Robert L. Bell

The Role of Haptic Feedback in Laparoscopic Simulation Training

INTRODUCTION Laparoscopic virtual reality simulators are becoming a ubiquitous tool in resident training and assessment. These devices provide the operator with various levels of realism, including haptic (or force) feedback. However, this feature adds significantly to the cost of the devices, and limited data exist assessing the value of haptics in skill acquisition and development. Utilizing the Laparoscopy VR (Immersion Medical, Gaithersburg, MD), we hypothesized that the incorporation of force feedback in the simulated operative environment would allow superior trainee performance compared with performance of the same basic skills tasks in a non-haptic model. METHODS Ten medical students with minimal laparoscopic experience and similar baseline skill levels as proven by performance of two fundamentals of laparoscopic surgery (FLS) tasks (peg transfer and cutting drills) voluntarily participated in the study. Each performed two tasks, analogous to the FLS drills, on the Laparoscopy VR at 3 levels of difficulty, based on the established settings of the manufacturer. After achieving familiarity with the device and tasks, the students completed the drills both with and without force feedback. Data on completion time, instrument path length, right and left hand errors, and grasping tension were analyzed. The scores in the haptic-enhanced simulation environment were compared with the scores in the non-haptic model and analyzed utilizing Students t-test. RESULTS The peg transfer drill showed no difference in performance between the haptic and non-haptic simulations for all metrics at all three levels of difficulty. For the more complex cutting exercise, the time to complete the tasks was significantly shorter when force feedback was provided, at all levels of difficulty (158+/-56 versus 187+/-51 s, 176+/-49 versus 222+/-68 s, and 275+/-76 versus 422+/-220 s, at levels 1, 2, and 3, respectively, P<0.05). Data on instrument path length, grasping tension, and errors showed a trend toward a benefit from haptics at all difficulty levels, but this difference did not achieve statistical significance. CONCLUSIONS In the more advanced tasks, haptics allowed superior precision, resulting in faster completion of tasks and a trend toward fewer technical errors. In the more basic tasks, haptic-enhanced simulation did not demonstrate an appreciable performance improvement among our trainees. These data suggest that the additional expense of haptic-enhanced laparoscopic simulators may be justified for advanced skill development in surgical trainees as simulator technology continues to improve.

Reproductive considerations and pregnancy after bariatric surgery: current evidence and recommendations.

Obesity has reached epidemic proportions in the USA. Bariatric surgery is an important and increasingly utilized treatment option for morbid obesity refractory to medical therapy. Approximately half of all bariatric surgery patients are reproductive-aged women and, thus, represent a unique patient population with specific concerns. This manuscript focuses on issues of increased postoperative fertility, nutritional monitoring and supplementation, safety of pregnancy after bariatric surgery, and effect of pregnancy on postoperative weight loss. Current recommendations regarding management of patients both before and during pregnancy are provided. In addition, we highlight areas where more research on this issue is needed and advocate for a multidisciplinary approach to patient care.

Surgical Treatment of Achalasia: Current Status and Controversies

Objective: To review the current management of achalasia, and the controversies regarding the different treatment options. Methods: A review of the literature was performed. The key words used were esophageal achalasia, Heller myotomy, endoscopic balloon dilatation, laparoscopic Heller myotomy, and fundoplication. Results: Patients who fail medical therapy (e.g. pharmacologic therapy, botulinum toxin, balloon dilatation) should be considered for surgical therapy for the management of achalasia. Currently, numerous surgical procedures exist for the treatment of achalasia (transabdominal cardiomyotomy, thoracoscopic or open transthoracic cardiomyotomy, and laparoscopic Heller myotomy with an antireflux procedure). Conclusions: Laparoscopic Heller myotomy is generally accepted as the operative procedure of choice for achalasia. However, controversy exists as to whether a concomitant antireflux procedure is necessary, and if so, what type should be performed. Given the deleterious effects of postoperative reflux, and the facility of including an antireflux procedure at the time of the myotomy, there is merit in undertaking an antireflux procedure at the time of the laparoscopic Heller myotomy.

Laparoscopic treatment of fulminant ulcerative colitis.

Background: The complexity and risks of the surgical treatment of ulcerative colitis are greater in patients with fulminant disease. Subtotal colectomy is frequently offered to such patients to control acute disease and restore immunological and nutritional status prior to a restorative procedure. The role of laparoscopy in this setting is poorly defined. Methods: The records of 18 patients with poorly controlled fulminant colitis on aggressive immunosuppressive therapy who underwent laparoscopic subtotal colectomy were reviewed. Results: Postoperative complications occurred in six patients (33%). Postoperative length of stay was 5.0 ± 0.3 days vs 8.8 ± 1.8 days (p<0.05) for a group of six patients who had undergone open subtotal colectomy for the same indications. Systemic steroids were withdrawn in all patients, and 17 patients subsequently underwent proctectomy and pelvic pouch construction. Conclusions: The relatively high morbidity rate in these patients is likely related to their compromised status at the time of surgery. Laparoscopic subtotal colectomy in patients with fulminant ulcerative colitis allows for earlier hospital discharge, facilitates subsequent pelvic pouch, construction, and provides an excellent alternative to conventional two- and three-stage surgical treatment.

Chest Tube Removal: End-inspiration or End-expiration?

BACKGROUND Recurrent pneumothorax is the most significant complication after discontinuation of thoracostomy tubes. The primary objective of the present study was to determine which method of tube removal, at the end of inspiration or at the end of expiration, is associated with a lesser risk of developing a recurrent pneumothorax. A secondary objective was to identify potential risk factors for developing recurrence. METHODS A prospective study of 102 chest tubes in 69 trauma patients (1.5 tubes per patient) randomly assigned to removal at the end of inspiration (n = 52) or the end of expiration (n = 50). RESULTS Recurrent pneumothorax or enlargement of a small but stable pneumothorax was observed after the removal of four chest tubes in the end-inspiration group (8%) and after discontinuation of three chest tubes (6%) in the end-expiration group (p = 1.0). Of those, only two tubes in the end-inspiration group and 1 tube in the end-expiration group required repeat closed thoracostomy. Multiple factors were analyzed that did not adversely affect outcome. These included patient age, Injury Severity Score, Revised Trauma Score, mechanism of injury, hemothorax, thoracotomy, thoracostomy, previous lung disease, chest tube duration, the presence of more than one thoracostomy tube in the same hemithorax, or a small (but stable) pneumothorax at the time of tube removal. CONCLUSIONS Discontinuation of chest tubes at the end of inspiration or at the end of expiration has a similar rate of post-removal pneumothorax. Both methods are equally safe.

Use of mobile low-bandwith telemedical techniques for extreme telemedicine applications

BACKGROUND Telemedicine is traditionally associated with the use of very expensive and bulky telecommunications equipment along with substantial bandwidth requirements (128 kilobytes per second [kbps] or greater). Telementoring is an educational technique that involves real-time guidance of a less experienced physician through a procedure in which he or she has limited experience. This technique has been especially dependent on the aforementioned requirements. Traditionally, telemedicine and telementoring have been restricted to technically sophisticated sites. The telemedicine applications through the existing telecommunication infrastructure has not been possible for underdeveloped parts of the world. STUDY DESIGN Telemedicine and telementoring were applied using low-bandwidth mobile telemedicine applications to support a mobile surgery program in rural Ecuador run by the Cinterandes Foundation and headed by Edgar Rodas, MD. A mobile operating room traveled to a remote region of Ecuador. Using a laptop computer equipped with telemedicine software, a videoconferencing system, and a digital camera, surgical patients were evaluated and operative decisions were made over low-bandwidth telephone lines. Similarly, surgeons in the mobile unit in Ecuador were telementored by an experienced surgeon located thousands of miles away at Yale University School of Medicine. RESULTS Five preoperative evaluations were conducted from Sucua to Cuenca, Ecuador, with excellent clinical correlation. Additionally, a laparoscopic cholecystectomy was successfully telementored from the department of surgery at Yale University School of Medicine to the mobile surgery unit in Ecuador. The telementored surgery was performed using a telephone line with a baud rate of 12 kbps. CONCLUSIONS Mobile, low-bandwidth telemedicine applications used in the proper technical and clinical algorithms can be very effective in supporting remote health care delivery efforts. Advantages of such applications include increased cost-effectiveness by limiting travel, expanding services to patients, and increased patient quality assurance.

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/m2. 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.

Designing and validating a customized virtual reality-based laparoscopic skills curriculum.

OBJECTIVE We developed and instituted a laparoscopic skills curriculum based on a virtual reality simulator, LapSim (Surgical Science, Göteborg, Sweden). Our goal was to improve basic skills in our residents. The hypothesis of this study is that performance in our course will differentiate levels of experience in the training program, establishing construct validity for our curriculum. DESIGN We designed a novel curriculum that consisted of 17 practice modules and a 7-part examination. All residents who completed the curriculum successfully were included in this study. Performance to complete the examination was analyzed. Data were stratified by level of training. SETTING University surgical skill training laboratory. PARTICIPANTS In all, 29 residents of all levels of training and 3 attending surgeons completed the curriculum. RESULTS The average number of practice repetitions required was 243. To complete the examination component, junior residents (R1-R3) required more repetitions than senior residents (R4, R5), 28.3 versus 13.9, respectively (p < 0.002). Tasks on camera and instrument navigation as well as coordination did not reveal significant differences. The complex grasping task demonstrated significant differences in repetitions required for each level of training: 19.5 attempts for R1, 17.2 for R2, 13 for R3, 8.5 for R4, and 3 for R5 (p < 0.04). The 2 cutting drills, which required precise use of the left hand, required 7.9 repetitions for junior residents versus 2.7 for senior residents (p < 0.009). A clip application drill differentiated among junior residents with 39.4, 19.8, and 8.5 repetitions required for R1, R2, and R3, respectively (p < 0.05). Senior residents performed equivalent to attendings on this drill. A lifting and grasping drill differentiates among junior residents, senior residents, and attendings (p < 0.03). CONCLUSIONS Individual performance in our curriculum correlates with the level of training for many drills, which establishes construct validity for this curriculum. Noncontributory drills may need to be revised or removed from the curriculum. Successful completion of this curriculum may lead to improved resident technical performance.

Defining Surgical Therapy for Pseudomembranous Colitis With Toxic Megacolon

Background Pseudomembranous colitis has increased in incidence and severity over the past 10 years. Toxic megacolon is a rare but reported presentation of severe pseudomembranous colitis. This article reviews the reported cases of Clostridium difficile with toxic megacolon in the literature and introduces an additional case that underscores the importance of early diagnosis in guiding appropriate therapy. Methods A systematic review of the literature was performed to identify previous reports of pseudomembranous colitis presenting with toxic megacolon, and the outcomes of each of these cases was analyzed. The review was focused on atypical presentations in immunocompromised patients. Results Seventeen cases of C. difficile colitis presenting as toxic megacolon were identified. The overall mortality rate was 50% (9/18). Fifteen patients underwent surgery with an associated mortality rate of 50%. Thirteen patients had a subtotal colectomy. Seven of the patients (39%) were taking immunosuppressant medications, and 5 (28%) patients presented with atypical symptoms. Three (76%) of those were immunosuppressed. In several cases, failure to make an early diagnosis of C. difficile colitis resulted in a worse outcome because appropriate therapy was delayed. Conclusions Toxic megacolon is well-established as an unusual presentation of C. difficile colitis. These patients are less likely to present with typical symptoms such as diarrhea or typical risk factors like recent administration of antibiotics, so diagnosis can be a challenge. A patient presenting with toxic megacolon without a history of inflammatory bowel disease should be assumed to have C. difficile colitis until proven otherwise, and medical or surgical therapy administered accordingly.

Metabolic consequences of bariatric surgery.

Obesity has gained prominence as a main cause of preventable illness and death in the developed world. Surgical therapy for obesity is extremely effective in terms of weight reduction and amelioration of comorbidities. Bariatric procedures are not simply cosmetic operations, however, and involve considerable manipulation of the gastrointestinal tract to induce weight loss. The metabolic consequences of these procedures can be severe if not preempted with relatively simple postoperative precautions on the part of the patient and surgeon. Modern bariatric procedures are much safer than their predecessors, but nutritional and metabolic changes must be anticipated and compensated to fully realize the benefits of surgery. The metabolic consequences of the now outdated jejunoileal bypass, and the more modern Roux-Y gastric bypass, gastroplasty, and biliopancreatic diversion, are presented here, along with specific considerations of patient populations.