Primary Open Versus Closed Implantation Strategy for Totally Implantable Venous Access Ports: The Multicentre Randomized Controlled PORTAS-3 Trial (DRKS 00004900).

OBJECTIVES: PORTAS-3 was designed to compare the frequency of pneumothorax or haemothorax in a primary open versus closed strategy for port implantation. BACKGROUND DATA: The implantation strategy for totally implantable venous access ports with the optimal benefit/risk ratio remains unclear. METHODS: PORTAS-3 was a multicentre, randomized, controlled, parallel-group superiority trial. Adult patients with oncological disease scheduled for elective port implantation were randomized to a primary open or closed strategy. Primary endpoint was the rate of pneumothorax or haemothorax. Assuming a difference of 2.5% between the 2 groups, a sample size of 1154 patients was needed to prove superiority of the open group. A logistic regression model after the intention-to-treat principle was applied for analysis of the primary endpoint. RESULTS: Between November 9, 2014 and September 5, 2016, 1205 patients were randomized. Of these, 1159 (open n = 583; closed n = 576) were finally analyzed. The rate of pneumothorax or haemothorax was significantly reduced with the open strategy [odds ratio 0.27, 95% confidence interval (CI) 0.09-0.88; P = 0.029]. Operation time was shorter for the closed strategy. Primary success rates, tolerability, morbidity, dose rate of radiation, and 30-day mortality did not differ significantly between the groups. CONCLUSION: A primary open strategy by cut-down of the cephalic vein, if necessary enhanced by a modified Seldinger technique, reduces the frequency of pneumothorax or haemothorax after central venous port implantation significantly compared with a closed strategy by primary puncture of the subclavian vein without routine sonographic guidance. Therefore, open surgical cut-down should be the reference standard for port implantation in comparable cohorts. TRIAL REGISTRATION: German Clinical Trials Register DRKS 00004900.

Computer tomographic analysis of organ motion caused by respiration and intraoperative pneumoperitoneum in a porcine model for navigated minimally invasive esophagectomy.

BACKGROUND: Navigation systems have the potential to facilitate intraoperative orientation and recognition of anatomical structures. Intraoperative accuracy of navigation in thoracoabdominal surgery depends on soft tissue deformation. We evaluated esophageal motion caused by respiration and pneumoperitoneum in a porcine model for minimally invasive esophagectomy. METHODS: In ten pigs (20-34 kg) under general anesthesia, gastroscopic hemoclips were applied to the cervical (CE), high (T1), middle (T2), and lower thoracic (T3) level, and to the gastroesophageal junction (GEJ) of the esophagus. Furthermore, skin markers were applied. Three-dimensional (3D) and four-dimensional (4D) computed tomography (CT) scans were acquired before and after creation of pneumoperitoneum. Marker positions and lung volumes were analyzed with open source image segmentation software. RESULTS: Respiratory motion of the esophagus was higher at T3 (7.0 ± 3.3 mm, mean ± SD) and GEJ (6.9 ± 2.8 mm) than on T2 (4.5 ± 1.8 mm), T1 (3.1 ± 1.8 mm), and CE (1.3 ± 1.1 mm). There was significant motion correlation in between the esophageal levels. T1 motion correlated with all other esophagus levels (r = 0.51, p = 0.003). Esophageal motion correlated with ventilation volume (419 ± 148 ml) on T1 (r = 0.29), T2 (r = 0.44), T3 (r = 0.54), and GEJ (r = 0.58) but not on CE (r = - 0.04). Motion correlation of the esophagus with skin markers was moderate to high for T1, T2, T3, GEJ, but not evident for CE. Pneumoperitoneum led to considerable displacement of the esophagus (8.2 ± 3.4 mm) and had a level-specific influence on respiratory motion. CONCLUSIONS: The position and motion of the esophagus was considerably influenced by respiration and creation of pneumoperitoneum. Esophageal motion correlated with respiration and skin motion. Possible compensation mechanisms for soft tissue deformation were successfully identified. The porcine model is similar to humans for respiratory esophageal motion and can thus help to develop navigation systems with compensation for soft tissue deformation.

Glycine Protects the Liver from Reperfusion Injury following Pneumoperitoneum.

BACKGROUND: Experimental pneumoperitoneum induces ischemia/reperfusion injury (IRI) in the liver, most likely via Kupffer cell (KC)-dependent mechanisms. Glycine has been shown to ameliorate IRI in various animal models. Thus, this study was performed to assess the effects of glycine on the liver after pneumoperitoneum. MATERIALS AND METHODS: Sprague-Dawley rats (220-250 g in weight) underwent CO2 pneumoperitoneum (12 mm Hg) for 90 min. Some rats received i.v. glycine (1.5 mL, 300 mM) 10 min before pneumoperitoneum. Controls were given the same volume of Ringer's solution. Transaminases, hepatic microcirculation, and phagocytosis of latex beads indexing both liver injury and KC activation were examined following pneumoperitoneum. Analysis of variance (ANOVA), plus a subsequent t test or χ2 test (or Fisher's exact test) were carried out as appropriate. Results are presented as mean ± SEM. RESULTS: Glycine significantly decreased lactate dehydrogenase at 1 h and both aspartate aminotransferase and alanine aminotransferase at 2 h after pneumoperitoneum from 477 ± 43, 154 ± 17, and 60 ± 6 U/L in controls to 348 ± 25, 101 ± 11, and 34 ± 3 U/L, respectively (p < 0.05). In parallel, glycine significantly decreased both the rate of permanent adherence of leukocytes to the endothelium by up to 35% and the rate of phagocytosis by > 50% compared to the control group. CONCLUSION: Glycine decreased IRI after pneumoperitoneum, most likely via KC-dependent mechanisms.

Laparoscopic Mesh-augmented Hiatoplasty With Cardiophrenicopexy Versus Laparoscopic Nissen Fundoplication for the Treatment of Gastroesophageal Reflux Disease: A Double-center Randomized Controlled Trial.

OBJECTIVE: Laparoscopic mesh-augmented hiatoplasty with cardiophrenicopexy (LMAH-C) might represent an alternative treatment of gastroesophageal reflux disease (GERD) and may provide durable reflux control without fundoplication. The expected benefit is the prevention of fundoplication-related side effects. Aim of the present trial was to compare LMAH-C with laparoscopic Nissen fundoplication (LNF) in patients with GERD. METHODS: In a double-center randomized controlled trial (RCT) patients with proven GERD were eligible and assigned by central randomization to either LMAH-C (n = 46) or LNF (n = 44). The indigestion subscore of the Gastrointestinal Symptom Rating Scale questionnaire (GSRS) indicating gas-related symptoms as possible side effects of LNF was the primary endpoint. Secondary endpoints comprised pH testing and endoscopy and other symptoms measured by the GSRS, dysphagia, and the Gastrointestinal Quality of Life Index. The follow-up period was 36 months. RESULTS: Indigestion subscore (LMAH-C 2.9 ±â€Š1.5 vs LNF 3.7 ±â€Š1.6; P = 0.031) but not dysphagia (2.8 ±â€Š1.9 vs 2.3 ±â€Š1.7; P = 0.302) and quality of life (106.9 ±â€Š25.5 vs 105.8 ±â€Š24.9; P = 0.838) differed between the groups at 36 months postoperatively. Although the reflux subscore improved in both groups, it was worse in LMAH-C patients (2.5 ±â€Š1.6 vs 1.6 ±â€Š1.0; P = 0.004) corresponding to a treatment failure of 77.3% in LMAH-C patients and of 34.1% in LNF patients (P < 0.001). CONCLUSIONS: LNF is more effective in the treatment of GERD than LMAH-C. Procedure-related side effects seem to exist but do not affect the quality of life. Laparoscopic fundoplication therefore remains the standard surgical treatment for GERD.

The TICAP-Study (titanium clips for appendicular stump closure): A prospective multicentre observational study on appendicular stump closure with an innovative titanium clip.

BACKGROUND: To evaluate the effectiveness and safety of the DS Titanium Ligation Clip for appendicular stump closure in laparoscopic appendectomy. METHODS: Overall, 502 patients undergoing laparoscopic appendectomy were recruited for this observational multicentre study in nine study centres between October 2011 and July 2013. The clip was finally applied in 390 patients. Primary outcome variables were feasibility of the clip, intra-abdominal surgical site (abscesses, stump leakages) and superficial wound infections. Patients were followed 30 days after surgery. RESULTS: The clip was applicable in nearly 80 % of patients. Reasons for not applying the clip were mainly an inflamed caecum or a too large diameter of the appendix base. Superficial wound infections were found in nine (2.31 %), intra-abdominal abscesses in five (1.28 %), appendicular stump leak in one (0.26 %), and other adverse events in 22 (5.64 %) patients. In total, 12 (3.08 %) patients were re-admitted to hospital for treatment. Seven re-admissions were surgery-related; ten (2.56 %) patients had to be re-operated. One patient died during the course of the study due to persisting peritonitis (mortality 0.26 %). CONCLUSIONS: The results suggest that the DS Titanium Ligation Clip is a safe and effective option in securing the appendicular stump in laparoscopic appendectomy. The complication rates found with the use of the DS-Clip are comparable to the rates in the literature when other methods are used. TRIAL REGISTRATION: NCT01734837 .

Laparoscopic mesh-augmented hiatoplasty without fundoplication as a method to treat large hiatal hernias.

PURPOSE: Laparoscopic hiatal hernia repair with additional fundoplication is a commonly recommended standard surgical treatment for symptomatic large hiatal hernias with paraesophageal involvement (PEH). However, due to the risk of persistent side effects, this method remains controversial. Laparoscopic mesh-augmented hiatoplasty without fundoplication (LMAH), which combines hiatal repair and mesh reinforcement, might therefore be an alternative. METHODS: In this retrospective study of 55 (25 male, 30 female) consecutive PEH patients, the perioperative course and symptomatic outcomes were analyzed after a mean follow-up of 72 months. RESULTS: The mean DeMeester symptom score decreased from 5.1 to 1.8 (P < 0.001) and the gas bloating value decreased from 1.2 to 0.5 (P = 0.001). The dysphagia value was 0.7 before surgery and 0.6 (P = 0.379) after surgery. The majority of the patients were able to belch and vomit (96 and 92 %, respectively). Acid-suppressive therapy on a regular basis was discontinued in 68 % of patients. In 4 % of patients, reoperation was necessary due to recurrent or persistent reflux. A mesh-related stenosis that required endoscopic dilatation occurred in 2 % of patients. CONCLUSIONS: LMAH is feasible, safe and provides an anti-reflux effect, even without fundoplication. As operation-related side effects seem to be rare, LMAH is a potential treatment option for large hiatal hernias with paraesophageal involvement.

Acute cholecystitis: early versus delayed cholecystectomy, a multicenter randomized trial (ACDC study, NCT00447304).

OBJECTIVE: Acute cholecystitis is a common disease, and laparoscopic surgery is the standard of care. BACKGROUND: Optimal timing of surgery for acute cholecystitis remains controversial: either early surgery shortly after hospital admission or delayed elective surgery after a conservative treatment with antibiotics. METHODS: The ACDC ("Acute Cholecystitis-early laparoscopic surgery versus antibiotic therapy and Delayed elective Cholecystectomy") study is a randomized, prospective, open-label, parallel group trial. Patients were randomly assigned to receive immediate surgery within 24 hours of hospital admission (group ILC) or initial antibiotic treatment, followed by delayed laparoscopic cholecystectomy at days 7 to 45 (group DLC). For infection, all patients were treated with moxifloxacin for at least 48 hours. Primary endpoint was occurrence of predefined relevant morbidity within 75 days. Secondary endpoints were as follows: (1) 75-day morbidity using a scoring system; (2) conversion rate; (3) change of antibiotic therapy; (4) mortality; (5) costs; and (6) length of hospital stay. RESULTS: Morbidity rate was significantly lower in group ILC (304 patients) than in group DLC (314 patients): 11.8% versus 34.4%. Conversion rate to open surgery and mortality did not differ significantly between groups. Mean length of hospital stay (5.4 days vs 10.0 days; P < 0.001) and total hospital costs (€2919 vs €4262; P < 0.001) were significantly lower in group ILC. CONCLUSIONS: In this large, randomized trial, laparoscopic cholecystectomy within 24 hours of hospital admission was shown to be superior to the conservative approach concerning morbidity and costs. Therefore, we believe that immediate laparoscopic cholecystectomy should become therapy of choice for acute cholecystitis in operable patients. (NCT00447304).

Navigation system for minimally invasive esophagectomy: experimental study in a porcine model.

BACKGROUND: Navigation systems potentially facilitate minimally invasive esophagectomy and improve patient outcome by improving intraoperative orientation, position estimation of instruments, and identification of lymph nodes and resection margins. The authors' self-developed navigation system is highly accurate in static environments. This study aimed to test the overall accuracy of the navigation system in a realistic operating room scenario and to identify the different sources of error altering accuracy. METHODS: To simulate a realistic environment, a porcine model (n = 5) was used with endoscopic clips in the esophagus as navigation targets. Computed tomography imaging was followed by image segmentation and target definition with the medical imaging interaction toolkit software. Optical tracking was used for registration and localization of animals and navigation instruments. Intraoperatively, the instrument was displayed relative to segmented organs in real time. The target registration error (TRE) of the navigation system was defined as the distance between the target and the navigation instrument tip. The TRE was measured on skin targets with the animal in the 0° supine and 25° anti-Trendelenburg position and on the esophagus during laparoscopic transhiatal preparation. RESULTS: On skin targets, the TRE was significantly higher in the 25° position, at 14.6 ± 2.7 mm, compared with the 0° position, at 3.2 ± 1.3 mm. The TRE on the esophagus was 11.2 ± 2.4 mm. The main source of error was soft tissue deformation caused by intraoperative positioning, pneumoperitoneum, surgical manipulation, and tissue dissection. CONCLUSION: The navigation system obtained acceptable accuracy with a minimally invasive transhiatal approach to the esophagus in a realistic experimental model. Thus the system has the potential to improve intraoperative orientation, identification of lymph nodes and adequate resection margins, and visualization of risk structures. Compensation methods for soft tissue deformation may lead to an even more accurate navigation system in the future.

Virtual reality does not meet expectations in a pilot study on multimodal laparoscopic surgery training.

BACKGROUND: The purpose of the present study was to determine the value of virtual reality (VR) training for a multimodality training program of basic laparoscopic surgery. MATERIALS AND METHODS: Participants in a two-day multimodality training for laparoscopic surgery used box trainers, live animal training, and cadaveric training on the pulsating organ perfusion (POP) trainer in a structured and standardized training program. The participants were divided into two groups. The VR group (n = 13) also practiced with VR training during the program, whereas the control group (n = 14) did not use VR training. The training modalities were assessed using questionnaires with a five-point Likert scale after the program. Concerning VR training, members of the control group assessed their expectations, whereas the VR group assessed the actual experience of using it. Skills performance was evaluated with five standardized test tasks in a live porcine model before (pre-test) and after (post-test) the training program. Laparoscopic skills were measured by task completion time and a general performance score for each task. Baseline tests were compared with laparoscopic experience of all participants for construct validity of the skills test. RESULTS: The expected benefit from VR training of the control group was higher than the experienced benefit of the VR group. Box and POP training received better ratings from the VR group than from the control group for some purposes. Both groups improved their skill parameters significantly from pre-training to post-training tests [score +17 % (P < 0.01), time -29 % (P < 0.01)]. No significant difference was found between the two groups for laparoscopic skills improvement except for the score in the instrument coordination task. Construct validity of the skills test was significant for both time and score. CONCLUSIONS: At its current level of performance, VR training does not meet expectations. No additional benefit was observed from VR training in our multimodality training program.

Comparison of different surgical techniques in distal pancreatectomy: an experimental study in a porcine model.

AIMS: Different surgical transection methods have been used for distal pancreatectomy (DP), but none of them has yet achieved perfect results. This study compares 2 standard transection techniques with the alternative LigaSure technique. METHODS: Forty-eight pigs underwent a DP. Sixteen animals were operated on with a scalpel followed by hand suturing. Sixteen pigs received a DP using an Endo GIA, and the pancreas of 16 pigs was transected with LigaSure. The transection surface of remnant pancreas was observed for liquid collection and abscess on postoperative day 7. RESULTS: Operating time on the day of DP was significantly different, with a shorter operating time in the stapler and LigaSure groups. The morbidity on postoperative day 7 was similar in all groups. CONCLUSION: In the present experimental animal study, LigaSure seems to be fast and safe as well as comparable with the standard transection and closure techniques in DP.

Three-dimensional visualisation improves understanding of surgical liver anatomy.

OBJECTIVES: Three-dimensional (3-D) representation is thought to improve understanding of complex spatial interactions and is being used more frequently in diagnostic and therapeutic procedures. It has been suggested that males benefit more than females from 3-D presentations. There have been few randomised trials to confirm these issues. We carried out a randomised trial, based on the identification of complex surgical liver anatomy, to evaluate whether 3-D presentation has a beneficial impact and if gender differences were evident. METHODS: A computer-based teaching module (TM) was developed to test whether two-dimensional (2-D) computed tomography (CT) images or 3-D presentations result in better understanding of liver anatomy. Following a PowerPoint lecture, students were randomly selected to participate in computer-based testing which used either 2-D images presented as consecutive transversal slices, or one of two 3-D variations. In one of these the vessel tree of portal and hepatic veins was shown in one colour (3-D) and in the other the two vessel systems were coloured differently (3-Dc). Participants were asked to answer 11 medical questions concerning surgical anatomy and four questions on their subjective assessment of the TM. RESULTS: Of the 160 Year 4 and 5 medical students (56.8% female) who participated in this prospective randomised trial, students exposed to 3-D presentation performed significantly better than those exposed to 2-D images (p < 0.001). Comparison of the number of correct answers revealed no significant differences between the 3-D and 3-Dc modalities p > 0.1). Male students gave significantly more correct answers in the 3-D and 3-Dc modalities than female students (p < 0.03). The gender difference observed in both 3-D modalities was not evident in the 2-D group (p = 0.21). CONCLUSIONS: This study showed that 3-D imaging significantly improved the identification of complex surgical liver anatomy. Male students benefited significantly more than female students from 3-D presentations. Use of colour in 3-D presentation did not improve student performance.

The point of conversion in laparoscopic colonic surgery affects the oncologic outcome in an experimental rat model.

BACKGROUND: Approximately 20% of laparoscopic colonic tumor resections result in conversion to open surgery. This result may be related to an increased risk in terms of the oncologic outcome. This study aimed to investigate the oncologic consequences of early and late conversion in laparoscopic colonic surgery. METHODS: For this study, 45 male WAG-Rij rats were randomized into three operation groups of 15 animals each: laparotomy (LT group), laparoscopy followed by early conversion after 20 min (EC group), and laparoscopy followed by late conversion after 40 min (LC group). The total procedure time for the LT and EC groups was 60 min, compared with 80 min for the LC group. Hematogenous metastatic spread was induced in each operation group by tumor cell inoculation of a rat colon adenocarcinoma (CC 531) into the portal vein after 15 min of surgical intervention. A cecal resection was performed after 30 min in the LT and EC groups and after 50 min in the LC group. On day 28 after surgery, hepatic tumor growth was evaluated by measuring the diameter of tumor nodules, the tumor volume, the weight of the liver, and the cancer index. RESULTS: Hepatic tumor volume was significantly increased after LC than after EC (p = 0.01) and LT (p = 0.04). The liver weights in the LC group were significantly higher than in the EC (p = 0.01) and LT (p = 0.01) groups. No significant difference between EC and LT was observed in any parameters surveyed. CONCLUSION: The LC procedure resulted in greater tumor growth than EC and LT. The EC procedure did not lead to significantly more hepatic tumor growth than the same procedure performed using the conventional open technique. From the oncologic point of view, an early decision for conversion must be recommended as soon as any prolonged operating time has to be hypothesized.

Is a circular polypropylene mesh appropriate for application at the esophageal hiatus? Results from an experimental study in a porcine model.

BACKGROUND: Mesh reinforcement in hiatal hernia surgery is debated. Randomized controlled trials have shown that recurrences may be reduced, but there is also the fear of mesh-related complications. Experimental studies on the characteristics of specific mesh types with regard to the risk of such complications are rare. The current study aimed to investigate the properties of a circular heavy-weight polypropylene mesh in terms of stenosis, migration, erosions, and adhesions in a porcine model. METHODS: A 55 x 55-mm heavy-weight polypropylene mesh with a 16.5-mm eccentric hole for the esophagus corresponding to a calculated mesh area of 2811 mm(2) and a hole area of 214 mm(2) were implanted in nine German Landrace pigs. Six weeks later, the meshes were explanted and investigated for size, shrinkage, migration and adhesions. RESULTS: The total mesh area shrank to a mean of 2,040 +/- 178 mm(2) (p < 0.001), and the hole for the esophagus showed a trend toward an increase to 239 +/- 38 mm(2) (p = 0.108). In not a single location did the mesh overhang the hiatal margin. The mean distance of retraction from the hiatal margin was 4.3 +/- 2.8 mm. Therefore, no stenoses, migrations, or erosions occurred. CONCLUSIONS: A circular heavy-weight polypropylene mesh seems to be appropriate for the application at the esophageal hiatus in terms of safety and stability. This means that it is characterized by a position-stable centered fixation around the esophagus without a tendency toward stenosis, migration, or erosion.

Taurolidine reduces the tumor stimulating cytokine interleukin-1beta in patients with resectable gastrointestinal cancer: a multicentre prospective randomized trial.

BACKGROUND: The effect of additional treatment strategies with antineoplastic agents on intraperitoneal tumor stimulating interleukin levels are unclear. Taurolidine and Povidone-iodine have been mainly used for abdominal lavage in Germany and Europe. METHODS: In the settings of a multicentre (three University Hospitals) prospective randomized controlled trial 120 patients were randomly allocated to receive either 0.5% taurolidine/2,500 IU heparin (TRD) or 0.25% povidone-iodine (control) intraperitoneally for resectable colorectal, gastric or pancreatic cancers. Due to the fact that IL-1beta (produced by macrophages) is preoperatively indifferent in various gastrointestinal cancer types our major outcome criterion was the perioperative (overall) level of IL-1beta in peritoneal fluid. RESULTS: Cytokine values were significantly lower after TRD lavage for IL-1beta, IL-6, and IL-10. Perioperative complications did not differ. The median follow-up was 50.0 months. The overall mortality rate (28 vs. 25, p = 0.36), the cancer-related death rate (17 vs. 19, p = .2), the local recurrence rate (7 vs. 12, p = .16), the distant metastasis rate (13 vs. 18, p = 0.2) as well as the time to relapse were not statistically significant different. CONCLUSION: Reduced cytokine levels might explain a short term antitumorigenic intraperitoneal effect of TRD. But, this study analyzed different types of cancer. Therefore, we set up a multicentre randomized trial in patients undergoing curative colorectal cancer resection. TRIAL REGISTRATION: ISRCTN66478538.

Signs of reperfusion injury following CO2 pneumoperitoneum: an in vivo microscopy study.

BACKGROUND: During laparoscopic surgery, pneumoperitoneum is generally established by means of carbon dioxide (CO(2)) insufflation which may disturb hepatic microperfusion. It has been suggested that the desufflation at the end of the procedure creates a model of reperfusion in a previously ischemic liver, thus predisposing it to reperfusion injury. METHODS: To study the effects of pneumoperitoneum on hepatic microcirculation, Sprague-Dawley rats underwent pneumoperitoneum with an intraabdominal pressure of 8 or 12 mmHg for 90 min. Subsequently, in vivo microscopy was performed to assess intrahepatic microcirculation and transaminases were measured to index liver injury. RESULTS: A CO(2) pneumoperitoneum of 8 mmHg did not change serum transaminases; however, further increase of intraperitoneal pressure to 12 mmHg significantly increased AST, ALT, and LDH measured after desufflation to almost 1.5 times as much as control values of 49 +/- 5 U/L, 31 +/- 3 U/L, and 114 +/- 12 U/L. In parallel, in all subacinar zones the permanent adherence of both leukocytes and platelets to the endothelium increased by about sixfold and threefold, respectively. Furthermore, Kupffer cells labeled with latex beads as an index for their activation were significantly increased compared to controls. CONCLUSION: This in vivo observation demonstrated traces of reperfusion injury in liver induced by the insufflation and desufflation of CO(2 )pneumoperitoneum. The clinical relevance of this finding and the issue of using hepatoprotective substances to prevent this injury should be further investigated.

R2 resection in pancreatic cancer--does it make sense?

BACKGROUND: The goal of surgical treatment in patients with pancreatic cancer is the complete resection of tumor tissue; however, the intraoperative appraisal of resectability can be difficult. Extensive surgical exploration for definitive clear resectability may lead to R2 resections in single cases. PATIENTS: We analyzed 38 patients with pancreatic cancer with remaining macroscopic tumor tissue after pancreatic resection, as R0 resection was not possible. Patients were compared to 46 patients with unresectable cancer without distant metastases or peritoneal carcinomatosis, in which a bypass procedure was performed. RESULTS: Operating time and hospital stay were significantly longer after R2 resection. Intraoperative blood loss was significantly higher; and severe surgical complications and the need for relaparotomy were significantly more frequent after R2 resection. The 30-day mortality rate was higher after R2 resection; this difference was not statistically significant. Median survival was comparable in both groups. Two years after surgery, 22.6% of the patients after R2 resection were still alive compared to 10.9% after bypass surgery. CONCLUSION: Tumor debulking is not a treatment option in patients with advanced pancreatic cancer, but the patient is not at a disadvantage compared to bypass procedures if tumor tissue remains and R0 resection cannot be achieved after surgical exploration.

Robotic suturing: technique and benefit in advanced laparoscopic surgery.

Suturing is one of the main tasks in advanced laparoscopic surgery, but limited degrees of freedom, 2D vision, fulcrum and pivoting effect make it difficult to perform. Robotic systems provide corresponding solutions as three-dimensional (3D) view, intuitive motion and additional degrees of freedom. This review evaluates these benefits for their impact on suturing in experimental and clinical studies. The Medline database was searched for "robot*, telemanipulat* and laparoscop*". A total of 1150 references were found and further limited to "suturing" for experimental evaluation, finding 89 references. All references were considered for information on robotic suturing in advanced laparoscopy. Further references were obtained through cross-referencing the bibliography cited in each work. In experimental studies current robotic systems have proven their superior suturing capabilities compared to conventional laparoscopic techniques, mainly attributed to 3D visualization and full seven degrees of freedom. In clinical studies these benefits have not yet been sufficiently reproduced. Robotic systems have to prove the benefits shown in experimental studies for suturing tasks in clinical applications. Robotic devices shorten the learning curve of laparoscopic procedures. Further clinical trials focusing on anastomosis time are needed to assess this question.

Reversible biliary occlusion in a small animal model: first description of a new technique.

BACKGROUND: Experimental models with reversible biliary occlusion resulted in a high mortality of the animals, up to 20-60% according to the literature. Our aim was to assess a safe and valid technique for reversible biliary occlusion with a low mortality. METHODS: We randomized 30 rats into two groups: with bile duct occlusion (BDO, n=18) and with sham manipulation of the extrahepatic bile duct (control, n=12). We used a removable vascular clip for temporary occlusion of the extrahepatic bile duct. The clip was removed on postoperative day (POD) 2. On POD 2, 3, and 5, we measured the hepatocellular injury and metabolic function markers in serum. Activation of mononuclear cells (HIS36) and expression of regeneration markers [cytokeratin 19, hepatic growth factor (HGF)-α, and HGF-ß] were determined by immunohistochemistry. RESULTS: The survival rate was 96.67% (1/30); one animal died. The mortality in the BDO group was 6% (1/18) and that in the control group was 0% (0/12). BDO resulted in a sharp increase of hepatocellular injury and cholestatic parameters on POD 2 with a rapid decline till POD 3. Significantly strongest activation of Kupffer cells and expression of proliferation markers were found until POD 5 after BDO. CONCLUSION: The clip technique is a safe, cheap, and valid method for reversible biliary occlusion with an extremely low mortality.

Endoscopic posterior mesorectal resection as an option to combine local treatment of early stage rectal cancer with partial mesorectal lymphadenectomy.

BACKGROUND AND AIMS: Low anterior resection and abdominoperineal resection with total mesorectal excision are the standard treatment in patients with low rectal cancer. Rectal resection remains a surgical intervention with considerable morbidity and long-term impairment of quality of life. Local excision of low rectal cancer is regarded as an alternative to radical surgery; however, occurrence of lymph node metastasis even in patients with highly differentiated early-stage rectal cancer may be underestimated. PATIENTS AND RESULTS: In two patients with T1 rectal cancer, minimal-invasive partial excision of the mesorectum was performed after transanal excision of the tumor. The postoperative course was uneventful in both patients. Patients left the hospital on the fourth and fifth postoperative day without any complaints. In one patient, histo-pathological workup revealed a lymph node metastasis in the specimen. DISCUSSION: The technique of "Endoscopic posterior mesorectal resection" represents an interesting option in the surgical treatment of rectal cancer, as it allows for the first time an organ preserving resection of local lymph nodes in the small pelvis. It may evolve as an efficient new staging procedure to identify patients with metastatic disease who may benefit from multimodal treatment or extended surgery.

Correction: Use of Mesh in Laparoscopic Paraesophageal Hernia Repair: A Meta-Analysis and Risk-Benefit Analysis.

[This corrects the article DOI: 10.1371/journal.pone.0139547.].