Video. Chopstick surgery: a novel technique enables use of the Da Vinci Robot to perform single-incision laparoscopic surgery.

INTRODUCTION: Single-incision laparoscopic surgery (SILS) is limited by the coaxial arrangement of the instruments. A surgical robot with "wristed" instruments could overcome this limitation but the "arms" collide when working coaxially. This video demonstrates a new technique of "chopstick surgery," which enables use of the robotic arms through a single incision without collision. METHODS: Experiments were conducted utilizing the da Vinci S® robot (Sunnyvale, CA) in a porcine model with three laparoscopic ports (12 mm, 2-5 mm) introduced through a single "incision." Pilot work conducted while performing Fundamentals of Laparoscopic Surgery (FLS) tasks determined the optimal setup for SILS to be a triangular port arrangement with 2-cm trocar distance and remote center at the abdominal wall. Using this setup, an experienced robotic surgeon performed a cholecystectomy and nephrectomy in a porcine model utilizing the "chopstick" technique. The chopstick arrangement crosses the instruments at the abdominal wall so that the right instrument is on the left side of the target and the left instrument on the right. This arrangement prevents collision of the external robotic arms. To correct for the change in handedness, the robotic console is instructed to drive the "left" instrument with the right hand effector and the "right" instrument with the left. RESULTS: Both procedures were satisfactorily completed with no external collision of the robotic arms, in acceptable times and with no technical complications. This is consistent with results obtained in the box trainer where the chopstick configuration enabled significantly improved times in all tasks and decreased number of errors and eliminated instrument collisions. CONCLUSION: Chopstick surgery significantly enhances the functionality of the surgical robot when working through a small single incision. This technique will enable surgeons to utilize the robot for SILS and possibly for intraluminal or transluminal surgery.

Leaders by example: Best practices and advice on establishing a state-of-the art surgical simulation center that optimizes available resources.

BACKGROUND: The role of simulation-based education continues to expand exponentially. To excel in this environment as a surgical simulation leader requires unique knowledge, skills, and abilities that are different from those used in traditional clinically-based education. METHODS: Leaders in surgical simulation were invited to participate as discussants in a pre-conference course offered by the Association for Surgical Education. Highlights from their discussions were recorded. RESULTS: Recommendations were provided on topics such as building a simulation team, preparing for accreditation requirements, what to ask for during early stages of development, identifying tools and resources needed to meet educational goals, expanding surgical simulation programming, and building educational curricula. CONCLUSION: These recommendations provide new leaders in simulation with a unique combination of up-to-date best practices in simulation-based education, as well as valuable advice gained from lessons learned from the personal experiences of national leaders in the field of surgical simulation and education.

Changing attitudes toward endolumenal therapy.

BACKGROUND: As with new laparoscopic techniques, the ability to convince surgeons and gastroenterologists to embrace endolumenal techniques and the additional training required to perform the new procedures will correlate with how rapidly endolumenal therapies are adopted. The authors measured their ability to change attitudes among surgeons, who may or may not perform endoscopy as a part of their practice, toward endolumenal therapies. METHODS: As part of the endoluminal therapy postgraduate course presented at the annual Society of American Gastrointestinal Endoscopic Surgeons (SAGES) meeting in Ft. Lauderdale, Florida 2005, experts presented current literature and data on new endolumenal techniques. The participants, primarily of surgeons, were polled electronically about a number of case scenarios before and after their presentation. Each scenario was relevant to the topic presented and chosen to reflect potentially controversial disease processes with traditional or endolumenal treatment options. The responses were collected in real time and displayed to course participants. RESULTS: A panel of 10 experts presented data on a range of endolumenal therapies including endolumenal treatment for gastroesophageal reflux disease (GERD), endoscopic stenting, endoscopic treatments in bariatric surgery, intraoperative endoscopy, endoscopic mucosal resection (EMR), transanal endoscopic microsurgery (TEM), mucosal ablation for Barrett's esophagus, intralumenal resection, translumenal endoscopic surgery, and how to educate surgeons in new endolumenal techniques. Demographic data showed that 83.6% of the participants performed endoscopy as part of their practice. A comparison with traditional surgical options showed a statistically significant positive attitude change (p < 0.05) toward adoption of most endolumenal techniques after expert presentation. Only EMR and TEM did not show a statistically significant change in the participants' willingness to adopt these techniques. There was no significant change in the attitudes of how best to train surgeons. After presentation of the training options, 76% of the respondents believed that these techniques should be taught in residency. CONCLUSIONS: The education of surgeons in new endolumenal therapeutic techniques can have a significant impact in terms of changing practice attitudes and may accelerate adoption of new endoscopic techniques.

The role of the surgeon in the evolution of flexible endoscopy.

Several cultures, including the Egyptians, Greeks, Romans, and Arabs, made attempts to view accessible human body cavities using a variety of instruments such as spatulas and specula. The first endoscope was created in 1806 when Phillip Bozzini, a German-born urologist, constructed the lichtleiter, which used concave mirrors to reflect candlelight through an open tube into the esophagus, bladder, or rectum. Maximilian Carl-Friedrich Nitze, another German urologist, produced the first usable cystoscope in 1877 by using series of lenses to increase magnification. He was also the first to place light inside the organ of interest to aid visualization. In 1880 Mikulicz made the first gastroscope using a system similar to Nitze's cystoscope. Modern endoscopy was born with the introduction of the fiberoptic endoscope in the late 1950s. Over the ensuing 50 years endoscopy revolutionized many aspects of the surgeon's practice. Endoscopy can now be used to diagnose and often treat gastrointestinal cancer, hemorrhage, obstruction, and inflammatory conditions. This review was initiated by the SAGES Flexible Endoscopy Committee to chronicle the role of the surgeon in the development and introduction of flexible endoscopy into clinical practice, historically and in contemporary surgery. Flexible endoscopy evolved out of surgeons' need to overcome diagnostic and therapeutic challenges. There have been many recent technological advances that facilitate endoluminal therapies, and flexible endoscopy is now traversing new ground. Surgeons have been major contributors in the development of all aspects of endoscopy. There is a continually expanding list of therapeutic options available to patients. The difficult questions of which procedure, on which patient, and when can be answered best by the surgeon versed in endoscopic, laparoscopic, and open surgical techniques.

Endoscopic ablation of intestinal metaplasia containing high-grade dysplasia in esophagectomy patients using a balloon-based ablation system.

BACKGROUND: This study aimed to determine the optimal treatment parameters for the ablation of intestinal metaplasia (IM) containing high-grade dysplasia (HGD) using a balloon-based ablation system for patients undergoing esophagectomy. METHODS: Immediately before esophagectomy, patients underwent ablation of circumferential segments of the esophagus containing IM-HGD using the HALO360 system. The treatment settings were randomized to 10, 12, or 14 J/cm2 for two, three, or four applications. After esophagectomy, multiple sections from ablation zones were microscopically evaluated. Histologic end points included maximum ablation depth (histologic layer) and complete ablation of all IM-HGD (yes/no). RESULTS: Eight men with a mean age of 57 years (range, 45-71 years) were treated, and 10 treatment zones were created. There were no device-related adverse events. At resection, there was no evidence of a transmural thermal effect. Grossly, ablation zones were clearly demarcated sections of ablated epithelium. The maximum ablation depth was the lamina propria or muscularis mucosae. The highest energy (14 J/cm2, 4 applications) incurred edema in the superficial submucosa, but no submucosa ablation. Complete ablation of IM and HGD occurred in 9 of 10 ablation zones (90%), defined as complete removal of the epithelium with only small foci of "ghost cells" representing nonviable, ablated IM-HGD and demonstrating loss of nuclei and cytoarchitectural derangement. One focal area of viable IM-HGD remained at the margin of one ablation zone (12 J/cm2, 2 applications) because of incomplete overlap. CONCLUSION: Complete ablation of IM-HGD without ablation of submucosa is possible using the HALO360 system. Ablation depth is dose related and limited to the muscularis mucosae. In one patient, small residual foci of IM-HGD at the edge of the ablation zone were attributable to incomplete overlap, which can be avoided. This study, together with nonesophagectomy IM-HGD trials currently underway, will identify the optimal treatment parameters for IM-HGD patients who would otherwise undergo esophagectomy or photodynamic therapy.

Endoluminal and transluminal surgery: current status and future possibilities.

The field of minimally invasive surgery has seen tremendous growth since the first laparoscopic cholecystectomy was performed in 1987. The key question is not how successful these techniques are currently, but rather where may they lead in the future? New technologies promise to usher in an era of even less invasive procedures. The terms being coined in the literature include "incisionless," "endoluminal," "transluminal," and "natural orifice" transluminal endoscopic surgery. These techniques certainly have the potential to become the next wave of minimally invasive procedures. A recent editorial in Surgical Endoscopy by Macfadyen and Cuschieri highlighted the ongoing developments in endoscopic surgery and stressed the critical importance of surgeons being involved in future applications and permutations of these techniques [1]. There are early signs of such involvement. The work of numerous investigators in the field was presented recently at the 2005 Digestive Disease Week. The American Society for Gastrointestinal Endoscopy and the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES), in collaboration with the American College of Surgeons, recently organized a postgraduate course in endoluminal therapy at the spring 2005 meeting held in Hollywood, Florida. The course is being offered again at the 2006 SAGES annual meeting. Similar courses are being offered at other regional and national meetings. This review attempts to highlight some of the available and evolving endoluminal therapies reviewed at that forum, including techniques for the management of gastroesophageal reflux disease, endoscopic mucosal resection, endoluminal bariatric surgery, transanal endoscopic microsurgery, and transgastric endoscopic surgery, as well as new technologies and possible future directions in luminal access surgery.

Thin-layer ablation of human esophageal epithelium using a bipolar radiofrequency balloon device.

BACKGROUND: The goal of this study was to determine the optimal treatment parameters for the ablation of human esophageal epithelium using a balloon-based bipolar radiofrequency (RF) energy electrode. METHODS: Immediately prior to esophagectomy, subjects underwent esophagoscopy and ablation of two separate, 3-cm long, circumferential segments of non-tumor-bearing esophageal epithelium using a balloon-based bipolar RF energy electrode (BARRX Medical, Inc., Sunnyvale, CA, USA). Subjects were randomized to one of three energy density groups: 8, 10, or 12 J/cm2. RF energy was applied one time (1x) proximally and two times (2x) distally. Following resection, sections from each ablation zone were evaluated using H&E and diaphorase. Histological endpoints were complete epithelial ablation (yes/no), maximum ablation depth, and residual ablation thickness after tissue slough. Outcomes were compared according to energy density group and 1x vs 2x treatment. RESULTS: Thirteen male subjects (age, 49-85 years) with esophageal adenocarcinoma underwent the ablation procedure followed by total esophagectomy. Complete epithelial removal occurred in the following zones: 10 J/cm2 (2x) and 12 J/cm2 (1x and 2x). The maximum depth of injury was the muscularis mucosae: 10 and 12 J/cm2 (both 2x). A second treatment (2x) did not significantly increase the depth of injury. Maximum thickness of residual ablation after tissue slough was only 35 microm. CONCLUSIONS: Complete removal of the esophageal epithelium without injury to the submucosa or muscularis propria is possible using this balloon-based RF electrode at 10 J/cm2 (2x) or 12 J/cm2 (1x or 2x). A second application (2x) does not significantly increase ablation depth. These data have been used to select the appropriate settings for treating intestinal metaplasia in trials currently under way.

Esophageal mucosal blood flow: a central role for calcitonin gene-related peptide.

BACKGROUND: Esophageal mucosal blood flow is a dynamic phenomenon dependent on luminal content. Reactive hyperemia, likely a factor in mucosal protection, follows luminal exposure to noxious substances, including bile. The mediators of this response are unknown, although the likelihood is that visceral afferent nerves play a major role. The purpose of this study was to determine whether substance P, calcitonin gene-related peptide (CGRP), or adenosine could mediate this reactive blood flow response. METHODS: Esophageal mucosal blood flow was studied in a rabbit model with the radiolabeled microsphere technique. The effect of intraarterial infusion of CGRP and substance P and intravenous adenosine was studied. Subsequently, the hyperemic response to luminal deoxycholate was measured in the presence of antagonists to CGRP, substance P, and adenosine. Immunohistochemical studies were performed to determine the distribution of CGRP and substance P in the esophagus. RESULTS: CGRP proved to be a potent stimulus to mucosal blood flow. The presence of a CGRP antagonist reduced mucosal blood flow at baseline and after exposure to deoxycholate. Antagonists to substance P and adenosine had no effect on baseline and deoxycholate-stimulated blood flow. CONCLUSIONS: CGRP is likely a major mediator involved in the regulation of esophageal mucosal blood flow.

Impact of upper endoscopic survey during percutaneous endoscopic gastrostomy tube placement.

BACKGROUND: No consensus exists concerning the utility of a full diagnostic upper endoscopy during percutaneous endoscopic gastrostomy (PEG) tube placement. We evaluate the effect of a complete survey on identifying and treating unsuspected gastrointestinal pathology. METHODS: During a 10-year period (1990-2000), 1,706 patients underwent attempted PEG tube placement by five different surgical endoscopists at one institution. A complete survey of the esophagus, stomach, and proximal duodenum was attempted in all cases. Endoscopic findings and recommendations were recorded in a computerized log and patient charts. Pathology results were obtained from a computerized pathology database and patient charts. RESULTS: Placement of a PEG tube was successful in 97%, and a full survey was possible in 99% of the cases. Pathologic findings were found in 38% of the surveyed patients (esophagus, 7%; stomach, 24%; duodenum, 7%). One group with gastrointestinal polyps or gastric ulcers (5.7%) was identified as possible candidates for endoscopic intervention. In 30% of this group (1.8% of the total) a biopsy was performed, or bleeding was treated endoscopically. In a second group pathology was identified in the duodenum (6.4%) that would not have been recognized without a full survey. These duodenal findings resulted in a recommendation for treatment change in 38% of this group (2.4% of the total). CONCLUSIONS: Upper endoscopic survey before PEG tube placement showed a significant amount of unsuspected gastrointestinal pathology. Findings requiring biopsy, immediate treatment, or a change in medical treatment occurred in 4.2% of the cases, and these findings did not prevent PEG tube placement in any patient.

Laparoscopic right donor nephrectomy: technique and comparison with left nephrectomy.

BACKGROUND: Laparoscopic donor nephrectomy (LDN) preferentially involves the left kidney to optimize vessel length, but occasionally, right nephrectomy is preferred. Right LDN differs markedly in anatomic relations and the need for a fourth port. This retrospective study compares donor outcomes and graft function of right and left LDN and describes the technique. METHODS: Consecutive patients undergoing right LDN from March 26, 1996 to December 31, 2000 were compared with those undergoing left LDN. Age, height, weight, body mass index, creatinine, creatinine clearance, operative time, warm ischemia time, analgesic requirements, serial postoperative creatinine, time to diet resumption, and hospital stay were compared. A second cohort matched for age, gender, race, and temporal left LDN also were compared with the group undergoing right LDN. RESULTS: No significant differences were found for any of the parameters measured. CONCLUSION: This study demonstrates that despite substantial differences in the procedures, donor outcome and graft survival are similar for right and left LDN.

Short-term endobiliary stenting results in chronic inflammation of the porcine extrahepatic biliary system.

This study reports the histologic changes seen in the biliary ductal system and pancreas as a result of endobiliary stenting. Ten mini pigs underwent endoscopic placement of suprapapillary endobiliary stents. The animals were killed and the liver, biliary tree, and pancreas were resected en bloc and prepared for histologic examination. Endobiliary stenting was found to result in significant chronic inflammation in the biliary system within 4 weeks of stent placement. These changes were present throughout the entire extrahepatic biliary ductal system and persisted throughout the 15-week study period. There was no significant acute inflammation in the biliary tree nor acute or chronic inflammation in the pancreatic duct. Further study is indicated to determine whether these changes will result in fibrosis and stricture.

Ultrasound-directed percutaneous endoscopic cyst-gastrostomy for the treatment of a pancreatic pseudocyst.

The incidence of pseudocysts in patients with chronic pancreatitis ranges from 20-40%. Unlike pseudocysts associated with acute pancreatitis, these do not usually resolve spontaneously. Traditionally, these cysts were drained surgically. More recently, however, they have been successfully managed with endoscopic drainage. This report reviews the history and results of nonsurgical pseudocyst management and describes a case of drainage obtained using an alternative method of ultrasound-directed percutaneous endoscopic cyst-gastrostomy.

Effects of granulocyte colony stimulating factor in a nonneutropenic rodent model of Escherichia coli peritonitis.

Despite improved antimicrobials and advances in caring for critically ill patients, mortality from sepsis is still unacceptably high. Upregulation of the cellular immune system is one strategy for decreasing mortality in subjects with severe sepsis, which appears to be promising. Granulocyte colony stimulating factor (G-CSF) has been used successfully to decrease mortality in neutropenic subjects with sepsis. In this study, we have investigated whether pretreatment with G-CSF decreases mortality in non-neutropenic rodents with lethal Escherichia coli peritonitis. We implanted agar pellets impregnated with 5 x 10(8) cfu of Escherichia coli into the peritoneal cavities of rats pretreated with 50 micrograms/kg of G-CSF or an equal volume of 5% dextrose in water (D5W). Survival of these animals increased from 38 to 78% with G-CSF pretreatment. We also demonstrated an 11-fold increase in the number of polymorphonuclear leukocytes (PMNs) in animals treated with G-CSF. This increase in cells was seen initially only in the peripheral circulation. Twenty-four hours after induction of peritonitis, however, there was a three-fold greater increase in number of PMNs recovered from the peritoneal cavities of animals pretreated with G-CSF as compared to those treated with D5W. PMNs recovered from the peritoneal cavities of these animals had significantly elevated bactericidal activity (74% killing vs 53% killing) as compared to those cells recovered from the peritoneal cavities of control animals. These results indicate that G-CSF pretreatment improves survival of non-neutropenic animals with lethal Escherichia coli peritonitis by enhancing the cellular arm of the immune response.

Nitric oxide regulates basal but not capsaicin-, CGRP-, or bile salt-stimulated rabbit esophageal mucosal blood flow.

BACKGROUND/AIMS: Esophageal mucosal blood flow is a dynamic phenomenon that is altered by luminal content that probably represents an important intrinsic method of defense. This study investigated the role played by endogenous nitric oxide in the regulation of esophageal mucosal blood flow at rest and in response to luminal capsaicin, a specific stimulant for visceral afferent nerves, as well as calcitonin gene-related peptide, and the bile salt deoxycholate. METHODS: The L-arginine analog L-NAME was used to block nitric oxide synthesis. Radiolabeled microspheres were used to measure blood flow in a well-characterized rabbit model. Phenylephrine was used to mimic the hemodynamic effects of L-NAME to show the specificity of positive findings. RESULTS: Administration of L-NAME led to a significant reduction in mucosal blood flow at rest, an effect that was not shared by phenylephrine. The blood flow responses to luminal capsaicin, intra-arterial calcitonin gene-related peptide (CGRP), and luminal deoxycholate, however, were not diminished in the presence of L-NAME. CONCLUSIONS: Although nitric oxide may play a role in the maintenance of normal resting esophageal mucosal blood flow, the reactive responses to luminal capsaicin, luminal deoxycholate, and intra-arterial CGRP are not nitric oxide dependent.

Nitric oxide mediates the blood flow response to intravenous adenosine in the rabbit.

The objective of this study was to determine if nitric oxide mediates the effects of exogenously administered adenosine on peripheral blood flow. An intravenous infusion of adenosine (1.0 mumol/kg/min) into male New Zealand white rabbits caused an increase in blood flow, measured using radiolabeled microspheres, throughout the gastrointestinal tract, as well as in the heart and kidneys. Prior administration of nitro-L-arginine methyl ester (L-NAME) 10 mg/kg i.v. completely blocked the hyperemic effect of adenosine on all organs studied. Administration of L-arginine (300 mg/kg bolus and 50 mg/kg/min infusion) together with L-NAME restored the hyperemic effect of adenosine. This phenomenon was specified to the L-arginine/nitric oxide pathway in that a similar pressor response induced by phenylephrine (1.5 micrograms/kg/min) did not block the effects of adenosine. We conclude that the peripheral vasodilator response to intravenously administered adenosine in the rabbit is mediated by nitric oxide.

Pretreatment with allopurinol diminishes pancreatography-induced pancreatitis in a canine model.

BACKGROUND: The role of oxygen-derived free radicals in the pathogenesis of pancreatitis has been supported by data from previous studies using animal models. This study was conducted to determine whether prophylaxis with the xanthine oxidase inhibitor allopurinol would decrease the incidence and severity of pancreatography-induced pancreatitis in a canine model. METHODS: Thirty-two dogs were randomized to receive either placebo or oral allopurinol 1 hour before the procedure. A laparotomy and duodenotomy were performed and a pancreatogram was obtained. Postoperatively, pancreatic enzymes were drawn for 5 days. The animals were then euthanized, and the pancreas was weighed and evaluated histologically. RESULTS: The histologic incidence of pancreatitis was significantly reduced in the allopurinol pretreatment group (6.7%) as compared with the placebo group (41.2%, p < 0.01). A significant decrease in postoperative serum amylase levels among dogs pretreated with allopurinol was also noted. A similar trend was observed in lipase levels. The pancreas weight index was decreased in the allopurinol pretreatment group as well (control = 0.00246 vs. allopurinol = 0.00195, p < 0.02). CONCLUSIONS: Pretreatment with oral allopurinol decreases the incidence of pancreatography-induced pancreatitis. These results support the role of xanthine oxidase inhibitors in the prevention of endoscopic retrograde cholangiopancreatography-induced pancreatitis.

Effect of growth factors on cell proliferation and epithelialization in human skin.

The failure of chronic wounds to heal remains a major medical problem. Recent studies have suggested an important role for growth factors in promoting wound healing. We investigated the mitogenic effect of basic fibroblast growth factor (FGF), insulin-like growth factor-1 (IGF-1), and epidermal growth factor (EGF), comparing their effects with those of media alone (MEM) in a human skin explant model. A stable organ culture system for maintaining the histologic structure of human epidermis for 10 days in vitro was developed. DNA synthesis was measured on Days 1, 3, and 7 of organ culture using [3H]thymidine ([3H]thy) uptake and expressed as cpm/mg dry weight (mean +/- SEM). FGF, IGF-1, and EGF were each capable of stimulating [3H]thy uptake on Day 1 of culture (2372 +/- 335 FGF, 2226 +/- 193 IGF-1, 4037 +/- 679 EGF vs 1108 +/- 70 MEM, P < 0.05). IGF-1 and EGF also stimulated [3H]thy uptake on Days 3 and 7 of culture. The organ culture system was further employed to observe epidermal outgrowth. Longest keratinocyte outgrowth from the explant periphery (simulating epithelial regeneration from the wound edge) was observed on Day 7. EGF resulted in maximum stimulation of epithelial outgrowth (440 +/- 80 microns), followed by FGF (330 +/- 56 microns), IGF-1 (294 +/- 48 microns), and MEM (189 +/- 50 microns). We postulate, therefore, that FGF, IGF-1, and EGF are important mitogens for wound healing and that EGF in particular is capable of stimulating epithelialization.(ABSTRACT TRUNCATED AT 250 WORDS)