Frequency of Clinically Significant Findings in the Surgical Pathology Specimen Following Laparoscopic Sleeve Gastrectomy and Concordance with Preoperative Endoscopy: Insights from a Large Single-Center Experience

INTRODUCTION

Endoscopy prior to bariatric surgery is not always performed, and in sleeve gastrectomy (SG), the surgical specimen is not always sent for pathological examination. There is limited data on the frequency of clinically significant findings in SG specimens or correlation with preoperative endoscopy.

METHODS

We reviewed 426 consecutive SG patients to determine the concordance of preoperative endoscopy findings in patients with clinically significant postoperative pathology.

RESULTS

Preoperative endoscopy was performed on 397 patients (93.2%). Three hundred seventy-three patients had preoperative endoscopy and surgical pathology results available. Then, 20/373 (5.4%) patients had potentially significant postoperative pathology, including intestinal metaplasia, autoimmune metaplastic atrophic gastritis (AMAG), gastrointestinal stromal tumors, and/or gastric cancer. The overall incidence of AMAG in the entire cohort was 2.3%. Preoperative gastric biopsies (to include gastric body) identified AMAG in nearly 1/2 of patients. Patients with clinically significant postoperative pathology results had a median [interquartile range] of 3 [3-5] tissue blocks examined as compared to 3 [1-3] for the remainder of the cohort (p < 0.001).

CONCLUSION

This is one of the largest studies describing clinically significant postoperative pathology after SG. AMAG, in particular, is of particular importance as it is associated with a 3-fivefold increase in risk for gastric cancer. The incidence of significant postoperative pathology in this population is small but potentially clinically significant and requires validation in larger studies. We recommend wider sampling in preoperative endoscopy (body and antrum), especially in patients being planned for gastric bypass, consideration for routine pathological examination of SG surgical specimens, with careful gross examination and targeted sampling.

Global benchmarks in primary robotic bariatric surgery redefine quality standards for Roux-en-Y gastric bypass and sleeve gastrectomy

BACKGROUND

Whether the benefits of the robotic platform in bariatric surgery translate into superior surgical outcomes remains unclear. The aim of this retrospective study was to establish the 'best possible' outcomes for robotic bariatric surgery and compare them with the established laparoscopic benchmarks.

METHODS

Benchmark cut-offs were established for consecutive primary robotic bariatric surgery patients of 17 centres across four continents (13 expert centres and 4 learning phase centres) using the 75th percentile of the median outcome values until 90 days after surgery. The benchmark patients had no previous laparotomy, diabetes, sleep apnoea, cardiopathy, renal insufficiency, inflammatory bowel disease, immunosuppression, history of thromboembolic events, BMI greater than 50 kg/m2, or age greater than 65 years.

RESULTS

A total of 9097 patients were included, who were mainly female (75.5%) and who had a mean(s.d.) age of 44.7(11.5) years and a mean(s.d.) baseline BMI of 44.6(7.7) kg/m2. In expert centres, 13.74% of the 3020 patients who underwent primary robotic Roux-en-Y gastric bypass and 5.9% of the 4078 patients who underwent primary robotic sleeve gastrectomy presented with greater than or equal to one complication within 90 postoperative days. No patient died and 1.1% of patients had adverse events related to the robotic platform. When compared with laparoscopic benchmarks, robotic Roux-en-Y gastric bypass had lower benchmark cut-offs for hospital stay, postoperative bleeding, and marginal ulceration, but the duration of the operation was 42 min longer. For most surgical outcomes, robotic sleeve gastrectomy outperformed laparoscopic sleeve gastrectomy with a comparable duration of the operation. In robotic learning phase centres, outcomes were within the established benchmarks only for low-risk robotic Roux-en-Y gastric bypass.

CONCLUSION

The newly established benchmarks suggest that robotic bariatric surgery may enhance surgical safety compared with laparoscopic bariatric surgery; however, the duration of the operation for robotic Roux-en-Y gastric bypass is longer.

Hiatal hernia repair with transoral incisionless fundoplication versus Nissen fundoplication for gastroesophageal reflux disease: A retrospective study

Background and study aims  Concomitant hiatal hernia (HH) repair with transoral incisionless fundoplication (TIF) is a therapeutic option for patients with HH > 2 cm and gastroesophageal reflux disease (GERD). Data comparing this approach with laparoscopic Nissen fundoplication (LNF) are lacking. We performed an exploratory analysis to compare these two approaches' adverse events (AEs) and clinical outcomes. Patients and methods  This was a multicenter retrospective cohort study of HH repair followed by LNF versus HH repair followed by TIF in patients with GERD and moderate HH (2-5 cm). AEs were assessed using the Clavien-Dindo classification. Symptoms (heartburn/regurgitation, bloating, and dysphagia) were compared at 6 and 12 months. Results  A total of 125 patients with HH repair with TIF and 70 with HH repair with LNF were compared. There was no difference in rates of discontinuing or decreasing proton pump inhibitor use, dysphagia, esophagitis, disrupted wrap, and HH recurrence between the two groups ( P  > 0.05). The length of hospital stay (1 day vs. 2 days), 30-day readmission rate (0 vs. 4.3 %), early AE rate (0 vs. 18.6 %), and early serious AE rate (0 vs. 4.3 %) favored TIF (all P  < 0.05). The rate of new or worse than baseline bloating was lower in the TIF group at 6 months (13.8 % vs. 30.0 %, P  = 0.009). Conclusions  Concomitant HH repair with TIF is feasible and associated with lower early and serious AEs compared to LNF. Further comparative efficacy studies are warranted.

Assessment of predictors of early postoperative complications after primary robotically assisted Roux-en-Y gastric bypass: a multicenter, retrospective cohort study

Background

Robotic Roux-en-Y gastric bypass (RRYGB) is performed in an increasing number of bariatric centers worldwide. Previous studies have identified a number of demographic and clinical variables as predictors of postoperative complications after laparoscopic Roux-en-Y gastric bypass (LRYGB). Some authors have suggested better early postoperative outcomes after RRYGB compared to LRYGB. The objective of the present study was to assess potential predictors of early postoperative complications after RRYGB.

Methods

A retrospective analysis of two prospective databases containing patients who underwent RRYGB between 2006 and 2019 at two high volumes, accredited bariatric centers was performed. Primary outcome was rate of 30 day postoperative complications. Relevant demographic, clinical and biological variables were entered in a multivariate, logistic regression analysis to identify potential predictors.

Results

Data of 1276 patients were analyzed, including 958 female and 318 male patients. Rates of overall and severe 30 day complications were 12.5% (160/1276) and 3.9% (50/1276), respectively. Rate of 30 day reoperations was 1.6% (21/1276). The overall gastrointestinal leak rate was 0.2% (3/1276). Among various demographic, clinical and biological variables, male sex and ASA score >2 were significantly correlated with an increased risk of 30 day complication rates on multivariate analysis (OR 1.68 and 1.67, p=0.005 and 0.005, respectively).

Conclusion

This study identified male sex and ASA score >2 as independent predictors of early postoperative complications after RRYGB. These data suggest a potentially different risk profile in terms of early postoperative complications after RRYGB compared to LYRGB. The robotic approach might have a benefit for patients traditionally considered to be at higher risk of complications after LRYGB, such as those with BMI >50. The present study was however not designed to assess this hypothesis and larger, prospective studies are necessary to confirm these results.

The rising tide of revisional surgery: tracking changes in index cases among bariatric-accredited fellowships

Background

The field of bariatric surgery has seen peaks and troughs in the types of metabolic procedures performed. Our primary aim was to evaluate bariatric case volumes among fellows enrolled in bariatric Fellowship Council (FC)-accredited programs. Our secondary aim was to assess trends in revisional case volumes.

Methods

We reviewed de-identified FC case logs for all bariatric surgery-accredited programs from 2010 through 2019. The number of primary sleeve gastrectomy, gastric band, gastric bypass, biliopancreatic diversion, and major revisional bariatric surgical procedures (defined as a revision with creation of a new anastomosis) were graphed for each academic year. Fellows were stratified into quartiles based on the number of revisional operations per year and graphed over ten years. Volumes of primary gastric bypass, major revisions, and total anastomotic cases were compared over time using ANOVA with p < 0.05 considered significant.

Results

Case volumes for 822 fellows were evaluated. Sleeve gastrectomy had a significant surge in 2010 and plateaued in 2016. The fellows’ number of primary gastric bypasses had a non-significant decrease from 84 to 75 cases/fellow from 2010 to 2019. This decrease was offset by a significant increase in major revisional surgery from 8 to 19 cases/fellow. As a result, the number of anastomotic cases did not change significantly over the study time period. Interestingly, as revisional volume has grown, the gap between quartiles of fellowship programs has widened with the 95th percentile growing at a much faster rate than lower quartiles.

Conclusion

The volume of bariatric procedures performed in the last decade among FC fellows follows similar trends to national data. Major revisional cases have doubled with the most robust growth isolated to a small number of programs. As revisional surgery continues to increase, applicants interested in a comprehensive bariatric practice should seek out training programs that offer strong revisional experience.

Endoscopic sleeve gastroplasty for treatment of class 1 and 2 obesity (MERIT): a prospective, multicentre, randomised trial

BACKGROUND

Endoscopic sleeve gastroplasty (ESG) is an endolumenal, organ-sparing therapy for obesity, with wide global adoption. We aimed to explore the efficacy and safety of ESG with lifestyle modifications compared with lifestyle modifications alone.

METHODS

We conducted a randomised clinical trial at nine US centres, enrolling individuals aged 21-65 years with class 1 or class 2 obesity and who agreed to comply with lifelong dietary restrictions. Participants were randomly assigned (1:1·5; with stratified permuted blocks) to ESG with lifestyle modifications (ESG group) or lifestyle modifications alone (control group), with potential retightening or crossover to ESG, respectively, at 52 weeks. Lifestyle modifications included a low-calorie diet and physical activity. Participants in the primary ESG group were followed up for 104 weeks. The primary endpoint at 52 weeks was the percentage of excess weight loss (EWL), with excess weight being that over the ideal weight for a BMI of 25 kg/m². Secondary endpoints included change in metabolic comorbidities between the groups. We used multiple imputed intention-to-treat analyses with mixed-effects models. Our analyses were done on a per-protocol basis and a modified intention-to-treat basis. The safety population was defined as all participants who underwent ESG (both primary and crossover ESG) up to 52 weeks.

FINDINGS

Between Dec 20, 2017, and June 14, 2019, 209 participants were randomly assigned to ESG (n=85) or to control (n=124). At 52 weeks, the primary endpoint of mean percentage of EWL was 49·2% (SD 32·0) for the ESG group and 3·2% (18·6) for the control group (p<0·0001). Mean percentage of total bodyweight loss was 13·6% (8·0) for the ESG group and 0·8% (5·0) for the control group (p<0·0001), and 59 (77%) of 77 participants in the ESG group reached 25% or more of EWL at 52 weeks compared with 13 (12%) of 110 in the control group (p<0·0001). At 52 weeks, 41 (80%) of 51 participants in the ESG group had an improvement in one or more metabolic comorbidities, whereas six (12%) worsened, compared with the control group in which 28 (45%) of 62 participants had similar improvement, whereas 31 (50%) worsened. At 104 weeks, 41 (68%) of 60 participants in the ESG group maintained 25% or more of EWL. ESG-related serious adverse events occurred in three (2%) of 131 participants, without mortality or need for intensive care or surgery.

INTERPRETATION

ESG is a safe intervention that resulted in significant weight loss, maintained at 104 weeks, with important improvements in metabolic comorbidities. ESG should be considered as a synergistic weight loss intervention for patients with class 1 or class 2 obesity. This trial is registered with ClinicalTrials.gov, NCT03406975.

FUNDING

Apollo Endosurgery, Mayo Clinic.

Palliative Endoscopic Salvage of a Functionally Obstructed Gastrojejunostomy - Report of Technique

BACKGROUND

Gastric outlet obstruction secondary to foregut gastrointestinal malignancies can be managed with a variety of medical, endoscopic, and surgical options. Laparoscopic gastrojejunostomy is an option for those patients who are able to tolerate an operation as a long-term palliative option. This operation may be associated with some significant postoperative technical and nontechnical complications, including delayed gastric emptying. This paper describes an incision-less, endoscopic option that we propose can be used to salvage a functionally obstructed gastrojejunostomy.

CASE DESCRIPTION

A 57-year old male patient had a history of pancreatic adenocarcinoma causing gastric outlet obstruction and underwent a previously created surgical gastrojejunostomy at an outside hospital. His procedure was complicated by anastomotic leak and essentially persistent obstructive symptoms secondary to delayed gastric emptying. Though his anastomosis was demonstrably patent, these symptoms were thought to be secondary to a functional obstruction at the gastrojejunostomy. After repeated workups and many failed attempts to treat these symptoms, he ultimately underwent endoscopic placement of an uncovered colonic stent into the efferent limb of his gastrojejunostomy. This allowed for preferential drainage of gastric contents down the efferent limb, and improvement of his delayed gastric emptying.

CONCLUSIONS

In a select group of patients with advanced foregut malignancy, and with high re-operative risks, salvage endoscopic stenting may be useful in the palliation of symptoms from a functionally obstructed gastrojejunostomy.

Thromboelastography-Based Profiling of Coagulation Status in Patients Undergoing Bariatric Surgery: Analysis of 422 Patients

INTRODUCTION/PURPOSE

Some clinical indicators suggest hypercoagulability/hyperaggregability in patients with morbid obesity. Thromboelastography (TEG®) has been used to profile coagulation status in surgical patients. We aimed to assess coagulation profiles in patients with morbid obesity undergoing bariatric surgery by correlating demographic and patient characteristics to pre-operative TEG® values.

MATERIALS AND METHODS

Pre-operative TEG® values from 422 patients undergoing bariatric surgery were evaluated. TEG® results were analyzed by gender, use of medications known to alter the coagulation profile, and body mass index (BMI).

RESULTS

Patients have a mean of 45.03 ± 11.8 years, female (76.3%), and with a mean BMI of 42 kg/m ¹. The overall coagulation profile of female patients was significantly different from males, even in the sub-cohort without use of medications known to alter coagulation. The majority of patients (94%) with a G value > 15 dynes/cm ¹ (clot strength) were female. In females, there was no association between BMI and TEG® values; however, in men, there was a statistically significant difference in TEG® values for those with BMI < 40 kg/m ¹ compared to those with BMI > 50 kg/m².

CONCLUSIONS

TEG®-based analysis of coagulation profiles offers unique insights. Compared to laboratory normal values (R time, angle, maximal amplitude, and G values), patients with morbid obesity may have a tendency for hypercoagulability/hyperaggregability, with mean values at the higher limit. A significant hypercoagulable difference in TEG® values was identified in female as compared to male patients. Male patients with a BMI greater than 50 kg/m² were also found to be increasingly hypercoagulable.

Outcomes of primary versus revisional robotically assisted laparoscopic Roux-en-Y gastric bypass: a multicenter analysis of ten-year experience

Background

Postoperative morbidity after laparoscopic bariatric surgery is considered higher for patients undergoing revisional versus primary procedures. The objective of this retrospective cohort study was to compare outcomes between patients undergoing primary versus revisional robotically assisted laparoscopic (RAL) Roux-en-Y gastric bypass (RYGB).

Methods

Data of all patients who underwent RAL primary and revisional RYGB between 2009 and 2019 at two accredited, high-volume bariatric surgery centers—the Memorial Hermann – Texas Medical Center, Houston, TX, and the Tower Health, Reading Hospital, Reading, PA, were analyzed. Primary outcomes were early (< 30 days) and overall postoperative complications. Secondary outcomes included intraoperative complications, operative times, conversions to laparotomy, length of hospital stay, early (< 30 days) postoperative readmissions and deaths.

Results

Data of 1072 patients were analyzed, including 806 primary and 266 revisional RAL RYGB procedures. Longer operative times (203 versus 154 min, P < 0.001), increased number of readmissions for oral intolerance (10.5% versus 6.7%, P = 0.046) and higher rate of gastrojejunal stricture (6.4% versus 2.7%, P = 0.013) were found in the revisional group. Gastrointestinal leak rates were 0.2% for the primary versus 1.1% for the revisional group (P = 0.101). Early (< 30 days) reoperations rates were 2.2% for the primary versus 1.1% for the revisional group (P = 0.318). There were no statistically significant differences between groups in overall and severe complication rates.

Conclusion

Patients undergoing RAL primary and revisional RYGB had comparable overall outcomes, with a non-significant higher early complication rate in the revisional group. Despite the study being underpowered to detect differences in specific complication rates, the morbidity seen in the revisional RYGB group remains markedly below literature reports of revisional laparoscopic RYGB and might suggest a benefit of robotic assistance. Further prospective studies are needed to confirm these results.

Safety of robotic assisted laparoscopic recurrent paraesophageal hernia repair: insights from a large single institution experience

BACKGROUND

Laparoscopic repair of recurrent as opposed to primary paraesophageal hernias (PEHs) are historically associated with increased peri-operative complication rates, worsened outcomes, and increased conversion rates. The robotic platform may aid surgeons in these complex revision procedures. The aim of this study was to compare the outcomes of patients undergoing robotic assisted laparoscopic (RAL) repair of recurrent as opposed to primary PEHs.

METHODS

Patients undergoing RAL primary and recurrent PEH repairs from 2009 to 2017 at a single institution were reviewed. Demographics, use of mesh, estimated blood loss, intra-operative complications, conversion rates, operative time, rates of esophageal/gastric injury, hospital length of stay, re-admission/re-operation rates, recurrence, dysphagia, gas bloat, and pre- and post-operative proton pump inhibitor (PPI) use were analyzed. Analysis was accomplished using Chi-square test/Fischer's exact test for categorical variables and the Mann-Whitney U test for continuous variables.

RESULTS

There were 298 patients who underwent RAL PEH repairs (247 primary, 51 recurrent). They were followed for a median (interquartile range) of 120 (44, 470) days. There were no significant differences in baseline demographics between groups. Patients in the recurrent PEH group had longer operative times, increased use of mesh, and increased length of hospital stay. They were also less likely to undergo fundoplication. There were no significant differences in estimated blood loss, incidence of intra-operative complications, re-admission rates, incidence of post-operative dysphagia and gas bloat, and incidence of post-operative PPI use. There were no conversions to open operative intervention or gastric/esophageal injury/leaks.

CONCLUSIONS

Although repair of recurrent PEHs are historically associated with worse outcomes, in this series, RAL recurrent PEH repairs have similar peri-operative and post-operative outcomes as compared to primary PEH repairs. Whether this is secondary to the potential advantages afforded by the robotic platform deserves further study.

Correction to: Trocar site closure with a novel anchor-based (neoClose®) system versus standard suture closure: a prospective randomized controlled trial

After careful review, the authors have noticed the following mistakes in the article entitled "Trocar site closure with a novel anchor based (neoClose®) system versus standard suture closure: A prospective randomized controlled trial": - Correct closure times are 19.9 seconds (SD 9.9) for the study group and 31.0 seconds (SD 20.1) for the control group (initial incorrect values were 20.2 seconds (SD 10.1) and 30 seconds (SD 19.1) respectively). The new correct P-value is <0.0001 (initial incorrect P-value was 0.0002). - Correct maximal needle depth values are 3.2 cm (SD 0.93) for the study group and 4.9 cm (SD 1.97) for the control group (initial incorrect values were 3.3 cm (SD 0.9) and 5.2 cm (SD 1.6) respectively). P-value remains unchanged at <0.0001. For these two outcomes, some values of control group patients were mistakenly included in the study group. These errors only marginally affected the mean and standard deviation values. Statistical significance of the results was not affected and the conclusions of the study remain unchanged.

The Influence of the Orbera Intragastric Balloon Filling Volumes on Weight Loss, Tolerability, and Adverse Events: a Systematic Review and Meta-Analysis

BACKGROUND

The Orbera intragastric balloon (IGB) has been approved by the US Food and Drug Administration for use in patients with a body mass index (BMI) between 30 and 40 kg/m² and is in wide use worldwide as a primary and bridge obesity management tool. The balloon filling volume (BFV) ranges between 400 and 700 mL of saline. Our objective was to determine whether there is an association between BFV and clinically relevant endpoints, namely weight loss outcomes, balloon tolerability, and adverse events.

METHODS

A systematic review of studies investigating the use of the Orbera IGB system for obesity treatment was performed. Data was examined using random effects modelling and meta-regression analyses.

RESULTS

Forty-four studies (n = 5549 patients) reported BFV and % total body weight loss (TBWL) at 6 months. Pooled %TBWL at 6 months was 13.2% [95% CI 12.3-14.0]. A funnel plot demonstrated a low risk of publication bias. Meta-regression showed no statistically significant association between filling volume and %TBWL at 6 months (p = 0.268). Higher BFV was associated with lower rates of esophagitis (slope = -0.008, p < 0.001) and prosthesis migration (slope = -0.015, p < 0.001). There was no association between BFV and early removal (p = 0.1), gastroesophageal reflux symptom (p = 0.64), or ulcer rates (p = 0.09).

CONCLUSIONS

No association was observed between Orbera IGB filling volume and weight loss outcomes. Higher volumes appear to be associated with lower migration and esophagitis rates; thus, a balloon filling volume of 600-650 mL is recommended.

Multicenter review of robotic versus laparoscopic ventral hernia repair: is there a role for robotics?

BACKGROUND

The utilization of robotic platforms for general surgery procedures such as hernia repair is growing rapidly in the United States. A limited amount of data are available evaluating operative outcomes in comparison to standard laparoscopic surgery. We completed a retrospective review comparing robotic and laparoscopic ventral hernia repair to provide safety and outcomes data to help design a future prospective trial design.

METHODS

A retrospective review of 215 patients undergoing ventral hernia repair (142 robotic and 73 laparoscopic) was completed at two large academic centers. Primary outcome measure evaluated was recurrence. Secondary outcomes included incidence of primary fascial closure, and surgical site occurrences.

RESULTS

Propensity for treatment match comparison demonstrated that robotic repair was associated with a decreased incidence of recurrence (2.1 versus 4.2%, p < 0.001) and surgical site occurrence (4.2 versus 18.8%, p < 0.001). This may be because robotic repair was associated with increased incidence of primary fascial closure (77.1 versus 66.7%, p < 0.01). Analysis of baseline patient populations showed that robotic repairs were completed on patients with lower body mass index (28.1 ± 3.6 versus 34.2 ± 6.4, p < 0.001) and fewer comorbidities.

CONCLUSIONS

Our retrospective data show that robotic repair was associated with decreased recurrence and surgical site occurrence. However, the differences noted in the patient populations limit the interpretability of these results. As adoption of robotic ventral hernia repair increases, prospective trials need to be designed in order to investigate the efficacy, safety, and cost effectiveness of this evolving technique.

Transoral outlet reduction with full thickness endoscopic suturing for weight regain after gastric bypass: a large multicenter international experience and meta-analysis

BACKGROUND AND AIMS

Many patients who undergo bariatric surgery will experience weight regain and effective strategies are needed to help these patients. A dilated gastrojejunal anastomosis (GJA) has been associated with weight recidivism after Roux-en-Y gastric bypass surgery (RYGB). Endoscopic transoral outlet reduction (TORe) with a full thickness endoscopic suturing device (Overstitch, Apollo Endosurgery, Austin, TX) is a minimally invasive therapeutic option. The primary aim of this project was to examine the safety and long-term efficacy data from three bariatric surgery centers and to conduct a systematic review and meta-analysis of the existing literature.

METHODS

Patients who underwent TORe with the Overstitch device from Jan 2013 to Nov 2016 at 3 participating bariatric surgery centers were included in the multicenter analysis. For the systematic review and meta-analysis, a comprehensive search of multiple English databases was conducted. Random effects model was used.

RESULTS

130 consecutive patients across three centers underwent TORe with an endolumenal suturing device. These patients (mean age 47; mean BMI 36.8) had experienced 24.6% weight regain from nadir weight after RYGB. Average weight lost at 6, 12, and 18 months after TORe was 9.31 ± 6.7 kg (N = 84), 7.75 ± 8.4  kg (N = 70), 8 ± 8.8 kg (N = 46) (p < 0.01 for all three time points), respectively. The meta-analysis included 330 patients. The pooled weight lost at 12 months was 8.4 kg (95% CI 6.5-10.3) with no significant heterogeneity across included studies (p = 0.07). Overall, 14% of patients experienced nausea, 18% had pain and 8% required a repeat EGD. No serious adverse events reported.

CONCLUSION

When implemented as part of a multidisciplinary intervention, TORe using endolumenal suturing is safe, reproducible, and effective approach to manage weight recidivism after RYGB and should be utilized early in the management algorithm of these patients.

Endoscopic removal of eroded adjustable gastric band in a pregnant patient

Complications of the laparoscopic adjustable gastric band, including erosion, have been well described. Increasingly, endoscopic techniques are being utilized to manage complications of this and other weight loss procedures. The authors presented what was believed to be one of the first reported cases of successful endoscopic removal of an eroded gastric band during pregnancy. A complete description of the case and review of the relevant literature is provided. Endoscopy for management of eroded adjustable gastric bands needs to be part of the armamentarium of surgeons and endoscopists who deal with complications of weight loss surgery.

Controlled infection with a therapeutic virus defines the activation kinetics of human natural killer cells in vivo

Human natural killer (NK) cells play an important role in anti-viral immunity. However, studying their activation kinetics during infection is highly problematic. A clinical trial of a therapeutic virus provided an opportunity to study human NK cell activation in vivo in a controlled manner. Ten colorectal cancer patients with liver metastases received between one and five doses of oncolytic reovirus prior to surgical resection of their tumour. NK cell surface expression of the interferon-inducible molecules CD69 and tetherin peaked 24-48 h post-infection, coincident with a peak of interferon-induced gene expression. The interferon response and NK cell activation were transient, declining by 96 h post-infection. Furthermore, neither NK cell activation nor the interferon response were sustained in patients undergoing multiple rounds of virus treatment. These results show that reovirus modulates human NK cell activity in vivo and suggest that this may contribute to any therapeutic effect of this oncolytic virus. Detection of a single, transient peak of activation, despite multiple treatment rounds, has implications for the design of reovirus-based therapy. Furthermore, our results suggest the existence of a post-infection refractory period when the interferon response and NK cell activation are blunted. This refractory period has been observed previously in animal models and may underlie the enhanced susceptibility to secondary infections that is seen following viral infection.