leak was created. A retrogastric and anterogastric GJ was performed equally with four pigs in each group. Stents were placed across the GJ anastomosis using endoscopy and fluoroscopy. The endpoints were position of the stents, healing of the leak, and complications at necropsy. RESULTS: Stent placement was feasible in all pigs it was attempted. In the retrogastric GJ group, pigs without stents survived 2 weeks without complications. Two pigs with stents died on postoperative days (PODs) 4 and 5. In the anterogastric GJ group, one pig with one stent survived 2 weeks with healing of the leak but with stent migration into the Roux limb. The remaining three pigs died between PODs 4 and 6. Pressure necrosis of the Roux limb caused by the distal end of the stent was found in all. CONCLUSIONS: Placement of fully covered metal stents is feasible. The use of small pigs with a thin small bowel wall in combination with relatively large stents was most likely the reason for complications found in all stented animals. Further studies of GJ leaks using these stents will require larger pigs or a different species.

Laparoscopic appendectomy--is it worth the cost? Trend analysis in the US from 2000 to 2005.

BACKGROUND: Although laparoscopic appendectomy is widely used for treatment of appendicitis, it is still unclear if it is superior to the open approach. STUDY DESIGN: From the Nationwide Inpatient Sample 2000 to 2005, hospitalizations with the primary ICD-9 procedure code of laparoscopic (LA) and open appendectomy (OA) were included in this study. Outcomes of length of stay, costs, and complications were assessed by stratified analysis for uncomplicated and complicated appendicitis (perforation or abscess). Regression methods were used to adjust for covariates and to detect trends. Costs were rescaled using the hospital and related services portion of the Medical Consumer Price Index. RESULTS: Between 2000 and 2005, 132,663 (56.3%) patients underwent OA and 102,810 (43.7%) had LA. Frequency of LA increased from 32.2% to 58.0% (p < 0.001); conversion rates decreased from 9.9% to 6.9% (p < 0.001). Covariate adjusted length of stay for LA was approximately 15% shorter than for OA in both uncomplicated and complicated cases (p < 0.001). Adjusted costs for LA were 22% higher in uncomplicated appendicitis and 9% higher in patients with complicated appendicitis (p < 0.001). Costs and length of stay decreased over time in OA and LA. The risk for a complication was higher in the LA group (p < 0.05, odds ratio=1.07, 95% CI 1.00 to 1.14) with uncomplicated appendicitis. CONCLUSIONS: LA results in higher costs and increased morbidity for patients with uncomplicated appendicitis. Nevertheless, LA is increasingly used. Patients undergoing LA benefit from a slightly shorter hospital stay. In general, open appendectomy may be the preferred approach for patients with acute appendicitis, with indication for LA in selected subgroups of patients.

Adjuvant bisphosphonates in endocrine-responsive breast cancer: what is their place in therapy?

Recent advances in the treatment of early breast cancer have improved clinical outcomes and prolonged survival, especially in women with endocrine-responsive disease. However, cancer therapies including cytotoxic chemotherapy, ovarian suppression, and aromatase inhibitors can drastically reduce circulating estrogen, increasing bone loss and fracture risk. Because most women with early breast cancer will live for many years, it is important to protect bone health during cancer therapy. Several recent clinical trials combining adjuvant endocrine therapy with bisphosphonates have demonstrated efficacy for preventing cancer treatment-induced bone loss in pre- and postmenopausal women with early breast cancer. The largest body of evidence supporting the use of adjuvant bisphosphonates comes from studies with zoledronic acid; however, studies with risedronate, ibandronate, and denosumab (a biologic agent) have also demonstrated efficacy for preventing bone loss. Adding zoledronic acid to endocrine therapy prevents bone loss and improves bone mineral density (BMD). In addition, preclinical studies suggest that bisphosphonates have direct and indirect antitumor activity, such as inducing tumor cell apoptosis, reducing tumor cell adhesion and invasion, reducing angiogenesis, activating immune responses, and synergy with chemotherapy agents, among others. Clinical trials have demonstrated significantly improved disease-free survival in patients receiving adjuvant endocrine therapy plus zoledronic acid compared with endocrine therapy alone. Ongoing studies will further define the role of adjuvant bisphosphonates in maintaining bone health and improving clinical outcomes. The available evidence suggests that pre- and postmenopausal patients may receive clinical benefit from including bisphosphonates as part of their adjuvant treatment regimen for endocrine-responsive early breast cancer.

Is Endocrine Therapy Really Pleasant? Considerations about the Long-Term Use of Antihormonal Therapy and Its Benefit/Side Effect Ratio.

Endocrine therapy has become a key part in the adjuvant treatment of hormone responsive breast cancer. The positive effect on relapse risk reduction is well defined, but therapy is not free from bothersome side effects for which estrogen deprivation accounts to a great extent. Since endocrine therapy is usually prescribed for 5 years or longer to optimally display its protective effect, and because physical strain is missing, good tolerability and safety properties are important, particularly in low-risk patients. While tamoxifen has been the standard adjuvant endocrine treatment with well documented efficiency, it is increasingly replaced by third generation aromatase inhibitors due to their better effectiveness and tolerability. Because tamoxifen holds a risk for life-threatening adverse events such as endometrial cancer, pulmonary embolism, and stroke, its recommended duration of therapy is limited to 5 years, also because extension beyond that time did not produce a measurable advantage. While some side effects are present both with tamoxifen and aromatase inhibitors, differences in side effect profiles are well established. Although side effects of aromatase inhibitor-related therapy usually are mild and common to symptoms of menopause, misconception of the symptoms and their mechanism of action, as well as lack of knowledge about how to handle them, can easily lead to dangerous discontinuation of therapy.

Ascariasis in the hepatobiliary system: laparoscopic management.

BACKGROUND: Ascariasis is an endemic disease in developing countries. The parasite can invade the hepatobiliary tree and cause symptoms. Medical therapy can be ineffective in these patients and intervention techniques required. STUDY DESIGN: A retrospective review of patient charts between February 1992 and February 2007 in the Hospital Latinoamericano, Cuenca, Ecuador, was performed to identify patients having surgical or endoscopic treatment for hepatobiliary ascariasis. Patient demographics, treatment algorithms, and outcomes are described and analyzed. RESULTS: There were 13 cases of hepatobiliary infestation by ascaris treated through endoscopy or operation. All patients presented with colicky abdominal pain in the right upper quadrant. Hepatic and biliary ultrasonography identified parasites in 12 patients. In the other patient, a hepatic abscess containing ascaris was found incidentally during cholecystectomy. There were 11 patients with ascariasis in the common bile duct, 1 in whom the cystic duct was occluded, causing acute cholecystitis. In 12 patients, conservative management was attempted and was unsuccessful. Endoscopic extraction was successful in four of these patients. Six patients underwent laparoscopic cholecystectomy, common bile duct exploration with parasite extraction, and T-tube placement. Parasite extraction through common bile duct exploration followed by primary closure was performed in one patient. Cholecystotomy and parasite extraction followed by cholecystectomy were performed in one patient. The final patient had cholecystectomy and parasite extraction from a liver abscess without earlier medical therapy. CONCLUSIONS: Ascariasis in the hepatobiliary system should be considered in the differential diagnosis of upper abdominal pain for patients in populations at risk. When an operation is indicated, it can be accomplished by endoscopic or laparoscopic approach.

Stent placement for benign colonic stenosis: case report, review of the literature, and animal pilot data.

BACKGROUND: Permanent metal stent placement for malignant intestinal obstruction has been proven to be efficient. Temporary stents for benign conditions of the colon and rectum are less studied. This is a case study, review of the literature, and observation from an animal model on placement of stents in the colorectum for benign disease. MATERIALS AND METHODS: A 55-year-old man presented with recurrent obstructions from a benign stricture of the distal sigmoid colon. After failed balloon dilations, a polyester coated stent was placed. The purpose of the stent was to improve symptoms and avoid surgery. The stent was expelled after 5 days. We conducted a literature review of stents placed for benign colorectal strictures and an animal study to evaluate stent migration. RESULTS: In the literature, there were 53 reports of uncovered metal stents, four covered metal stents, and six polyester stents. Patency rates were 71%, and migration rate was 43%. Migration occurred earlier with polyester stents (mean=8 days) versus covered (32 days) or uncovered metal stents (112 days). Severe complications were seen in 23% of patients. Four 45-kg pigs underwent rectosigmoid transection with a 21-mm anastomosis and endoscopic placement of a Polyflex stent. Two stents were secured with suture. Stents without fixation were expelled within 24 h of surgery. Stents with fixation were expelled between postoperative days 2 and 14. CONCLUSION: Stents for the treatment of benign colorectal strictures are safe, with comparable patency rates between stent types. Metal stents can cause severe complications. In a pig model, covered polyester stents tend to migrate early even with fixation. Further investigation needs to focus on new stent designs and/or better fixation.