Randomized controlled trial of robotic-assisted versus conventional laparoscopic fundoplication: 12 years follow-up.

AIMS: Numerous reports have addressed the feasibility and safety of robotic-assisted (RALF) and conventional laparoscopic fundoplication (CLF). Long-term follow-up after direct comparison of these two minimally invasive approaches is scarce. The aim of the present study was to assess long-term disease-specific symptoms and quality of life (QOL) in patients with gastroesophageal reflux disease (GERD) treated with RALF or CLF after 12 years in the randomized ROLAF trial. METHODS: In the ROLAF trial 40 patients with GERD were randomized to RALF (n = 20) or CLF (n = 20) between August 2004 and December 2005. At 12 years after surgery, all patients were invited to complete the standardized Gastrointestinal Symptom Rating Scale (GSRS) and the Quality of Life in Reflux and Dyspepsia questionnaire (QOLRAD). Failure of treatment was assessed according to Lundell score. RESULTS: The GSRS score was similar for RALF (n = 15) and CLF (n = 15) at 12 years´ follow-up (2.1 ± 0.7 vs. 2.2 ± 1.3, p = 0.740). There was no difference in QOLRAD score (RALF 6.4 ± 1.2; CLF 6.4 ± 1.5, p = 0.656) and the QOLRAD score sub items. Long-term failure of treatment according to the definition by Lundell was not different between RALF and CLF [46% (6/13) vs. 33% (4/12), p = 0.806]. CONCLUSION: In accordance with previous short-term outcome studies, the long-term results 12 years after surgery showed no difference between RALF and CLF regarding postoperative symptoms, QOL and failure of treatment. Relief of symptoms and patient satisfaction were high after both procedures on the long-term. REGISTRATION NUMBER: DRKS00014690 ( https://www.drks.de ).

Dissection with LigaSure Impact™ versus conventional resection in pylorus-preserving partial pancreatoduodenectomy (DISSECT): a single-institution randomized controlled trial.

PURPOSE: In partial pancreatoduodenectomy, appropriate effective hemostasis during dissection is of major importance for procedural flow, operation time, and postoperative outcome. As ligation, clipping, or suturing of blood vessels is time-consuming and numerous instrument changes are required, the primary aim of this randomized controlled trial was to assess whether LigaSure Impact™ exhibits benefits over named conventional dissection techniques in patients undergoing pylorus-preserving partial pancreatoduodenectomy. METHODS: This single-institution, randomized, superiority trial was performed between September 27, 2009, and February 24, 2012. Patients undergoing pylorus-preserving partial pancreatoduodenectomy were allocated to the study arms in a 1:1 ratio based on an unstratified block randomization with random block sizes to receive either dissection with LigaSure Impact™ or conventional dissection. The primary endpoint was operation time. Secondary endpoints included peri- and postoperative morbidity and mortality, intraoperative blood loss, and length of hospital stay. To observe a time reduction of 40 min, 51 patients per arm were required. The primary analysis was the intention to treat. RESULTS: The mean operation time did not differ between the Ligasure Impact™ (308 min; SD: 56 min; range: 155-455 min) and the conventional dissection (318 min; SD: 90 min, range: 175-550 min) (p = 0.531). Moreover, LigaSure Impact™ dissection did not show significant advantages over conventional dissection in terms of peri- and postoperative morbidity and mortality, intraoperative blood loss, or length of hospital stay. CONCLUSIONS: The application of LigaSure Impact™ dissection in pylorus-preserving partial pancreatoduodenectomy does not increase effectiveness and safety of dissection. TRIAL REGISTRATION: DRKS00000166.

Robotic-assisted paraesophageal hernia repair--a case-control study.

AIMS: The da Vinci® telemanipulation system offers a wide range of precise movements and 3D visualization with depth perception and magnification effect. Such a system could be useful for improving minimally invasive procedures-as in the case of large hiatal hernia with paraesophageal involvement (PEH) repair. Studies reporting on the robotic-assisted PEH repair are scarce, and a comparison to the standard operation techniques is lacking. Therefore, we decided to investigate the feasibility and safety of robotic-assisted surgery (RAS) compared to conventional laparoscopic (CLS) and open surgery (OS) for the first time. METHODS: We investigated 42 patients for the perioperative outcome after PEH repair. Twelve patients were operated on with RAS, 17 with CLS, and 13 with OS. Operating time, intraoperative blood loss, intra- and postoperative complications, mortality, and duration of hospital stay were analyzed in each method. RESULTS: On average, operating time in the RAS group was 38 min longer, and the intraoperative blood was loss 217 ml lower compared to OS. Both results were similar to the CLS group. The intraoperative complication rate was similar in all groups. The postoperative complication rate in the RAS group was significantly lower than the OS group, though again similar to the CLS group. The hospital stay was 5 days shorter in the RAS group than the OS group and once again similar to the CLS group. CONCLUSION: The results show that RAS is feasible and safe. It appears to be an alternative to OS due to lower intraoperative blood loss and potentially fewer postoperative complications, as well as shorter hospital stay. Though, RAS is not superior to CLS.

Comparison of two different transection techniques in liver surgery-an experimental study in a porcine model.

AIMS: Postoperative morbidity and mortality after liver resection is closely related to the degree of intraoperative blood loss; the majority of which occurs during transection of the liver parenchyma. Many approaches and devices have therefore been developed to limit bleeding, but none has yet achieved perfect results up to now. The aim of this standardized chronic animal study was to compare the safety and efficacy of the LigaSure™ Vessel Sealing System (LVSS) with the stapler technique, which is one of the modern techniques for transecting the parenchyma in liver surgery. METHODS: Sixteen pigs underwent a left liver resection (LLR). Eight pigs received a LLR by means of an Endo GIA, whereas the other eight pigs underwent liver parenchymal transection followed by simultaneous sealing by the LVSS. The operating time, transection time, blood loss during transection, and time of hemostasis were measured on the day of LLR (postoperative day 0/POD 0). Animals were re-explored on postoperative day 7 (POD 7) and the transection surface of remnant liver was observed for fluid collection (hematoma, biloma, and abscess), necrosis, and other pathologies. A biopsy was taken from the area of transection for histopathological examination. RESULTS: All animals survived until POD 7. Operating time and transection time of the liver parenchyma on POD 0 was significantly shorter in the stapler group. There was no significant difference between the two groups in terms of blood loss during transection, time of hemostasis and number of sutures for hemostasis on POD 0, morbidity rate, as well as the histopathological examination on POD 7. Furthermore, the material costs were significantly higher in the stapler group than in the LVSS group. CONCLUSION: In this standardized chronic animal study concerning transection of the parenchyma in liver surgery, LVSS seems not only to be safe, but also comparable with the stapler technique in terms of morbidity and mortality. Additionally, LVSS significantly reduces material costs. However, the transection time is significantly longer for LVSS than for the stapler resection technique.

Success and complication parameters for laparoscopic surgery: a benchmark for natural orifice transluminal endoscopic surgery.

BACKGROUND: Natural orifice transluminal endoscopic surgery (NOTES) currently represents an issue of particular interest among surgeons and gastroenterologists. The principle of NOTES is the reduction of the operative trauma by using natural orifices of the human body to access the abdominal cavity. Regarding the tendency to further minimization of the surgical trauma, NOTES may be considered as a logical step in the evolution of minimally invasive surgery. Pioneers of this technique regard NOTES as the successor to laparoscopic surgery in enabling surgeons and gastroenterologists to conduct scarless surgery. This might not only lead to better cosmetic results but also enhance the prospect of decreases in wound infections and incisional hernias, as well as reducing operative stress, postoperative immobility, and pain. MATERIAL AND METHODS: In this article the authors collect and review the existing literature concerning NOTES and establish a benchmark for the assessment of this new technique by stating results from conventional minimally invasive surgery as the gold standard. CONCLUSION: It is shown that publications investigating possible advantages or long-term results of NOTES are scarce. However, the investigation and verification of potential advantages and disadvantages represent the most important step in the development of a new technique. Only proven advantages would justify the broad implementation of a new technique in relation to its specific risks. Conventional laparoscopic surgery as the current standard of minimally invasive surgery will be the benchmark for NOTES with regard to most issues. Superiority of NOTES in at least several issues would be the best argument for its further implementation into clinical practice.

No relevant difference in quality of life and functional outcome at 12 months' follow-up-a randomised controlled trial comparing robot-assisted versus conventional laparoscopic Nissen fundoplication.

PURPOSE: The present randomised pilot trial was designed to compare robot-assisted (RALF) and conventional laparoscopic fundoplication (CLF) focussing on post-operative quality of life (QOL) and functional outcome. Any long-lasting advantages for patients in this regard could be a justification for the use of RALF for the treatment of gastroesophageal reflux disease (GERD). METHODS: Forty patients with GERD were randomised to either RALF or to CLF. During a follow-up period of 12 months, patients' QOL and functional outcome were investigated using disease-specific questionnaires. RESULTS: There were no significant differences in the mean QOL (1.3 versus 1.1; P = 0.374) and functional outcome (1.27 versus 1.3; P = 0.913) between both groups. Minor side effects such as bloating and persistent diarrhoea were present in four patients of each group. CONCLUSION: The present study did not show any benefit for RALF over CLF regarding QOL and functional outcome at 12 months' follow-up.

Gas-chamber mediastinoscopy for dissection of the upper esophagus.

AIM: Mediastinoscopy has the potential to bring under view the upper mediastinum, the area most difficult to dissect during transhiatal esophagectomy. The aim of the present study was to evaluate in an animal model the feasibility of the gas-chamber mediastinoscopy technique for dissection of the upper esophagus. METHODS: Operations were performed in nine Landrace pigs using a 30 degrees laparoscope and conventional 35-cm laparoscopic instruments. Through a left collar incision a virtual space was created with sharp and blunt dissection around the cervical esophagus and insufflated with CO2 at a pressure of 5 mmHg. Using one 10-mm optical trocar and two 5-mm working trocars dissection advanced in the periesophageal space with the aim to reach at least to the tracheal bifurcation. RESULTS: Performed under visual control, the procedure was accurate and safe, the level of tracheal bifurcation being reached in all cases. Anatomical structures such as trachea and its bifurcation, pleura, pericardium, arch of the azygos vein and periesophageal lymph nodes were visible during the operation. There were no major intraoperative incidents and blood loss was minimal. CONCLUSIONS: The technique of gas-chamber mediastinoscopy is feasible. It allows a fair amount of freedom of movement for the working instruments and offers a good view on the operative field for a controlled and accurate dissection. Further evaluation in experimental and clinical studies is required to establish the role of this procedure in esophageal surgery.

Evaluation of the combined laparoscopic and mediastinoscopic esophagectomy technique.

BACKGROUND: Laparoscopic esophagectomy is technically difficult especially during dissection in the upper mediastinum. This limitation may be surpassed with the help of mediastinoscopy or of the recently introduced robotic surgical systems. The aim of the present study was to evaluate in an experimental porcine model the feasibility of the combined laparoscopic and mediastinoscopic transhiatal esophagectomy technique and to compare it with the robotic-assisted transhiatal and conventional approaches. MATERIALS AND METHODS: Transhiatal esophagectomy was performed in Landrace pigs under general anesthesia using three different techniques: Group A (n = 9): combined laparoscopic and mediastinoscopic, group B (n = 4): robotic-assisted and group C (n = 8): conventional "open". The feasibility, difficulty and accuracy of the procedure along with operative time, blood loss, intraoperative incidents and overall satisfaction of the surgical team were assessed for each technique. RESULTS: Operations in group A were feasible and reproducible. Although the procedure was technically difficult, the constant view on the operative field was highly appreciated by the operative team and facilitated an accurate and safe dissection. The main intraoperative complications were related to the side-effects of tension pneumothorax accompanying pleural injuries. In group B the features of the robotic system reduced the difficulty of dissection and obviated the need for mediastinoscopy. Operations in group C were quick and almost incident-free, facilitated also by the particularities of the animal model that could not reproduce identically the clinical situation. CONCLUSIONS: The combined laparoscopic and mediastinoscopic esophagectomy technique is feasible and offers certain advantages over the open approach while the robotic-assisted approach is an emerging less difficult alternative. Further studies are required to establish whether the advantages of minimally-invasive approach compensate for the increased technical difficulty and prolonged operative time.

Development of a navigation system for minimally invasive esophagectomy.

BACKGROUND: A major challenge of minimally invasive esophagectomy is the uncertainty about the exact location of the tumor and associated lymph nodes. This study aimed to develop a navigation system for visualizing surgical instruments in relation to the tumor and anatomic structures in the chest. METHODS: An immobilization device consisting of a vacuum mattress fixed to a stretcher was built to decrease patient movement and organ deformation. Computer tomography (CT) markers were embedded in the stretcher at a defined distance to a detachable plate with optical markers on the side of the stretcher. A second plate of optical markers was fixed to the operating instrument. These two optical marker plates were tracked with an optical tracking system. Their positions were then registered in a preoperative CT data set using the authors' navigation software. This allowed a real-time visualization of the instrument and target structures. To assess the accuracy of the system, the authors designed a phantom consisting of a box containing small spheres in a specific three-dimensional layout. The positions of the spheres were first measured with the navigation system and then compared with the known real positions to determine the accuracy of the system. RESULTS: In the accuracy assessment, the navigation system showed a precision of 0.95 +/- 0.78 mm. In a test data set, the instrument could be successfully navigated to the tumor and target structures. CONCLUSION: The described navigation system provided real-time information about the position and orientation of the working instrument in relation to the tumor in an experimental setup. Consequently, it might improve minimally invasive esophagectomy and allow for surgical dissection in an adequate distance to the tumor margin and ease the location of affected lymph nodes.

Creation and establishment of a respiratory liver motion simulator for liver interventions.

Image-guided surgery and navigation have resulted from convergent developments in radiology, teletransmission, and computer science and are well-established procedures in the surgical routine in orthopedic, neurosurgery, and head-and-neck surgery. In abdominal surgery, however, these tools have gained little attraction so far. The inability to transfer the methodology from orthopedic or neurosurgery is mainly a result of intraoperative organ movement and shifting. To practice and establish navigated interventions in the liver, a custom-designed respiratory liver motion simulator was built which models the human torso and is easy to recreate. To simulate breathing motion, an explanted porcine or human liver is mounted to the diaphragm model of the simulator, and a lung ventilator causes a periodic movement of the liver along the craniocaudal axis. Additionally, the liver can be connected to a circulating pump device which simulates hepatic perfusion and provides real surgical options to establish navigated interventions and simulate management of possible complications. Respiratory motion caused by the simulator was evaluated with an optical tracking system and it was shown that in vitro movement and deformation of a liver mounted to the device are similar to the liver movements in human or porcine bodies. Based on the tests, it is concluded that the novel respiratory liver motion simulator is suitable for in vitro evaluation of navigated systems and interventional and surgical procedures.

Robot-assisted versus conventional laparoscopic fundoplication: short-term outcome of a pilot randomized controlled trial.

BACKGROUND: Robotic technology represents the latest development in minimally-invasive surgery. Nevertheless, robotic-assisted surgery seems to have specific disadvantages such as an increase in costs and prolongation of operative time. A general clinical implementation of the technique would only be justified if a relevant improvement in outcome could be demonstrated. This is also true for laparoscopic fundoplication. The present study was designed to compare robotic-assisted (RALF) and conventional laparoscopic fundoplication (CLF) with the focus on operative time, costs und perioperative outcome. METHODS: Forty patients with gastro-esophageal reflux disease were randomized to either RALF by use of the daVinci Surgical System or CLF. Nissen fundoplication was the standard anti-reflux procedure. Peri-operative data such as length of operative procedure, intra-and postoperative complications, length of hospital stay, overall costs and symptomatic short-term outcome were compared. RESULTS: The total operative time was shorter for RALF compared to CLF (88 vs. 102 min; p = 0.033) consisting of a longer set-up (23 vs. 20 min; p = 0.050) but a shorter effective operative time (65 vs. 82 min; p = 0.006). Intraoperative complications included one pneumothorax and two technical problems in the RALF group and two bleedings in the CLF group. There were no conversions to an open approach. Mean length of hospital stay (2.8 vs. 3.3 days; p = 0.086) and symptomatic outcome thirty days postoperatively (10% vs. 15% with ongoing PPI therapy; p = 1.0 and 25% vs. 20% with persisting mild dysphagia; p = 1.0) was similar in both groups. Costs were higher for RALF than for CLF (3244 euros vs. 2743 euros, p = 0.003). CONCLUSION: In comparison with CLF, operative time can be shorter for RALF if performed by an experienced team. However, costs are higher and short-term outcome is similar. Thus, RALF can not be favoured over CLF regarding perioperative outcome.

Taurine protects from liver injury after warm ischemia in rats: the role of kupffer cells.

BACKGROUND/AIMS: Warm ischemia to liver with subsequent Kupffer cell-dependent pathology is associated with many clinical conditions. Taurine prevents Kupffer cell activation and improves graft survival after experimental cold ischemia and liver transplantation. Thus this study was designed to assess its effects after warm hepatic ischemia. METHODS: The left liver lobe of female Sprague-Dawley rats (170-210 g) underwent 60 min of warm ischemia. Animals were given either intravenous taurine or Ringer's solution 10 min prior to warm ischemia. Transaminases, histology, in vivo microscopy, intercellular adhesion molecules-1 (ICAM-1) expression, TNF-alpha and tissue hydroperoxide were compared between groups using analysis of variance (ANOVA) or ANOVA on ranks as appropriate. RESULTS: Taurine significantly decreased transaminases and improved histologic outcome. Phagocytosis of latex beads, serum TNF-alpha levels and tissue hydroperoxide concentrations were also significantly reduced. Stickers in sinusoids and post-sinusoidal venules significantly decreased. In parallel, both leukocyte infiltration and ICAM-1 expression decreased (p < 0.05), while flow velocity of red blood cells as well as sinusoidal perfusion rate were improved (p < 0.05). CONCLUSION: This study demonstrates that taurine blunts Kupffer cell-dependent hepatic pathology after warm ischemia in vivo via mechanisms including leukocyte-endothelial interaction, microcirculation disturbances and protection against lipid peroxidation.

Effect of a pneumoperitoneum on systemic cytokine levels, bacterial translocation, and organ complications in a rat model of severe acute pancreatitis with infected necrosis.

BACKGROUND: Infection of pancreatic necrosis (IPN) is strongly associated with sepsis and multiple organ dysfunction and is an absolute indication for surgery. Patients with IPN are critically ill at the time of surgery and may benefit from a minimally invasive approach with reduced surgical trauma. Recently, several minimally invasive necrosectomy techniques have been reported. However, the effects and potential dangers of a pneumoperitoneum in IPN cases are unknown. This study aimed to determine the effects of a pneumoperitoneum on systemic cytokine levels, bacterial translocation, and systemic organ complications in a rat model of IPN. METHODS: For this study, IPN was induced in Wistar rats using retrograde intraductal infusion of 3% taurocholate. After 8 h, the animals were subjected to either laparoscopy (pneumoperitoneum at 8 mmHg) or laparotomy for 1 h and killed after 1 or 3 h. Severe acute pancreatitis with IPN was proved by serum amylase and lipase, histology, tissue activity of myeloperoxidase (MPO), and bacteriology. Systemic levels for interleukin-10 (IL-10), IL-6, tumor necrosis factor-alpha (TNF-alpha), and lipopolysaccarides were determined by enzyme-linked immunoassay (ELISA). Systemic organ damage and dysfunction were evaluated using MPO activity (lung), serum creatinine (kidney), and serum aminotransferases (liver). RESULTS: Necrotizing pancreatitis developed in all the animals. Most of the animals (85%) had proven infected necrosis. Elevated cytokine levels and deteriorated organ parameters demonstrated systemic inflammation and organ failure. Although there was a tendency toward a higher level of proinflammatory cytokines after laparotomy, there were no significant differences between laparotomy and laparoscopy. Furthermore, these alterations were not accompanied by any differences in bacterial translocation (lipopolysaccharides), systemic organ damage, or mortality between laparoscopy and laparotomy. CONCLUSION: In the current model of infected pancreatic necrosis, a pneumoperitoneum did not result in increased cytokine release or bacterial translocation. However, the putative advantage of less surgical trauma with the laparoscopic approach did not play a significant role in the setting of severe acute pancreatitis with IPN.

Development and evaluation of a training module for the clinical introduction of the da Vinci robotic system in visceral and vascular surgery.

BACKGROUND: With the increasing use of the surgical robotic system in the clinical arena, appropriate training programs and assessment systems need to be established for mastery of this new technology. The authors aimed to design and evaluate a clinic-like training program for the clinical introduction of the da Vinci robotic system in visceral and vascular surgery. METHODS: Four trainees with different surgical levels of experience participated in this study using the da Vinci telemanipulator. Each participant started with an initial evaluation stage composed of standardized visceral and vascular operations (cholecystectomy, gastrotomy, anastomosis of the small intestine, and anastomosis of the aorta) in a porcine model. Then the participants went on to the training stage with the rat model, performing standardized visceral and vascular operations (gastrotomy, anastomosis of the large and small intestines, and anastomosis of the aorta) four times in four rats. The final evaluation stage was again identical to the initial stage. The operative times, the number of complications, and the performance quality of the participants were compared between the two evaluation stages to assess the impact of the training stage on the results. RESULTS: The operative times in the final evaluation stage were considerably shorter than in the initial evaluation stage and, except for cholecystectomies, all the differences reached statistical significance. Also, significantly fewer complications and improved quality for each operation in the final evaluation stage were documented, as compared with their counterparts in the initial evaluation stage. These improvements were recorded at each level of experience. CONCLUSIONS: The presented experimental small and large animal model is a standardized and reproducible training method for robotic surgery that allows evaluation of the surgical performance while shortening and optimizing the learning-curve.

Evaluation of microperfusion disturbances in the transplanted liver after Kupffer cell destruction using GdCl3: an experimental porcine study.

BACKGROUND: Organ function after liver transplantation is determined by ischemia-reperfusion injury. Destruction of Kupffer cells with gadolinium chloride (GdCl3) has been shown to have a possible preventive effect on the extent of this injury, which can be extrapolated by analyzing the distribution of hepatic microperfusion. The aim of this study was to evaluate the protective effect of GdCl3 on disturbances of microperfusion in the transplanted liver. METHODS: Landrace pigs were randomly divided into three groups. In the control group (CG; n=6) a mapping of the native liver was conducted. For mapping, the four hepatic liver lobes were named from right to left with A to D and every lobe was divided into three vertical segments (cranial, medial, and caudal). In each of these 12 areas, microperfusion was quantified using a thermodiffusion probe (TD [mL/100 g/min]). The other two groups were considered as transplanted treated group (TTG; n=10) and transplanted nontreated group (TnTG; n=10). The TTG received an infusion of 20 mg/kg GdCl3 intravenously 24 hours before organ harvesting. Then standardized orthotopic liver transplantation was performed. In TnTG, standardized orthotopic liver transplantation was carried out without prior GdCl3 injection. In the recipients, the microperfusion of transplanted livers were mapped in both TnTG and TTG, in two different time points (1 hour [n=5] and 24 hours (n=5]) after reperfusion. RESULTS: A significant reduction of macrophages in the TTG livers in comparison to the CG and TnTG livers was observed (P<.05). However, the number of macrophages in CG and TnTG livers showed no significant difference (P>.05). Regarding liver microperfusion, in TnTG, a marked heterogeneity was detected in the livers after reperfusion. Significant differences between liver lobes (horizontal planes; P=.032) and vertical layers of intralobar liver parenchyma (P=.029) were observed. The same pattern was seen in TTG livers after reperfusion and a significant difference between horizontal (P=.024) and vertical layers (P=.018) of liver tissue were observed. Comparing intralobar regional flow data between vertical planes 24 hours after reperfusion still showed a prominent variation of hepatic tissue perfusion in TnTG livers (P=.028). Within the same horizontal layers, no significant differences between lobes were measured anymore (P=.16). Contrary to TnTG, in TTG, a homogenous pattern of regional liver tissue perfusion was recorded 24 hours after reperfusion. Comparison of TD data on the liver regions showed no significant microperfusion differences in either horizontal (P=.888) or vertical (P=.841) layers. CONCLUSIONS: Application of GdCl3 resulted in a significant reduction of Kupffer cells. Twenty four hours after transplantation microperfusion showed a homogeneous pattern, which constituted an earlier and better recovery of the transplanted liver. Therefore, destruction of Kupffer cells reduced ischemia-reperfusion injury and seemed to be responsible for the early recovery of microperfusion disturbances and thus for an improvement of graft function.

[Postoperative ileus. Pathophysiology and prevention]. / Postoperativer Ileus. Pathophysiologie und Prävention.

Continuous improvements in surgical technique and anaesthesia for ileus have resulted in a significant reduction of perioperative complications. Postoperative outcome of surgical patients is increasingly dependent on the severity of postoperative ileus, which often determines morbidity and length of hospital stay. In the present article we discuss possible variables influencing this disease. Furthermore, means of prevention and therapeutic strategies for postoperative ileus are briefly presented.

A review of various techniques of orthotopic liver transplantation in the rat.

Orthotopic liver transplantation (OLT) in rat is a demanding procedure, which has become a popular model to investigate various problems. Our aim was to review and analyze the various techniques of experimental OLT in the rat. A review of the literature revealed 30 techniques or technical modifications. Each modification represented a change or a simplification of the reconstruction method of five anatomical structures, which are cornerstones of a successful OLT: the suprahepatic inferior vena cava (SHVC), portal vein (PV), infrahepatic inferior vena cava (IHVC), hepatic artery (HA), and bile duct (BD). SHVC is anastomosed via microsuture or cuff. The PV anastomosis is performed by microsuture, cuff, or a microsuture-temporary splint technique. IHVC is reconstructed by a microsuture, cuff, or microsuture-temporary splint technique. Arterialization has been accomplished via microsuture (aortic segment, celiac segment, or aortic patch), cuff, splint, sleeve, or telescopic method. Nonarterialization of the graft has also been described. Methods for BD reconstruction include pull-through, telescopic, splint, and T-tube. Although a high level of microsurgical skill is the basic requirement in the microsuture technique which provides the most physiological situation and concomitantly reduces thrombosis, it increases anhepatic time compared to the cuff procedure. The learning curve of microsuture techniques is flat; beginners need much practice to become expert. The most physiologic techniques for anastomoses are preferred for long-term survival studies, while the faster techniques are options for short-term survival studies. Each research group must choose techniques according to study defined aims.

Laparoscopic organ retrieval for living donor liver transplantation does not prevent graft injury.

The cause of transplant failure may be difficult to define. However, organ retrieval before preservation and transplantation is an important factor. Organ manipulation during harvesting, which is inevitable with most techniques, leads to injury upon reperfusion including microcirculatory disturbances. Recently, laparoscopic organ retrieval has been successfully performed for human living donor liver transplantation (LDLT). Pneumoperitoneum for laparoscopy changes the pattern of hepatic blood flow. To study the effects of pneumoperitoneum on the graft prior to cold storage, livers from Sprague-Dawley rats underwent pneumoperitoneum with an intra-abdominal pressure of 8 mm Hg for 90 minutes. Subsequently, intravital microscopy was performed to assess intrahepatic microcirculation and transaminases were measured. Serum transaminases increased 1.5-fold compared with sham controls (P < .05). Intrahepatic microcirculation was significantly disturbed immediately after pneumoperitoneum. If this is confirmed in humans, laparoscopic organ retrieval for LDLT would be expected to decrease graft quality and not be beneficial in liver transplantation.

Guidelines for prevention and management of complications following kidney transplantation in rats.

Kidney transplantation in rats is a useful model for microsurgery, transplantation, and immunology studies. Our aim was to analyze various techniques of kidney transplantation in rats with emphasis on guidelines for the prevention and management of complications. Complications were categorized into general, vascular, and urological types and respectively attributed to long transplantation time, core body temperature drop, nonreplaced intraoperative blood loss, anastomosis failure, and ureteral anastomoses with stents or cannulas, which increase the risk of calculus formation. In conclusion, to decrease the complication rates the animal should be placed on a heating pad. For hemodynamic stability NaCl should be administered subcutaneously. To reduce the risk of thrombosis, ice-cold saline containing heparin should be administered. Vascular complications, which mainly depend on the microsurgeon's expertise, can be prevented by meticulous surgical technique (preferably an end-in-end anastomosis). The main urinary complications can be minimized by avoiding stents and cannulas and focusing on using techniques like the bladder-patch technique.

Carbon dioxide pneumoperitoneum is associated with increased liver metastases in a rat model.

BACKGROUND: In patients with primary colorectal cancer, liver metastases are the most important indicators of prognosis and survival; the effect of laparoscopic surgery on the development of hepatic tumor spread is still largely unknown. METHODS: Thirty WAG/Rij rats were randomly divided into 3 operative groups for intraportal tumor cell inoculation: carbon dioxide pneumoperitoneum (group I, n = 10), gasless laparoscopy (group II, n = 10) and open laparotomy (group III, n = 10). The total operating time was 90 minutes with tumor cell injection (50,000 CC531 colon carcinoma cells/mL) performed 45 minutes after the start of the procedure. Hepatic tumor growth and the total tumor load were evaluated 28 days after surgery. RESULTS: Hepatic tumor growth and total tumor load were significantly reduced in the gasless laparoscopy group (group II) as compared with the carbon dioxide pneumoperitoneum group (group I) and the open laparotomy group (group III) (P < .05). No significant difference was found between the carbon dioxide and the open laparotomy groups. CONCLUSIONS: Insufflation of carbon dioxide may actually stimulate metastatic disease of the liver. Gasless laparoscopy seems to preserve hepatic resistance against tumor growth.