Correlating actual one-year weight loss with predicted weight loss by the MBSAQIP: bariatric surgical risk/benefit calculator.

BACKGROUND: The American Society for Metabolic and Bariatric Surgery has released a Bariatric Surgical Risk/Benefit Calculator, an online tool with which patients and providers can input patient preoperative information and predict their 1-year weight loss. We seek to validate our institutional data with the national database and investigated patient factors that influence lack of treatment effect after bariatric surgery. MATERIALS AND METHODS: A retrospective review of all prospectively collected data of bariatric surgeries performed at Yale New Haven Hospital from 2017 to 2018 was conducted. By entering data into the MBSAQIP Calculator, the 1-year predicted Body Mass Index was calculated and compared to the actual weight loss. Statistical analysis was performed using an unpaired t-test with Welch's correction (Prism 8, GraphPad). RESULTS: The average difference between the actual and predicted weight loss at 1-year for 327 patients was 3.6 BMI points. When the actual weight loss was compared to predicted BMI at 1 year, a high correlation was found (R = 0.6, P = 0.003). We examined the outliers with a comparison of weight loss for those patients who's BMI fell within 5 points of the predicted versus those whose BMI recorded above 5. It was discovered those patients who had higher than 5 BMI points than predicted, had higher preoperative BMI (46.1 vs 43.6, P = 0.008). CONCLUSIONS: The MBSAQIP calculator is a useful tool to guide surgeons with decision-making and informed consent. Our institution's 1-year weight loss data correlated closely with that predicted. From the outliers, we found that patients who did not meet the predicted weight loss had significantly higher preoperative BMI. This may alter preoperative discussions with class 3 or over obese patients regarding expected weight loss and warrant investigations with the national database to develop modifications of the calculator.

The NOVEL trial: natural orifice versus laparoscopic cholecystectomy-a prospective, randomized evaluation.

INTRODUCTION: The evolution of Natural Orifice Translumenal Endoscopic Surgery® (NOTES®) represents a case study in surgical procedural evolution. Beginning in 2004 with preclinical feasibility studies, and followed by the creation of the NOSCAR® collaboration between The Society of American Gastrointestinal and Endoscopic Surgeons and the American Society for Gastrointestinal Endoscopy, procedural development followed a stepwise incremental pathway. The work of this consortium has included white paper analyses, obtaining outside independent funding for basic science and procedural development, and, ultimately, the initiation of a prospective randomized clinical trial comparing NOTES® cholecystectomy as an alternative procedure to laparoscopic cholecystectomy. METHODS: Ninety patients were randomized into a randomized clinical trial with the primary objective of demonstrating non-inferiority of the transvaginal and transgastric arms to the laparoscopic arm. In the original trial design, there were both transgastric and transvaginal groups to be compared to the laparoscopic control group. However, after enrollment and randomization of 6 laparoscopic controls and 4 transgastric cases into the transgastric group, this arm was ultimately deemed not practical due to lagging enrollment, and the arm was closed. Three transgastric via the transgastric approach were performed in total with 9 laparoscopic control cases enrolled through the TG arm. Overall a total of 41 transvaginal and their 39 laparoscopic cholecystectomy controls were randomized into the study with 37 transvaginal and 33 laparoscopic cholecystectomies being ultimately performed. Overall total operating time was statistically longer in the NOTES® group: 96.9 (64.97) minutes versus 52.1 (19.91) minutes. RESULTS: There were no major adverse events such as common bile duct injury or return to the operating room for hemorrhage. Intraoperative blood loss, length of stay, and total medication given in the PACU were not statistically different. There were no conversions in the NOTES® group to a laparoscopic or open procedure, nor were there any injuries, bile leaks, hemorrhagic complications, wound infections, or wound dehiscence in either group. There were no readmissions. Visual Analogue Scale (VAS) pain scores were 3.4 (CI 2.82) in the laparoscopic group and 2.9 (CI 1.96) in the transvaginal group (p = 0.41). The clinical assessment on cosmesis scores was not statistically different when recorded by clinical observers for most characteristics measured when the transvaginal group was compared to the laparoscopic group. Taken as a whole, the results slightly favor the transvaginal group. SF-12 scores were not statistically different at all postoperative time points except for the SF-12 mental component which was superior in the transvaginal group at all time points (p < 0.05). CONCLUSION: The safety profile for transvaginal cholecystectomy demonstrates that this approach is safe and produces at least non-inferior clinical results with superior cosmesis, with a transient reduction in discomfort. The transvaginal approach to cholecystectomy should no longer be considered experimental. As a model for intersociety collaboration, the study demonstrated the ultimate feasibility and success of partnership as a model for basic research, procedural development, fundraising, and clinical trial execution for novel interventional concepts, regardless of physician board certification.

Gallbladder Agenesis: A Case Report.

Gallbladder agenesis (GA) is an extremely rare congenital entity. The incidence is around 1 per 6500 live births. The majority of patients, estimated between 50 to 70 percent, remain asymptomatic while those who are symptomatic report symptoms mimicking biliary colic. Initial workup for suspected gallbladder pathology such as right upper quadrant ultrasound (US) can be misleading or inconclusive. Furthermore, advanced diagnostic studies such as hepatobiliary iminodiacetic acid (HIDA) scan and endoscopic retrograde cholangio-pancreatography (ERCP) may report non-visualization of the gallbladder and erroneously lead providers to a diagnosis of cystic duct obstruction rather than GA. Consequently, some GA patients are only finally diagnosed intraoperatively. Surgery can be risky in these patients because unnecessary dissection while looking for the non-existent gallbladder can result in injury of the biliary tree, hepatic vasculature, or small bowel. Therefore, clinicians should keep GA on their differential diagnosis list and imaging modalities such as magnetic resonance cholangiopancreatography (MRCP) should be obtained when other tests prove inconclusive. We report a 35-year-old female presenting with chronic symptoms consistent with biliary colic and an equivocal US reported as cholelithiasis. She underwent laparoscopy during which the absence of the gallbladder was noted. Postoperative MRCP confirmed the diagnosis of GA.

Graphic and haptic simulation for transvaginal cholecystectomy training in NOTES.

BACKGROUND: Natural Orifice Transluminal Endoscopic Surgery (NOTES) provides an emerging surgical technique which usually needs a long learning curve for surgeons. Virtual reality (VR) medical simulators with vision and haptic feedback can usually offer an efficient and cost-effective alternative without risk to the traditional training approaches. Under this motivation, we developed the first virtual reality simulator for transvaginal cholecystectomy in NOTES (VTEST™). METHODS: This VR-based surgical simulator aims to simulate the hybrid NOTES of cholecystectomy. We use a 6DOF haptic device and a tracking sensor to construct the core hardware component of simulator. For software, an innovative approach based on the inner-spheres is presented to deform the organs in real time. To handle the frequent collision between soft tissue and surgical instruments, an adaptive collision detection method based on GPU is designed and implemented. To give a realistic visual performance of gallbladder fat tissue removal by cautery hook, a multi-layer hexahedral model is presented to simulate the electric dissection of fat tissue. RESULTS: From the experimental results, trainees can operate in real time with high degree of stability and fidelity. A preliminary study was also performed to evaluate the realism and the usefulness of this hybrid NOTES simulator. CONCLUSIONS: This prototyped simulation system has been verified by surgeons through a pilot study. Some items of its visual performance and the utility were rated fairly high by the participants during testing. It exhibits the potential to improve the surgical skills of trainee and effectively shorten their learning curve.

Face and content validation of a Virtual Translumenal Endoscopic Surgery Trainer (VTEST™).

BACKGROUND: Natural orifice translumenal endoscopic surgery (NOTES) is an emerging surgical paradigm, where peritoneal access is achieved through one of the natural orifices of the body. It is being reported as a safe and feasible surgical technique with significantly reduced external scarring. Virtual Translumenal Endoscopic Surgical Trainer (VTEST™) is the first virtual reality simulator for the NOTES. The VTEST™ simulator was developed to train surgeons in the hybrid transvaginal NOTES cholecystectomy procedure. The initial version of the VTEST™ simulator underwent face validation at the 2013 Natural Orifice Surgery Consortium for Assessment and Research (NOSCAR) summit. Several areas of improvement were identified as a result, and the corresponding modifications were implemented in the simulator. This manuscript outlines the results of the subsequent evaluation study, performed in order to assess the face and content validity of the latest VTEST™ simulator. METHODS: Twelve subjects participated in an institutional review board-approved study that took place at the 2014 NOSCAR summit. Six of the 12 subjects, who are experts with NOTES experience, were used for face and content validation. The subjects performed the hybrid transvaginal NOTES cholecystectomy procedure on VTEST™ that included identifying the Calot's triangle, clipping and cutting the cystic duct/artery, and detaching the gallbladder. The subjects then answered five-point Likert scale feedback questionnaires for face and content validity. RESULTS: Overall, subjects rated 12/15 questions as 3.0 or greater (60 %), for face validity questions regarding the realism of the anatomical features, interface, and the tasks. Subjects also highly rated the usefulness of the simulator in learning the fundamental NOTES technical skills (3.50 ± 0.84). Content validity results indicate a high level of usefulness of the VTEST™ for training prior to operating room experience (4.17 ± 0.75).

Transvaginal cholecystectomy learning curve.

BACKGROUND: There are few surgeons in the United States, within private practice and academic centers, currently performing transvaginal cholecystectomies (TVC). The lack of exposure to TVC during residency or fellowship training, coupled with a poorly defined learning curve, further limits interested surgeons who want to apply this technique to their practice. This study describes the learning curve encountered during the introduction of TVC to our academic facility. METHODS: This study is an analysis of consecutive TVCs performed between August 14, 2009 and August 3, 2012 at an academic center. The TVC patients were divided into sequential quartiles (n = 15/16). The learning curve outcome was measured as the operative time of TVC patients and compared to the operative time of female laparoscopic cholecystectomy (LC) patients performed during the same time period. RESULTS: Sixty-one patients underwent a TVC with a mean age of 38 ± 12 years and mean BMI was 29 ± 6 kg/m(2). Sixty-seven female patients who underwent a LC with average age 41 ± 15 years and average BMI 33 ± 12 kg/m(2). The average operative time of LC patients and TVC patients was 48 ± 20 and 60 ± 17 min, respectively. Significant improvement in TVC operative times was seen between the first (n = 15 TVCs) and second quartiles (p = 0.04) and stayed relatively constant for third quartile, during which there was no statistically significant difference between the mean LC operative time for the second and third TVC quartiles CONCLUSIONS: The learning curve of a fellowship-trained surgeon introducing TVC to their surgical repertoire, as measured by improved operative times, can be achieved with approximately 15 cases.

PERIOPERATIVE PAIN CONTROL IN GASTROINTESTINAL SURGERY.

Perioperative pain control in the setting of gastrointestinal surgery presents unique challenges for the clinician, including the incidence of ileus and its potential exacerbation by analgesics, large incisions, patient characteristics and a wide variety of other factors. At the same time, optimizing postoperative pain control is of key significance in this patient population and has implications for both medical and surgical outcomes, length of hospital stay and associated costs and risks of developing chronic postsurgical pain. Data from recent clinical trials and other studies have highlighted the impact of specific surgical and anesthetic techniques on post-operative pain for several types of abdominal surgeries, including pancreatoduodenectomy, hepatectomy, gastric bypass, cholecystectomy, colectomy, and appendectomy. The management of pain may be optimized through the multidisciplinary and concerted efforts between clinicians involved in the perioperative care of patients undergoing gastrointestinal surgery.

Complications of transvaginal natural orifice transluminal endoscopic surgery: a series of 102 patients.

OBJECTIVE: To review the complications encountered in our facility and in previously published studies of transvaginal (TV) natural orifice transluminal endoscopic surgery (NOTES) to date. BACKGROUND: TV NOTES is currently observed with critical eyes from the surgical community, despite encouraging data to suggest improved short-term recovery and pain. METHODS: All TV NOTES procedures performed in female patients between 18 and 65 years of age were included. The median follow-up was 90 days. The TV appendectomies and ventral hernia repairs were pure NOTES, through a SILS port in the vagina, whereas TV cholecystectomies were hybrid procedures with the addition of a 5-mm port in the umbilicus. RESULTS: A total of 102 TV NOTES procedures, including 72 TV cholecystectomies, 24 TV appendectomies, and 6 TV ventral hernia repairs, were performed. The average age was 37 years old and body mass index was 29 kg/m. Three major and 7 minor complications occurred. The first major complication was a rectal injury during a TV access port insertion. The second major complication was an omental vessel bleed after a TV cholecystectomy. The third complication was an intra-abdominal abscess after a TV appendectomy. Seven minor complications were urinary retention (4), transient brachial plexus injury, dislodgement of an intrauterine device, and vaginal granulation tissue. CONCLUSIONS: As techniques in TV surgery are adopted, inevitably, complications may occur due to the inherent learning curve. Laparoscopic instruments, although adaptable to TV approaches, have yet to be optimized. A high index of suspicion is necessary to identify complications and optimize outcomes for patients.

Comparison of immediate postoperative pain after transvaginal versus traditional laparoscopic cholecystectomy.

BACKGROUND: Transvaginal cholecystectomy (TVC) is the most common natural orifice transluminal surgery (NOTES) performed in women, yet there is a paucity of data on intraoperative and immediate postoperative pain management. Previous studies have demonstrated that NOTES procedures are associated with less postoperative pain and faster recovery times. This study analyzes intraoperative and postoperative opioid use for TVC compared with traditional four-port laparoscopic cholecystectomies (LCs). METHODS: This is a retrospective analysis of consecutive TVC and LC female patients between August 2009 and August 2012 in an academic institution. We compared demographics, intraoperative and postoperative opioid use and times in the operating room (OR) and in the post anesthesia care unit (PACU). RESULTS: A total of 68 TVC and 67 LC patients were included in this study. The TVC and LC groups were similar in terms of age (both 41 years) and body mass index (29 and 31 kg/m2, respectively). The intraoperative preparation, surgical, and emergence times were significantly longer for the TVC than for the LC (p ≤ 0.01). Compared with the LC group, the intraoperative opioid requirement was significantly greater (TVC 27 mg vs. LC 25 mg; p = 0.003), but after adjusting for anesthesia time, the difference in OR opioid consumption became non-significant (p = 0.08). The PACU opioid requirement (TVC 2.5 vs. LC 5 mg; p = 0.04) was significantly lower for the TVC group, and a greater proportion of patients did not need any pain medications (TVC 38 % vs. LC 21 %; p = 0.04), compared with the LC group. The average PACU pain scores were not significantly different between the groups (p = 0.45). CONCLUSION: TVC patients did not experience more pain than LC patients. Although the average pain scores of TVC patients did not differ from those of the LC patients, TVC patients did require less pain medication in the PACU.

A comparison of NOTES transvaginal and laparoscopic cholecystectomy procedures based upon task analysis.

BACKGROUND: A virtual reality-based simulator for natural orifice translumenal endoscopic surgery (NOTES) procedures may be used for training and discovery of new tools and procedures. Our previous study (Sankaranarayanan et al. in Surg Endosc 27:1607-1616, 2013) shows that developing such a simulator for the transvaginal cholecystectomy procedure using a rigid endoscope will have the most impact on the field. However, prior to developing such a simulator, a thorough task analysis is necessary to determine the most important phases, tasks, and subtasks of this procedure. METHODS: 19 rigid endoscope transvaginal hybrid NOTES cholecystectomy procedures and 11 traditional laparoscopic procedures have been recorded and de-identified prior to analysis. Hierarchical task analysis was conducted for the rigid endoscope transvaginal NOTES cholecystectomy. A time series analysis was conducted to evaluate the performance of the transvaginal NOTES and laparoscopic cholecystectomy procedures. Finally, a comparison of electrosurgery-based errors was performed by two independent qualified personnel. RESULTS: The most time-consuming tasks for both laparoscopic and NOTES cholecystectomy are removing areolar and connective tissue surrounding the gallbladder, exposing Calot's triangle, and dissecting the gallbladder off the liver bed with electrosurgery. There is a positive correlation of performance time between the removal of areolar and connective tissue and electrosurgery dissection tasks in NOTES (r = 0.415) and laparoscopic cholecystectomy (r = 0.684) with p < 0.10. During the electrosurgery task, the NOTES procedures had fewer errors related to lack of progress in gallbladder removal. Contrarily, laparoscopic procedures had fewer errors due to the instrument being out of the camera view. CONCLUSION: A thorough task analysis and video-based quantification of NOTES cholecystectomy has identified the most time-consuming tasks. A comparison of the surgical errors during electrosurgery gallbladder dissection establishes that the NOTES procedure, while still new, is not inferior to the established laparoscopic procedure.

Toward scar-free surgery: an analysis of the increasing complexity from laparoscopic surgery to NOTES.

BACKGROUND: NOTES is an emerging technique for performing surgical procedures, such as cholecystectomy. Debate about its real benefit over the traditional laparoscopic technique is on-going. There have been several clinical studies comparing NOTES to conventional laparoscopic surgery. However, no work has been done to compare these techniques from a Human Factors perspective. This study presents a systematic analysis describing and comparing different existing NOTES methods to laparoscopic cholecystectomy. METHODS: Videos of endoscopic/laparoscopic views from fifteen live cholecystectomies were analyzed to conduct a detailed task analysis of the NOTES technique. A hierarchical task analysis of laparoscopic cholecystectomy and several hybrid transvaginal NOTES cholecystectomies was performed and validated by expert surgeons. To identify similarities and differences between these techniques, their hierarchical decomposition trees were compared. Finally, a timeline analysis was conducted to compare the steps and substeps. RESULTS: At least three variations of the NOTES technique were used for cholecystectomy. Differences between the observed techniques at the substep level of hierarchy and on the instruments being used were found. The timeline analysis showed an increase in time to perform some surgical steps and substeps in NOTES compared to laparoscopic cholecystectomy. CONCLUSION: As pure NOTES is extremely difficult given the current state of development in instrumentation design, most surgeons utilize different hybrid methods-combination of endoscopic and laparoscopic instruments/optics. Results of our hierarchical task analysis yielded an identification of three different hybrid methods to perform cholecystectomy with significant variability among them. The varying degrees to which laparoscopic instruments are utilized to assist in NOTES methods appear to introduce different technical issues and additional tasks leading to an increase in the surgical time. The NOTES continuum of invasiveness is proposed here as a classification scheme for these methods, which was used to construct a clear roadmap for training and technology development.

Pure transvaginal ventral hernia repair in humans.

INTRODUCTION: Transvaginal natural orifice transluminal endoscopic surgery procedures are at the forefront of minimally invasive innovation, remarkable for shorter recovery times and decreased postoperative pain. We aim to demonstrate a novel technique of pure transvaginal laparoscopic ventral hernia repair in a series of patients performed in our institution. TECHNIQUE DESCRIPTION: The patient was placed in lithotomy position and steep Trendelenburg. A 2-cm transverse colpotomy incision was made and a SILS port was introduced. One 12-mm trocar and two 5-mm trocars were placed through the SILS port and standard straight laparoscopic instruments were used. An appropriately sized round mesh was deployed within a specimen retrieval bag into the peritoneal cavity. Complete anterior circumferential fixation of the mesh was achieved using an AbsorbaTack device. The colpotomy incision was closed. RESULTS: There were a total of 6 pure transvaginal ventral hernia repair procedures performed in our institution between November 2010 and February 2012. The first case was converted to an open procedure after a rectal injury was recognized and repaired. Two patients had transient urinary retention that resolved after 24 hours. One patient had vaginal wound granulation noted at 2 months postoperatively. No long-term complications or recurrences were noted with a median follow-up of 9 months. The mean operative time was 107 minutes. CONCLUSION: Our initial experience with transvaginal ventral hernia repair in humans suggests that this procedure is feasible, safe, and associated with improved cosmetic results.

"Triangle of safety": anatomic considerations in transvaginal natural orifice surgery.

BACKGROUND: The introduction of transvaginal (TV) natural orifice transluminal endoscopic surgery (NOTES) brings the loss of traditionally used cutaneous landmarks for safe peritoneal access. This video describes the use of landmarks within the posterior vaginal fornix to define a "triangle of safety" wherein the peritoneal cavity can be accessed while minimizing the risk of injury to surrounding structures. METHODS: The triangle of safety is best identified in the following way. The cervix and posterior fornix are visualized. Then an imaginary clock located at the base of the cervix is envisioned. The superior two corners of the triangle are represented by the 4 and 8 o'clock positions on this imaginary clock. Sometimes the cervix needs to be grasped and elevated anteriorly so that the inferior apex of the triangle delineated by the center of the rectovaginal fold is better visualized. RESULTS: During hybrid TV NOTES, the rectovaginal pouch of Douglas is visualized from the umbilicus, and the vaginal port can then be safely passed through the center of the triangle. It is important that the vaginal port should be angled upward, aiming toward the umbilicus to avoid injury to the rectum. During pure TV NOTES, the incision is made with electrocautery from the 5 o'clock position to the 7 o'clock position within the triangle. The peritoneum is sharply entered, and the colpotomy is dilated with the surgeons' fingers. CONCLUSIONS: The triangle of safety defines a set of landmarks between the base of the cervix and the rectovaginal fold. It allows for a safe TV access for hybrid and pure TV NOTES while minimizing the risk of injury to surrounding structures.

Pure transvaginal umbilical hernia repair.

BACKGROUND: Transvaginal natural orifice transluminal endoscopic surgery (NOTES) procedures are at the forefront of minimally invasive innovation, remarkable for shorter recovery times and decreased postoperative pain [1, 2]. Most transvaginal procedures are performed as hybrid procedures [3]. To our knowledge, this is the first video depiction of a pure transvaginal umbilical hernia repair in a human. METHODS: This is a 38-year-old woman, body mass index 36.4 kg/m(2), with a symptomatic port site hernia in the umbilical region after a previous laparoscopic cholecystectomy. The patient was positioned in stirrups in a steep Trendelenburg position. Sterilization of vaginal cavity was performed with 10 % povidone-iodine solution. A 2 cm transverse incision at the posterior fornix was made, and a SILS port (Covidien, North Haven, CT) was introduced. One 12 mm trocar and two 5 mm trocars were placed through SILS port. Standard straight laparoscopic instruments were used. A 12 cm round Parietex mesh (Covidien) was placed in a specimen retrieval bag and deployed into the peritoneal cavity. The mesh was extracted, unfolded in the abdominal cavity, and circumferentially fixated to the abdominal wall with an AbsorbaTack device (Covidien). The colpotomy incision was closed with a running absorbable suture. RESULTS: The procedure lasted 103 min and was performed on an outpatient basis. No intraoperative complications occurred. The patient was doing well and had no pain or recurrence at 2, 6, and 9 months' follow-up. CONCLUSIONS: Our initial experience with transvaginal ventral hernia repair in humans suggests that this procedure is feasible and safe. This approach may improve cosmesis and decrease the risk of future ventral hernias. Potential cons may include a longer operative time, mesh infection, and risk of visceral injury with a pure transvaginal approach. As transvaginal surgery evolves, techniques and devices will become increasingly refined to tackle these challenges.

Transvaginal natural orifice transluminal endoscopic surgery in the morbidly obese.

BACKGROUND: The objective of this study is to assess the safety and efficacy of transvaginal (TV) natural orifice transluminal endoscopic surgery (NOTES) operations in morbidly obese patients. METHODS: One hundred seven NOTES operations have been performed at our institution to date, of which 17 were completed in patients with body mass index (BMI) between 35 and 45 kg/m(2). These included 14 cholecystectomies, one appendectomy, and two ventral hernia repairs. The patients had average age of 36.2 years (range 19-62 years) and average BMI of 38.9 kg/m(2) (range 35.2-44.9 kg/m(2)). The mean number of previous abdominal operations was 1. The TV cholecystectomies were hybrid NOTES procedures, while TV appendectomy and ventral hernia repair were pure NOTES. All operations were completed with standard straight laparoscopic instruments. RESULTS: The mean operative time was 60 min for cholecystectomy, 41 min for TV appendectomy, and 90 min for ventral hernia repair. No significant difference was encountered between the operative time for NOTES cholecystectomies in obese versus nonobese (60 vs. 61 min, p = 0.86). No conversions to traditional laparoscopy or open surgery were made, and no major complications were encountered. CONCLUSIONS: NOTES is an attractive alternative to laparoscopy in female patients with morbid obesity. The procedures are safe and have short operative times, good postoperative outcomes, and improved cosmesis compared with laparoscopy.

Hierarchical task analysis of hybrid rigid scope Natural Orifice Translumenal Endoscopic Surgery (NOTES) cholecystectomy procedures.

This study shows task analysis results for the suturing task in the hybrid rigid scope Natural Orifice Translumenal Endoscopic Surgery (NOTES) cholecystectomy procedure. A hierarchical task analysis tree was constructed from the video recordings of the NOTES procedure and time analysis for the suturing subtask was performed. Results indicate that the "Pull Suture Through" subtask requires the greatest time (25.4 sec) and the "Re-bite" subtask had the highest variation (6.6 sec). Intra-rater reliability test (k = 0.68) also showed consistency of the results obtained from the video motion analysis.

Functional role of NHE4 as a pH regulator in rat and human colonic crypts.

To regulate ionic and fluid homeostasis, the colon relies upon a series of Na(+)-dependent transport proteins. Recent studies have identified a sodium/hydrogen exchanger (NHE) 4 (NHE4) protein in the gastrointestinal tract but to date there has been little description of its function. Additionally, we have previously shown that aldosterone can rapidly modulate Na(+)-dependent proton excretion via NHE proteins. In this study we examined the role of NHE4 in rat and human colonic crypts, determined the effect of aldosterone on NHE4 specifically, and explored the intracellular pathways leading to activation. Colonic samples were dissected from Sprague-Dawley rats. Human specimens were obtained from patients undergoing elective colon resections. Crypts were isolated using ethylenediaminetetraacetic acid and intracellular pH (pH(i)) changes were monitored using 2'-7'-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF). Crypts were exposed to 7 µM ethylisopropylamiloride or 400 µM amiloride, doses previously shown to inhibit NHE1 and NHE3 but allow NHE4 to remain active. Functional NHE4 activity was demonstrated in both rat and human colonic crypts. NHE4 activity was increased in the presence of 1 µM aldosterone. In the rat model, crypts were exposed to 100 µM 3-isobutyl-1-methylxanthine/1 µM forskolin and demonstrated a decrease in NHE4 activity with increased cAMP levels. No significant change in NHE4 activity was seen by increasing osmolarity. These results demonstrate functional NHE4 activity in the rat and human colon and an increase in activity by aldosterone. This novel exchanger is capable of modulating intracellular pH over a wide pH spectrum and may play an important role in maintaining cellular pH homeostasis.

Pure transvaginal appendectomy versus traditional laparoscopic appendectomy for acute appendicitis: a prospective cohort study.

OBJECTIVE: This report describes the first cohort study comparing pure transvaginal appendectomies (TVAs) to traditional 3-port laparoscopic appendectomies (LAs). METHODS: Between August 2008 and August 2010, 42 patients were offered a pure TVA. Patients who did not wish to undergo a TVA underwent a LA and served as the control group. Demographic data, operative time, length of stay, patient controlled analgesia (PCA) 12-hour-morphine utilization, complications, return to normal activity, and return to work were recorded. RESULTS: Eighteen of 40 enrolled patients underwent a pure TVA. Two patients refused to participate in this study. Mean age (TVA: 31.3 ± 2.5 years vs. LA: 28.2 ± 2.3 years, P = 0.36), mean body mass index (TVA: 23.7 ± 1.2 kg/m2 vs. LA: 23.6 ± 0.7 kg/m2, P = 0.96) mean operative time (TVA: 44.4 ± 4.5 minutes vs. LA: 39.8 ± 2.6 minutes, P = 0.38), and mean length of hospital stay (TVA: 1.1 ± 0.1 days vs. LA: 1.2 ± 0.1 days, P = 0.53) were not statistically significant. However, mean postoperative morphine-use (TVA: 8.7 ± 2.0 mg vs. LA: 23.0 ± 3.4 mg, P < 0.01), return to normal activity (TVA: 3.3 ± 0.4 days vs. LA: 9.7 ± 1.6 days, P < 0.01), and return to work (TVA: 5.4 ± 1.1 days vs. LA: 10.7 ± 1.5 days, P = 0.01) were statistically significant. One conversion in the TVA group to a LA was necessary because of inability to maintain adequate pneumoperitoneum. Four complications were observed: 1 intraabdominal abscess and 1 case of urinary retention in the TVA group; 1 early postoperative bowel obstruction and 1 case of urinary retention in the LA group. CONCLUSIONS: Pure TVA is a safe and well-tolerated procedure with significantly less pain and faster recovery compared to traditional LA.

Construct and face validity of a virtual reality-based camera navigation curriculum.

INTRODUCTION: Camera handling and navigation are essential skills in laparoscopic surgery. Surgeons rely on camera operators, usually the least experienced members of the team, for visualization of the operative field. Essential skills for camera operators include maintaining orientation, an effective horizon, appropriate zoom control, and a clean lens. Virtual reality (VR) simulation may be a useful adjunct to developing camera skills in a novice population. No standardized VR-based camera navigation curriculum is currently available. We developed and implemented a novel curriculum on the LapSim VR simulator platform for our residents and students. We hypothesize that our curriculum will demonstrate construct and face validity in our trainee population, distinguishing levels of laparoscopic experience as part of a realistic training curriculum. METHODS: Overall, 41 participants with various levels of laparoscopic training completed the curriculum. Participants included medical students, surgical residents (Postgraduate Years 1-5), fellows, and attendings. We stratified subjects into three groups (novice, intermediate, and advanced) based on previous laparoscopic experience. We assessed face validity with a questionnaire. The proficiency-based curriculum consists of three modules: camera navigation, coordination, and target visualization using 0° and 30° laparoscopes. Metrics include time, target misses, drift, path length, and tissue contact. We analyzed data using analysis of variance and Student's t-test. RESULTS: We noted significant differences in repetitions required to complete the curriculum: 41.8 for novices, 21.2 for intermediates, and 11.7 for the advanced group (P < 0.05). In the individual modules, coordination required 13.3 attempts for novices, 4.2 for intermediates, and 1.7 for the advanced group (P < 0.05). Target visualization required 19.3 attempts for novices, 13.2 for intermediates, and 8.2 for the advanced group (P < 0.05). Participants believe that training improves camera handling skills (95%), is relevant to surgery (95%), and is a valid training tool (93%). Graphics (98%) and realism (93%) were highly regarded. CONCLUSIONS: The VR-based camera navigation curriculum demonstrates construct and face validity for our training population. Camera navigation simulation may be a valuable tool that can be integrated into training protocols for residents and medical students during their surgery rotations.

Laparoscopic iliac and iliofemoral lymph node resection for melanoma.

Regional lymphadenectomy in the iliac and groin, originally devised by Basset in 1912, is performed for the treatment of melanoma metastatic to this lymphatic basin. Laparoscopic iliac node dissection may be a valuable management option because it allows performance of the same procedure as in open surgery but with significant benefits such as decreased operative morbidity due to decreased surgical trauma, less violation of the abdominal muscles or the inguinal ligament, reduced postoperative pain, and increased patient satisfaction with the cosmetic appearance. The authors' approach makes use of a laparoscopic technique to offer an alternative to traditionally described lymph node dissection for melanoma. A review of the literature showed few laparoscopic approaches in this context. Jones et al. do not perform the resection en bloc and do not address the iliofemoral lymph node dissection with a combined retroperitoneal technique such as the current authors use. Two authors in the literature use laparoscopy through a transperitoneal approach, with a piecemeal removal of nodes. Delman et al. limit their technique to the inguinal and high femoral basin alone. The video demonstrates the novel use of a laparoscopic method to harvest iliac lymph nodes in combination with a minimally invasive approach to groin dissection for metastatic melanoma. After a laparoscopic resection of these nodes, the authors deliver the iliac nodal contents through the groin using a minimally invasive approach. This approach is highly beneficial to the patient. He is able to leave the hospital significantly earlier than he would have after a traditional open procedure. He can return to his job as a car mechanic within 1 week and is metastasis free at the 9-month follow-up assessment without evidence of lymphocele formation. The authors do not believe that this technique has any significant implication for lymphocele formation compared with an open procedure because in essence, the same resection is being performed. A larger prospective series is necessary to determine lymphocele outcomes.