Endoscopic horizon stabilization in natural orifice translumenal endoscopic surgery: a randomized controlled trial.

BACKGROUND: Spatial orientation in natural orifice translumenal endoscopic surgery (NOTES) has been identified as a potential barrier to clinical application. We aim to evaluate a triaxial inertial sensor and software that automatically corrects any movements on the roll axis of the flexible endoscope, allowing for stabilization of the image horizon during NOTES operations in a randomized controlled trial. METHODS: A total of 18 participants (11 surgeons/7 gastroenterologists) performed a transgastric task in the ELITE simulator, which included navigation to the appendix and gallbladder, diathermy of the appendix base and gallbladder fossa, and clipping of the cystic duct using a single-channel gastroscope. Each participant performed the task twice with randomization to horizon stabilization occurring at the second attempt. The primary end point was change in overall performance (time taken and errors made) between the first and second attempt, and secondary end points were absolute performances in the second attempt and subjective evaluation. RESULTS: Without horizon stabilization, there was a median improvement of 42.4% in time taken and 38% in number of errors made from the first to the second attempt; however, with the software turned on, there was a statistically significant deterioration of 4.9% (P = .038) in time taken and an increase in errors made of 183% (P = ns). CONCLUSIONS: Although the software corrects the view to that preferred during surgery, the endoscopic control mechanism as well as the exit point of the instrument are altered in this process, leading to a deterioration of overall performance. Potential solutions include deploying intermittent horizon stabilization or using a robotic interface to achieve fully aligned perceptual-motor control.

Solo-surgical laparoscopic cholecystectomy with a joystick-guided camera device: a case-control study.

BACKGROUND: This study aimed to evaluate the implementation of a joystick-controlled camera holder (Soloassist; Actormed, Barbing, Germany) in laparoscopic cholecystectomy as so-called solo-surgery compared with the standard operation. METHODS: Of the 123 patients included in this study, 63 underwent laparoscopic cholecystectomy using the Soloassist system and were compared with 60 patients who underwent laparoscopic cholecystectomy with human assistance. The two groups did not differ significantly in terms of age, sex, body mass index, or American Society of Anesthesiology classification. The surgeons were divided into those highly experienced and those experienced with the new camera holder. The operation times were measured, including setup and dismantling of the system. The assessment also included complications, postoperative hospital stay, measurement of human resources in terms of personnel/minutes/operation, and subjective evaluation of the camera-guiding device by the surgeons. RESULTS: The hospital stay and operation-related complications were not enhanced in the Soloassist group. The differences in core operation time (p = 0.008) and total operating time (p = 0.001) significantly favored the human assistant. Whereas the absolute duration of surgery was longer, the relative operating time (in personnel/minutes/operation) was significantly shorter (p < 0.001). In 4.8 % of the cases, the operation could not be performed completely with the camera-holding device. Clinically relevant postoperative complications did not occur. The experience of the surgeons did not differ significantly. The subjective evaluation regarding handling, image quality, effort, and satisfaction demonstrated high acceptance of the Soloassist system. CONCLUSIONS: The camera-guiding device can be implemented without increased complications. The Soloassist system is safe and can be operated even by colleagues without system experience. All the surgeons rated their satisfaction with the system as very good to excellent. Although the operating times were longer than with the standard camera guidance, the absolute overall staff time was reduced.

Therapeutic peritoneal lavage with warm saline solution as an option for a critical hypothermic trauma patient.

INTRODUCTION: In this paper, we present the case of a 63-year-old woman, who was found in her flat lying unconscious on the floor for an unknown time. At the time of admission, her core temperature was 24 °C and ventricular fibrillation was detected on the electrocardiogram (ECG). Because of the unstable conditions, the persistent nonperfusing cardiac rhythm and the dramatically inhibited coagulation cascade, a peritoneal lavage connected to a rapid infuser was performed for rewarming, instead of using a transportable heart-lung machine and a haemodialysis device. After a prolonged cardiopulmonary resuscitation (CPR), the patient could be transferred to the intensive care unit (ICU) in a stable condition. After 40 days in the ICU, recovery was fast, and another month of treatment later, she could be discharged back home without any discomfort. CONCLUSION: This report illustrates the successful use of the peritoneal lavage for rewarming a severely hypothermic patient without any extracorporeal rewarming device. Furthermore, it can be used in nearly every hospital if the necessary equipment is affordable. It is demonstrated that this technique is able to provide good outcomes for all victims of accidental hypothermia.

Real-time instrument detection in minimally invasive surgery using radiofrequency identification technology.

BACKGROUND: A key part of surgical workflow recording is recognition of the instrument in use. We present a radiofrequency identification (RFID)-based approach for real-time tracking of laparoscopic instruments. METHODS: The system consists of RFID-tagged instruments and an antenna unit positioned on the Mayo stand. For reliability analysis, RFID tracking data were compared with the assessment of the perioperative video data of instrument changes (the reference standard for instrument application detection) in 10 laparoscopic cholecystectomies. When the tagged instrument was on the Mayo stand, it was referred to as "not in use." Once it was handed to the surgeon, it was considered to be "in use." Temporal miscounts (incorrect number of instruments "in use") were analyzed. The surgeons and scrub nurses completed a questionnaire after each operation for individual system evaluation. RESULTS: A total of 110 distinct instrument applications ("in use" versus "not in use") were eligible for analysis. No RFID tag failure occurred. The RFID detection rates were consistent with the period of effective instrument application. The delay in instrument detection was 4.2 ± 1.7 s. The highest percentage of temporal miscounts occurred during phases with continuous application of coagulation current. Surgeons generally rated the system better than the scrub nurses (P = 0.54). CONCLUSIONS: The feasibility of RFID-based real-time instrument detection was successfully proved in our study, with reliable detection results during laparoscopic cholecystectomy. Thus, RFID technology has the potential to be a valuable additional tool for surgical workflow recognition that could enable a situation dependent assistance of the surgeon in the future.

A randomized controlled trial evaluating endoscopic and laparoscopic training in skills transfer for novices performing a simulated NOTES task.

BACKGROUND: The NOSCAR white paper lists training as an important step to the safe clinical application of natural orifice translumenal endoscopic surgery (NOTES). The aim of this randomized controlled trial was to evaluate whether training novices in either a laparoscopic or endoscopic simulator curriculum would affect performance in a NOTES simulator task. METHODS: A total of 30 third-year medical undergraduates were recruited. They were randomized to 3 groups: no training (control; n = 10), endoscopy training on a validated colonoscopy simulator protocol (n = 10), and training on a validated laparoscopy simulator curriculum (n = 10). All participants subsequently completed a simulated NOTES task, consisting of 7 steps, on the ELITE (endoscopic-laparoscopic interdisciplinary training entity) model. Performance was assessed as time taken to complete individual steps, overall task time, and number of errors. RESULTS: The endoscopy group was significantly faster than the control group at accessing the peritoneal cavity through the gastric incision (median 27 vs 78 s; P = .015), applying diathermy to the base of the appendix (median 103.5 vs 173 s; P = .014), and navigating to the gallbladder (median 76 vs 169.5 s; P = .049). Endoscopy participants completed the full NOTES procedure in a shorter time than the laparoscopy group (median 863 vs 2074 s; P < .001). CONCLUSION: This study highlights the importance of endoscopic training for a simulated NOTES task that involves both navigation and resection with operative maneuvers. Although laparoscopic training confers some benefit for operative steps such as applying diathermy to the gallbladder fossa, this was not as beneficial as training in endoscopy.

Toward increased autonomy in the surgical OR: needs, requests, and expectations.

BACKGROUND: The current trend in surgery toward further trauma reduction inevitably leads to increased technological complexity. It must be assumed that this situation will not stay under the sole control of surgeons; mechanical systems will assist them. Certain segments of the work flow will likely have to be taken over by a machine in an automatized or autonomous mode. METHODS: In addition to the analysis of our own surgical practice, a literature search of the Medline database was performed to identify important aspects, methods, and technologies for increased operating room (OR) autonomy. RESULTS: Robotic surgical systems can help to increase OR autonomy by camera control, application of intelligent instruments, and even accomplishment of automated surgical procedures. However, the important step from simple task execution to autonomous decision making is difficult to realize. Another important aspect is the adaption of the general technical OR environment. This includes adaptive OR setting and context-adaptive interfaces, automated tool arrangement, and optimal visualization. Finally, integration of peri- and intraoperative data consisting of electronic patient record, OR documentation and logistics, medical imaging, and patient surveillance data could increase autonomy. CONCLUSIONS: To gain autonomy in the OR, a variety of assistance systems and methodologies need to be incorporated that endorse the surgeon autonomously as a first step toward the vision of cognitive surgery. Thus, we require establishment of model-based surgery and integration of procedural tasks. Structured knowledge is therefore indispensable.

Educational and training aspects of new surgical techniques: experience with the endoscopic­laparoscopic interdisciplinary training entity (ELITE) model in training for a natural orifice translumenal endoscopic surgery (NOTES) approach to appendectomy.

BACKGROUND: Natural orifice translumenal endoscopic surgery (NOTES) is a new surgical concept that requires training before it is introduced into clinical practice. The endoscopic­laparoscopic interdisciplinary training entity (ELITE) is a training model for NOTES interventions. The latest research has concentrated on new materials for organs with realistic optical and haptic characteristics and the possibility of high-frequency dissection. This study aimed to assess both the ELITE model in a surgical training course and the construct validity of a newly developed NOTES appendectomy scenario. METHODS: The 70 attendees of the 2010 Practical Course for Visceral Surgery (Warnemuende, Germany) took part in the study and performed a NOTES appendectomy via a transsigmoidal access. The primary end point was the total time required for the appendectomy, including retrieval of the appendix. Subjective evaluation of the model was performed using a questionnaire. Subgroups were analyzed according to laparoscopic and endoscopic experience. RESULTS: The participants with endoscopic or laparoscopic experience completed the task significantly faster than the inexperienced participants (p = 0.009 and 0.019, respectively). Endoscopic experience was the strongest influencing factor, whereas laparoscopic experience had limited impact on the participants with previous endoscopic experience. As shown by the findings, 87.3% of the participants stated that the ELITE model was suitable for the NOTES training scenario, and 88.7% found the newly developed model anatomically realistic. CONCLUSIONS: This study was able to establish face and construct validity for the ELITE model with a large group of surgeons. The ELITE model seems to be well suited for the training of NOTES as a new surgical technique in an established gastrointestinal surgery skills course.

Real-time monitoring for detection of retained surgical sponges and team motion in the surgical operation room using radio-frequency-identification (RFID) technology: a preclinical evaluation.

BACKGROUND: Technical progress in the surgical operating room (OR) increases constantly, facilitating the development of intelligent OR systems functioning as "safety backup" in the background of surgery. Precondition is comprehensive data retrieval to identify imminent risky situations and inaugurate adequate security mechanisms. Radio-frequency-identification (RFID) technology may have the potential to meet these demands. METHODS: We set up a pilot study investigating feasibility and appliance reliability of a stationary RFID system for real-time surgical sponge monitoring (passive tagged sponges, position monitoring: mayo-stand/abdominal situs/waste bucket) and OR team tracking (active transponders, position monitoring: right/left side of OR table). RESULTS: In vitro: 20/20 sponges (100%) were detected on the mayo-stand and within the OR-phantom, however, real-time detection accuracy declined to 7/20 (33%) when the tags were moved simultaneously. All retained sponges were detected correctly. In vivo (animal): 7-10/10 sterilized sponges (70%-100%) were detected correctly within the abdominal cavity. OR-team: detection accuracy within the OR (surveillance antenna) and on both sides of the OR table (sector antenna) was 100%. Mean detection time for position change (left to right side and contrariwise) was 30-60 s. No transponder failure was noted. CONCLUSION: This is the first combined RFID system that has been developed for stationary use in the surgical OR. Preclinical evaluation revealed a reliable sponge tracking and correct detection of retained textiles (passive RFID) but also demonstrated feasibility of comprehensive data acquisition of team motion (active RFID). However, detection accuracy needs to be further improved before implementation into the surgical OR.

Toll-like receptor 2-mediated innate immune response in human nonparenchymal liver cells toward adeno-associated viral vectors.

UNLABELLED: Adeno-associated viral vectors (rAAV) are frequently used in gene therapy trials. Although rAAV vectors are of low immunogenicity, humoral as well as T cell responses may be induced. While the former limits vector reapplication, the expansion of cytotoxic T cells correlates with liver inflammation and loss of transduced hepatocytes. Because adaptive immune responses are a consequence of recognition by the innate immune system, we aimed to characterize cell autonomous immune responses elicited by rAAV in primary human hepatocytes and nonparenchymal liver cells. Surprisingly, Kupffer cells, but also liver sinusoidal endothelial cells, mounted responses to rAAV, whereas neither rAAV2 nor rAAV8 were recognized by hepatocytes. Viral capsids were sensed at the cell surface as pathogen-associated molecular patterns by Toll-like receptor 2. In contrast to the Toll-like receptor 9-mediated recognition observed in plasmacytoid dendritic cells, immune recognition of rAAV in primary human liver cells did not induce a type I interferon response, but up-regulated inflammatory cytokines through activation of nuclear factor κB. CONCLUSION: Using primary human liver cells, we identified a novel mechanism of rAAV recognition in the liver, demonstrating that alternative means of sensing rAAV particles have evolved. Minimizing this recognition will be key to improving rAAV-mediated gene transfer and reducing side effects in clinical trials due to immune responses against rAAV.

Palliative resections versus palliative bypass procedures in pancreatic cancer--a systematic review.

BACKGROUND: Although resection is the only treatment option that offers a chance for prolonged survival in pancreatic cancer, R2 resections are controversial and not a generally accepted approach. METHODS: A systematic review and meta-analysis of studies of patients with pancreatic cancer was performed to analyze R2 resections in comparison with palliative surgical bypass procedures. Trials were identified by searching MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials from 1966 to February 2011. RESULTS: Four cohort studies were identified comparing 138 patients with R2 resections with 261 patients undergoing surgical bypass procedures. Morbidity and mortality were increased in the R2 resection group, with pooled risk ratios of 1.75 (95% confidence interval [CI], 1.35-2.26; P < .0001) and 2.98 (95% CI, 1.31-6.75; P = .009), respectively. R2 resections were associated with longer operating times (mean difference, 164 minutes; 95% CI, 127-201 minutes; P < .00001) and hospital stays (mean difference, 5 days; 95% CI, 1-9 days; P = .02). Pooled median survival times were 8.2 months for R2 resection and 6.7 months for palliative bypass procedures. CONCLUSIONS: Planned palliative R2 resections are not justified in patients with pancreatic cancer.

Telomerase gene mutations are associated with cirrhosis formation.

UNLABELLED: Telomere shortening impairs liver regeneration in mice and is associated with cirrhosis formation in humans with chronic liver disease. In humans, telomerase mutations have been associated with familial diseases leading to bone marrow failure or lung fibrosis. It is currently unknown whether telomerase mutations associate with cirrhosis induced by chronic liver disease. The telomerase RNA component (TERC) and the telomerase reverse transcriptase (TERT) were sequenced in 1,121 individuals (521 patients with cirrhosis induced by chronic liver disease and 600 noncirrhosis controls). Telomere length was analyzed in patients carrying telomerase gene mutations. Functional defects of telomerase gene mutations were investigated in primary human fibroblasts and patient-derived lymphocytes. An increased incidence of telomerase mutations was detected in cirrhosis patients (allele frequency 0.017) compared to noncirrhosis controls (0.003, P value 0.0007; relative risk [RR] 1.859; 95% confidence interval [CI] 1.552-2.227). Cirrhosis patients with TERT mutations showed shortened telomeres in white blood cells compared to control patients. Cirrhosis-associated telomerase mutations led to reduced telomerase activity and defects in maintaining telomere length and the replicative potential of primary cells in culture. CONCLUSION: This study provides the first experimental evidence that telomerase gene mutations are present in patients developing cirrhosis as a consequence of chronic liver disease. These data support the concept that telomere shortening can represent a causal factor impairing liver regeneration and accelerating cirrhosis formation in response to chronic liver disease.

Transgastric or trans-sigmoidal? The impact of the choice of access on task performance in target natural orifice translumenal endoscopic surgery procedures.

INTRODUCTION: The effect of the choice of access upon endoscope control during a navigational task is explored within a simulator model. MATERIALS AND METHODS: The study was conducted within the endoscopic-laparoscopic interdisciplinary training entity (ELITE) model (Minimally Invasive Therapy and Intervention Research Group [MITI], Technische Universität, Germany)--a validated natural orifice translumenal endoscopic surgery (NOTES) simulator. Seventeen subjects, 15 with no endoscopic experience, navigated the endoscope from predefined trans-sigmoidal and transgastric access points to the appendix and the gallbladder. A previously defined and validated quantitative analysis of endoscope control, in addition to time taken to complete the task, was used to evaluate overall performance. The quantitative analysis extrapolated the movements of the subject's wrist in control of the endoscope and rated the movements using a scoring system of 0-3 based upon the smoothness of the movements recorded. RESULTS: Although no significant difference in terms of performance time was demonstrated between the two approaches to the appendix (36.6 ± 14.7 seconds TG and 29.8 ± 16 seconds TS) (P = .214), when the endoscope control score was compared, a significant difference was confirmed (3 TG and 7 TS) (P < .001). With regard to the approach to the gallbladder, a significant difference in terms of both the performance time (19.8 seconds TG and 35.6 seconds TS) (P < .001) and the quality of endoscope control (7 TG and 5 TS) (P = .001) was demonstrated. CONCLUSION: The choice of access route impacts directly on the ease with which the endoscopist navigates to the target. Within this study, the trans-sigmoidal appears the most appropriate to access the appendix and the transgastric for the gallbladder.

Massive intra-abdominal bleeding caused by nontraumatic rupture of a vein in the colorenal ligament: report of a case.

We report a case of acute abdomen caused by nontraumatic intra-abdominal bleeding in a 38-year-old man. Emergency laparotomy revealed the source of bleeding as a vein in the right colorenal ligament. The rupture of this vein may have been attributable to shear stress after severe vomiting on the day before admission. Although the patient had a coagulation disorder secondary to early-stage liver cirrhosis, there were no signs of portal hypertension intraoperatively. This report describes an unusual cause of acute hemoperitoneum, highlighting the importance of including this life-threatening disorder in the differential diagnosis of acute abdomen of unknown origin. Its outcome is dependent on early diagnosis and prompt emergency intervention.

New technologies for information retrieval to achieve situational awareness and higher patient safety in the surgical operating room: the MRI institutional approach and review of the literature.

BACKGROUND: Technical progress in the operating room (OR) increases constantly, but advanced techniques for error prevention are lacking. It has been the vision to create intelligent OR systems ("autopilot") that not only collect intraoperative data but also interpret whether the course of the operation is normal or deviating from the schedule ("situation awareness"), to recommend the adequate next steps of the intervention, and to identify imminent risky situations. METHODS: Recently introduced technologies in health care for real-time data acquisition (bar code, radiofrequency identification [RFID], voice and emotion recognition) may have the potential to meet these demands. This report aims to identify, based on the authors' institutional experience and a review of the literature (MEDLINE search 2000-2010), which technologies are currently most promising for providing the required data and to describe their fields of application and potential limitations. RESULTS: Retrieval of information on the functional state of the peripheral devices in the OR is technically feasible by continuous sensor-based data acquisition and online analysis. Using bar code technologies, automatic instrument identification seems conceivable, with information given about the actual part of the procedure and indication of any change in the routine workflow. The dynamics of human activities also comprise key information. A promising technology for continuous personnel tracking is data acquisition with RFID. Emotional data capture and analysis in the OR are difficult. Although technically feasible, nonverbal emotion recognition is difficult to assess. In contrast, emotion recognition by speech seems to be a promising technology for further workflow prediction. CONCLUSION: The presented technologies are a first step to achieving an increased situational awareness in the OR. However, workflow definition in surgery is feasible only if the procedure is standardized, the peculiarities of the individual patient are taken into account, the level of the surgeon's expertise is regarded, and a comprehensive data capture can be obtained.

Healing occurs in most patients that receive endoscopic stents for anastomotic leakage; dislocation remains a problem.

BACKGROUND & AIMS: There is controversy about the best way to treat esophageal anastomotic leakage. We evaluated the effects of treatment with self-expanding metal stents in patients with esophageal anastomotic leakage after esophagectomy or gastrectomy for cancer. METHODS: We investigated outcomes and procedure-related complications of 115 patients who received endoscopic stents for anastomotic leakage after esophagectomy or gastrectomy at a university hospital from 2004 to 2009. We also performed a systematic literature review on stent therapy and compared outcomes with that of other treatment regimens for esophageal anastomotic leakage. RESULTS: Among the 115 patients who received stents, the in-hospital mortality rate was 9% and complete anastomotic healing was achieved in 70% (95% confidence interval [CI], 64%-76%). Stent dislocation occurred in 53% of the patients (95% CI, 43%-62%), in all patients with esophagocolonostomy, in 61% with esophagojejunostomy, and in 49% with esophagogastrostomy. Three percent of patients (95% CI, 1%-5%) needed laparotomy to remove dislocated stents. Elective endoscopic stent removal was performed in 80% of the patients after a median of 54 days (range 17-427 d); 12% of these patients developed symptomatic anastomotic strictures after stent removal. CONCLUSIONS: Anastomoses completely heal in 70% of patients that receive endoscopic stents for anastomotic leakage after esophagectomy or gastrectomy. Stent therapy should be used in the management of patients with adequately perfused esophageal anastomotic leakage. However, stent dislocation remains a common problem after surgery.

Palliative interventional and surgical therapy for unresectable pancreatic cancer.

Palliative treatment concepts are considered in patients with non-curatively resectable and/or metastasized pancreatic cancer. However, patients without metastases, but presented with marginally resectable or locally non-resectable tumors should not be treated by a palliative therapeutic approach. These patients should be enrolled in neoadjuvant radiochemotherapy trials because a potentially curative resection can be achieved in approximately one-third of them after finishing treatment and restaging. Within the scope of best possible palliative care, resection of the primary cancer together with excision of metastases represents a therapeutic option to be contemplated in selected cases. Comprehensive palliative therapy is based on treatment of bile duct or duodenal obstruction for certain locally unresectable or metastasized advanced pancreatic cancer. However, endoscopic or percutaneous stenting procedures and surgical bypass provide safe and highly effective therapeutic alternatives. In case of operative drainage of the biliary tract (biliodigestive anastomosis), the prophylactic creation of a gastro-intestinal bypass (double bypass) is recommended. The decision to perform a surgical versus an endoscopic procedure for palliation depends to a great extent on the tumor stage and the estimated prognosis, and should be determined by an interdisciplinary team for each patient individually.

Reduced expression of the membrane skeleton protein beta1-spectrin (SPTBN1) is associated with worsened prognosis in pancreatic cancer.

Spectrins are members of the superfamily of F-actin cross linking proteins that are important as scaffolding proteins for protein sorting, cell adhesion, and migration. In addition, spectrins have been implicated in TGF-beta signaling. The aim of the present study was to analyze the expression and localization of beta1-spectrin (SPTBN1) in pancreatic tissues. mRNA levels of SPTBN1 in cultured pancreatic cancer cell lines, as well as in normal pancreatic tissues (n=18), chronic pancreatitis (n=48) and pancreatic cancer tissues (n=66) were analyzed by real time quantitative RT-PCR. Localization of SPTBN1 in pancreatic tissues was determined by immunohistochemistry. SPTBN1 staining was assessed semi-quantitatively in 55 cancer tissues and survival analysis was carried out using the Kaplan-Meier method. Median SPTBN1 mRNA levels were 6.0-fold higher in pancreatic cancer tissues compared to the normal pancreas (p<0.0001) and 2.2-fold higher compared to chronic pancreatitis tissues (p=0.0002). In the normal pancreas, SPTBN1 was present in the cytoplasm of normal ductal cells and occasionally in pancreatic acinar and centroacinar cells. In pancreatic cancer tissues, SPTBN1 was present in the cytoplasm of pancreatic cancer cells. Low SPTBN1 protein expression indicated a tendency for worsened prognosis with a median survival of 14.0 months, versus 23.8 months for patients whose tumors expressed moderate/high levels of SPTBN1. In conclusion, reduced SPTBN1 expression correlated with shorter survival of pancreatic cancer patients, suggesting a tumor suppressor function of this gene, as has already been shown for other malignancies of the gastrointestinal tract.

ELITE--the ex vivo training unit for NOTES: development and validation.

Skill training is an essential part of surgical education. Every physician has to get familiar with the various operation techniques and needs to handle the different instruments. However, mechanical and computer-based VR-simulators offer only one specific procedure, either laparoscopic or endoscopic. We designed the universal training system ELITE (endoscopic-laparoscopic interdisciplinary training entity) which is a new full synthetic ex vivo surgical training model for laparoscopic surgery, combined endoluminal/endocavitary procedures ("hybrid surgery") and NOTES. The aim of the current investigation was to integrate respiration and electro dissection into the model, and the evaluation of both innovations. The ELITE is a full-size replica of a human female torso including a gas-tight abdominal wall and offering various accesses to the abdomen. A complete organ package including liver, gallbladder, spleen, gastrointestinal tract, including the mesentery and omentum is available for this system. Cholecystectomy and appendectomy can be simulated realistically with this new training system. For more realistic conditions during operations breathing-induced organ motion could be integrated into this system. Two latex balloons were inserted into the system to imitate the function of the diaphragm. They are inflated and deflated according to the respiration cycle and move the artificial organs in a natural way. Physicians, including endoscopic/laparoscopic novices and experts, were asked to train different NOTES procedures on the model. Performance of their training and subjective appraisal of the model itself were evaluated. The opportunity of electrodissection of the gallbladder and appendix and simulation of breath excursion of the diaphragm could successfully be implemented into the training system. One recently published study showed that ELITE is a suitable tool to train different surgical procedures. All subjects (novices and endoscopic/laparoscopic experts) showed a significant learning curve during the assessment. Experts could be reliably differentiated from novices. The actual evaluation of the model showed that 97% of the subjects considered the ELITE as a useful simulator for NOTES. ELITE was validated to be a suitable tool to train different NOTES procedures. As a step by step training of NOTES is highly recommended, this training system offers the opportunity by degrees that animal experiments can be replaced, especially, for learning of basic techniques and thus costs can be significantly reduced.

Natural orifice transluminal endoscopic surgery in pancreatic diseases.

Natural orifice transluminal endoscopic surgery (NOTES) is a surgical technique that has received considerable interest in recent years. Although minimal access surgery has increasingly replaced traditional open abdominal surgical approaches for a wide spectrum of indications, in pancreatic diseases its widespread use is limited to few indications because of the challenging and demanding nature of major pancreatic operations. Nonetheless, there have been attempts in animal models as well as in the clinical setting to perform diagnostic and resectional NOTES for pancreatic diseases. Here, we review and comment upon the available data regarding currently analyzed and performed pancreatic NOTES procedures. Potential indications for NOTES include peritoneoscopy, cyst drainage, and necrosectomy, palliative procedures such as gastroenterostomy, as well as resections such as distal pancreatectomy or enucleation. These procedures have already been shown to be technically feasible in several studies in animal models and a few clinical trials. In conclusion, NOTES is a rapidly developing concept/technique that could potentially become an integral part of the armamentarium dealing with surgical approaches to pancreatic diseases.

Preoperative/neoadjuvant therapy in pancreatic cancer: a systematic review and meta-analysis of response and resection percentages.

BACKGROUND: Pancreatic cancer has an extremely poor prognosis and prolonged survival is achieved only by resection with macroscopic tumor clearance. There is a strong rationale for a neoadjuvant approach, since a relevant percentage of pancreatic cancer patients present with non-metastatic but locally advanced disease and microscopic incomplete resections are common. The objective of the present analysis was to systematically review studies concerning the effects of neoadjuvant therapy on tumor response, toxicity, resection, and survival percentages in pancreatic cancer. METHODS AND FINDINGS: Trials were identified by searching MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials from 1966 to December 2009 as well as through reference lists of articles and proceedings of major meetings. Retrospective and prospective studies analyzing neoadjuvant radiochemotherapy, radiotherapy, or chemotherapy of pancreatic cancer patients, followed by re-staging, and surgical exploration/resection were included. Two reviewers independently extracted data and assessed study quality. Pooled relative risks and 95% confidence intervals were calculated using random-effects models. Primary outcome measures were proportions of tumor response categories and percentages of exploration and resection. A total of 111 studies (n = 4,394) including 56 phase I-II trials were analyzed. A median of 31 (interquartile range [IQR] 19-46) patients per study were included. Studies were subdivided into surveys considering initially resectable tumors (group 1) and initially non-resectable (borderline resectable/unresectable) tumors (group 2). Neoadjuvant chemotherapy was given in 96.4% of the studies with the main agents gemcitabine, 5-FU (and oral analogues), mitomycin C, and platinum compounds. Neoadjuvant radiotherapy was applied in 93.7% of the studies with doses ranging from 24 to 63 Gy. Averaged complete/partial response probabilities were 3.6% (95% CI 2%-5.5%)/30.6% (95% CI 20.7%-41.4%) and 4.8% (95% CI 3.5%-6.4%)/30.2% (95% CI 24.5%-36.3%) for groups 1 and 2, respectively; whereas progressive disease fraction was estimated to 20.9% (95% CI 16.9%-25.3%) and 20.8% (95% CI 14.5%-27.8%). In group 1, resectability was estimated to 73.6% (95% CI 65.9%-80.6%) compared to 33.2% (95% CI 25.8%-41.1%) in group 2. Higher resection-associated morbidity and mortality rates were observed in group 2 versus group 1 (26.7%, 95% CI 20.7%-33.3% versus 39.1%, 95% CI 29.5%-49.1%; and 3.9%, 95% CI 2.2%-6% versus 7.1%, 95% CI 5.1%-9.5%). Combination chemotherapies resulted in higher estimated response and resection probabilities for patients with initially non-resectable tumors ("non-resectable tumor patients") compared to monotherapy. Estimated median survival following resection was 23.3 (range 12-54) mo for group 1 and 20.5 (range 9-62) mo for group 2 patients. CONCLUSIONS: In patients with initially resectable tumors ("resectable tumor patients"), resection frequencies and survival after neoadjuvant therapy are similar to those of patients with primarily resected tumors and adjuvant therapy. Approximately one-third of initially staged non-resectable tumor patients would be expected to have resectable tumors following neoadjuvant therapy, with comparable survival as initially resectable tumor patients. Thus, patients with locally non-resectable tumors should be included in neoadjuvant protocols and subsequently re-evaluated for resection.