[TULC - total umbilical laparoscopic cholecystectomy]. / TULC - Total Umbilikale Laparoskopische Cholezystektomie.

BACKGROUND: Except for some few cases only symptomatic cholecystolithiasis constitutes an indication for operative treatment. The gold standard meanwhile has been the laparoscopic cholecystectomy, because the method shows good results with short hospital stay. Recently there has been an intensive discussion about combination of laparoscopic techniques with natural body orifice using surgery (NOTES). These techniques permit further reduction of surgical trauma and enhancing of cosmetic results. However, the technical effort is significant and most of the times a combination (hybrid procedure) of NOTES with standard laparoscopic procedure is performed, so that we concentrated on performing a laparoscopic cholecystectomy using a single incision through the umbilicus. METHODS: A 5-mm incision left deep in the umbilicus and a 10-mm incision directly below were used for creating a pneumoperitoneum and for inserting the ports for the optic and the dissector. Exposition of the gallbladder was carried out by sutures, that were penetrated from outside through the abdominal wall into the abdominal cavity and transfixed through the gallbladder in order to hang up the gallbladder like a puppet by penetrating the abdominal wall again to the outside. Removal occurred through the umbilical incision. RESULTS: We successfully operated on 90  patients in a 12-month period. Mean operating time was 48 (39-71) min whereby no conversion to open surgery was necessary. No intra- or postoperative complications occurred in any patient. Average hospital stay was 2.5 (2-4) days, postoperative examination showed no differences to the usual laparoscopic cholecystectomy with a good cosmetic result and no visible scars. CONCLUSION: The purpose of our study was to further improve the cosmetic results of minimally invasive surgery of the gallbladder by operating totally through the umbilicus, using 2  ports deep in the umbilicus. We thereby avoid further surgical trauma due to creating an access through another organ as is done in the NOTES technique. For this operation no special equipment like flexible endoscopes was needed as common laparoscopic instruments were used.

Chemoradiotherapy with concurrent gemcitabine and cisplatin with or without sequential chemotherapy with gemcitabine/cisplatin vs chemoradiotherapy with concurrent 5-fluorouracil in patients with locally advanced pancreatic cancer--a multi-centre randomised phase II study.

BACKGROUND: No standard treatment for locally advanced pancreatic cancer (LAPC) is defined. PATIENTS AND METHODS: Within a multi-centre, randomised phase II trial, 95 patients with LAPC were assigned to three different chemoradiotherapy (CRT) regimens: patients received conventionally fractionated radiotherapy of 50 Gy and were randomised to concurrent 5-fluorouracil (350 mg m(-2) per day on each day of radiotherapy, RT-5-FU arm), concurrent gemcitabine (300 mg m(-2)), and cisplatin (30 mg m(-2)) on days 1, 8, 22, and 29 (RT-GC arm), or the same concurrent treatment followed by sequential full-dose gemcitabine (1000 mg m(-2)) and cisplatin (50 mg m(-2)) every 2 weeks (RT-GC+GC arm). Primary end point was the overall survival (OS) rate after 9 months. RESULTS: The 9-month OS rate was 58% in the RT-5-FU arm, 52% in the RT-GC arm, and 45% in the RT-GC+GC arm. Corresponding median survival times were 9.6, 9.3, and 7.3 months (P=0.61) respectively. The intent-to-treat response rate was 19, 22, and 13% respectively. Median progression-free survival was estimated with 4.0, 5.6, and 6.0 months (P=0.21). Grade 3/4 haematological toxicities were more frequent in the two GC-containing arms, no grade 3/4 febrile neutropaenia was observed. CONCLUSION: None of the three CRT regimens tested met the investigators' definition for efficacy; the median OS was similar to those previously reported with gemcitabine alone in LAPC.

The use of water-jet dissection in open and laparoscopic liver resection.

BACKGROUND: We intend to give an overview of our experiences with the implementation of a new dissection technique in open and laparoscopic surgery. METHODS: Our database comprises a total of 950 patients who underwent liver resection. Three hundred and fifty of them were performed exceptionally with the water-jet dissector. Forty-one laparoscopic partial liver resections were accomplished. RESULTS: Using the water-jet dissection technique it was possible to reduce the blood loss, the Pringle- and resection time in comparison to CUSA and blunt dissection. In the last five years we could reduce the Pringle-rate from 48 to 6% and the last 110 liver resections were performed without any Pringle's manoeuvre. At the same time, the transfusion-rate decreased from 1.86 to 0.46 EC/patient. In oncological resections, the used dissection technique had no influence on long-time survival. CONCLUSIONS: The water-jet dissection technique is fast, feasible, oncologically safe and can be used in open and in laparoscopic liver surgery.

[Diagnosis and treatment of colorectal liver metastases - workflow]. / Diagnostik und Therapie von Lebermetastasen kolorektaler Karzinome - Workflow.

In this review, standards of diagnosis and treatment of colorectal liver metastases are described on the basis of a workshop discussion. Algorithms of care for patients with synchronous / metachronous colorectal liver metastases or locoregional recurrent tumour are presented. Surgical resection is the procedure of choice in the curative treatment of liver metastases. The decision about the resection of liver metastases should consider the following parameters: 1. General operability of the patient (comorbidity); 2. Achievability of an R 0 situation: i. if necessary, in combination with ablative methods, ii. if necessary, neoadjuvant chemotherapy, iii. the ability to eradicate extrahepatic tumour manifestations; 3. Sufficient volume of the liver remaining after resection ("future liver remnant = FLR): i. if necessary, in combination with portal vein embolisation or two-stage hepatectomy; 4. The feasibility to preserve two contiguous hepatic segments with adequate vascular inflow and outflow as well as biliary drainage; 5. Tumour biological aspects ("prognostic variables"); 6. Experience of the surgeon and centre! Extrahepatic disease does not contraindicate hepatectomy for colorectal liver metastases provided a complete resection of both intra- and extrahepatic disease is feasible. Even in bilobar colorectal metastases and 5 or more tumours in the liver, a complete tumour resection has been described. The type of resection (hepatic wedge resection or anatomic resection) does not influence the recurrence rate. Preoperative volumetry is indicated when major hepatic resection is planned. The FLR should be 25 % in patients with normal liver, 40 % in patients who have received intensive chemotherapy or in cases of fatty liver, liver fibrosis or diabetes, and 50-60 % in patients with cirrhosis. In patients with initially unresectable colorectal liver metastases, preoperative chemotherapy enables complete resection in 15-30 % of the cases, whereas the value of neoadjuvant chemotherapy in patients with resectable liver metastases has not been sufficiently supported. In situ ablative procedures (radiofrequency ablation = RFA and laser-induced interstitial thermotherapy = LITT) are local therapy options in selected patients who are not candidates for resection (central recurrent liver metastases, bilobar multiple metastases and high-risk resection or restricted patient operability). Patients with tumours larger than 3 cm have a high local recurrence rate after percutaneous RFA and are not optimal candidates for this procedure. The physician's experience influences the results significantly, both after hepatectomy and after in situ ablation. Therefore, patients with colorectal liver metastases should be treated in centres with experience in liver surgery.

Ischemic preconditioning attenuates portal venous plasma concentrations of purines following warm liver ischemia in man.

BACKGROUND/AIMS: Degradation of adenine nucleotides to adenosine has been suggested to play a critical role in ischemic preconditioning (IPC). Thus, we questioned in patients undergoing partial hepatectomy whether (i) IPC will increase plasma purine catabolites and whether (ii) formation of purines in response to vascular clamping (Pringle maneuver) can be attenuated by prior IPC. METHODS: 75 patients were randomly assigned to three groups: group I underwent hepatectomy without vascular clamping; group II was subjected to the Pringle maneuver during resection, and group III was preconditioned (10 min ischemia and 10 min reperfusion) prior to the Pringle maneuver for resection. Central, portal venous and arterial plasma concentrations of adenosine, inosine, hypoxanthine and xanthine were determined by high-performance liquid chromatography. RESULTS: Duration of the Pringle maneuver did not differ between patients with or without IPC. Surgery without vascular clamping had only a minor effect on plasma purine concentrations. After IPC, plasma concentrations of purines transiently increased. After the Pringle maneuver alone, purine plasma concentrations were most increased. This strong rise in plasma purines caused by the Pringle maneuver, however, was significantly attenuated by IPC. When portal venous minus arterial concentration difference was calculated for inosine or hypoxanthine, the respective differences became positive in patients subjected to the Pringle maneuver and were completely prevented by preconditioning. CONCLUSION: These data demonstrate that (i) IPC increases formation of adenosine, and that (ii) the unwanted degradation of adenine nucleotides to purines caused by the Pringle maneuver can be attenuated by IPC. Because IPC also induces a decrease of portal venous minus arterial purine plasma concentration differences, IPC might possibly decrease disturbances in the energy metabolism in the intestine as well.

Effects of Pringle manoeuvre and ischaemic preconditioning on haemodynamic stability in patients undergoing elective hepatectomy: a randomized trial.

BACKGROUND: The Pringle manoeuvre and ischaemic preconditioning are applied to prevent blood loss and ischaemia-reperfusion injury, respectively, during liver surgery. In this prospective clinical trial we report on the intraoperative haemodynamic effects of the Pringle manoeuvre alone or in combination with ischaemic preconditioning. METHODS: Patients (n=68) were assigned randomly to three groups: (i) resection with the Pringle manoeuvre; (ii) with ischaemic preconditioning before the Pringle manoeuvre for resection; (iii) without pedicle clamping. RESULTS: Following the Pringle manoeuvre the mean arterial pressure increased transiently, but significantly decreased after unclamping as a result of peripheral vasodilation. Ischaemic preconditioning improved cardiovascular stability by lowering the need for catecholamines after liver reperfusion without affecting the blood sparing benefits of the Pringle manoeuvre. In addition, ischaemic preconditioning protected against reperfusion-induced tissue injury. CONCLUSIONS: Ischaemic preconditioning provides both better intraoperative haemodynamic stability and anti-ischaemic effects thereby allowing us to take full advantage of blood loss reduction by the Pringle manoeuvre.

[Acute liver failure in nefazodone therapy? A case report]. / Akutes Leberversagen unter Nefazodon-Therapie? Ein Fallbericht.

Antidepressant-induced hepatotoxicity is generally considered of minimal clinical importance and is not well recognized. We report on a patient with recurrent major depression who was treated with nefazodone. Six weeks after initiation of therapy with nefazodone, he developed fatal liver failure. After cessation of the drug, the patient did not recover. He underwent liver transplantation but unfortunately died.

Recent advances in minimally invasive colorectal cancer surgery.

Laparoscopy has improved surgical treatment of various diseases due to its limited surgical trauma and has developed as an interesting therapeutic alternative for the resection of colorectal cancer. Despite numerous clinical advantages (faster recovery, less pain, fewer wound and systemic complications, faster return to work) the laparoscopic approach to colorectal cancer therapy has also resulted in unusual complications, i.e. ureteral and bladder injury which are rarely observed with open laparotomy. Moreover, pneumothorax, cardiac arrhythmia, impaired venous return, venous thrombosis as well as peripheral nerve injury have been associated with the increased intraabdominal pressure as well as patient's positioning during surgery. Furthermore, undetected small bowel injury caused by the grasping or cauterizing instruments may occur with laparoscopic surgery. In contrast to procedures performed for nonmalignant conditions, the benefits of laparoscopic resection of colorectal cancer must be weighed against the potential for poorer long-term outcomes of cancer patients that still has not been completely ruled out. In laparoscopic colorectal cancer surgery, several important cancer control issues still are being evaluated, i.e. the extent of lymph node dissection, tumor implantation at port sites, adequacy of intraperitoneal staging as well as the distance between tumor site and resection margins. For the time being it can be assumed that there is no significant difference in lymph node harvest between laparoscopic and open colorectal cancer surgery if oncological principles of resection are followed. As far as the issue of port site recurrence is concerned, it appears to be less prevalent than first thought (range 0-2.5%), and the incidence apparently corresponds with wound recurrence rates observed after open procedures. Short-term (3-5 years) survival rates have been published by a number of investigators, and survival rates after laparoscopic surgery appears to compare well with data collected after conventional surgery for colorectal cancer. However, long-term results of prospective randomized trials are not available. The data published so far indicate that the oncological results of laparoscopic surgery compare well with the results of the conventional open approach. Nonetheless, the limited information available from prospective studies leads us to propose that minimally invasive surgery for colorectal cancer surgery should only be performed within prospective trials.

[Surgical therapy of locally advanced and primary inoperable pancreatic carcinoma after neoadjuvant preoperative radiochemotherapy]. / Chirurgische Therapie des lokal fortgeschrittenen und primär inoperablen Pankreaskarzinoms nach neoadjuvanter präoperativer Radiochemotherapie.

INTRODUCTION: So far, surgery represents the only prospect for cure in patients with pancreatic cancer. Most patients, however, present with locally advanced pancreatic cancer at primary diagnosis. Recently, novel therapeutic regimens with preoperative radiochemotherapy have been developed that may improve long-term survival and resectability rates of patients with locally advanced pancreatic cancer. METHODS: This feasibility study evaluates the preliminary results of neoadjuvant therapy with gemcitabine and 5-fluorouracil (5-FU) or cisplatin. Twenty-six patients suffering from locally advanced pancreatic cancer were considered for preoperative radiochemotherapy. They received radiation (45 Gy) and chemotherapy with simultaneous or sequential gemcitabine and 5-FU (n = 15) or gemcitabine and cisplatin (n = 11) administration prior to surgical resection. RESULTS: Mean patient age was 62.4 +/- 2.6 years and 62% (n = 16) were male. The response rate was 69%, and 11 patients underwent curative surgical resection of the pancreatic cancer. Nine Whipple procedures and two complete pancreatectomies were carried out. In five patients a total of eight surgical complications were observed. Median overall survival was 9.8 months after primary cancer diagnosis (mean 12.0 +/- 1.2). During follow-up no local recurrent disease was detected. CONCLUSIONS: Our findings lead us to conclude that preoperative chemoradiation with 45 Gy, gemcitabine and 5-FU or cisplatin is a powerful therapeutic tool in patients with locally advanced non-resectable pancreatic cancer. Major resections, including vascular reconstructions, are nonetheless associated with increased mortality. Preoperative chemoradiation contributes to improved survival in patients with primary non-resectable pancreatic cancer.

[Perioperative antimicrobial prophylaxis for colonic surgery: Present status in Germany. A prospective multicenter study with and without Metronidazole]. / Perioperative Infektionsprophylaxe in der elektiven Kolonchirurgie: Klinischer Alltag in Deutschland - Eine multizentrische prospektive Studie mit versus ohne Metronidazol -

INTRODUCTION: The objective of a multicentric observational study, that was performed in Germany between 1(st) September 1996 and 30(th) September 1997, was to assess postoperative infections as a function of risk factors and antibiotic prophylaxis under everyday clinical conditions. 2 481 patients from 114 centres who received infection prophylaxis prior to elective colonic resection were included. In the descriptive analysis of the study it was noted that 36.1 % of the patients had received no prophylaxis with metronidazole despite the fact that the study protocol recommended the use of this drug in preoperative antibiotic combinations. The present analysis therefore considers the influence of metronidazole on the postoperative infection rate. METHODS: In order to exclude any bias due to intergroup differences in risk profile, the groups with and without metronidazole were subjected to a matched-pair analysis. Matching parameters were: duration of operation, blood loss, age, diabetes mellitus, hepatic, renal, or chronic airways disease, immunosuppressive therapy, and rectal resection. This led to the formation of 800 pairs that were matched with respect to these parameters. The 800 pairs were then stratified into the following treatment groups: Group 1 a and b: long-acting cephalosporine (ceftriaxone) with or without metronidazole (n = 2 x 491); Group 2 a and b: short-acting cephalosporines with or without metronidazole (n = 2 x 133); Group 3 a and b: broad-spectrum penicillines with or without metronidazole (n = 2 x 176). RESULTS: In all three treatment groups combination therapy with metronidazole was found to be significantly superior. Postoperative infection rates were 9.4 % and 18.7 % (p = 0.000) respectively in Group 1 a and b, 12.0 % and 25.6 % (p = 0.008) respectively in Group 2 a and b, and 19.9 % and 29.0 % (p = 0.009) respectively in Group 3 a and b. CONCLUSION: Preoperative administration of metronidazole in addition to an effective beta-lactam antibiotic is strongly advised in elective colonic surgery, as absence of antibiotic cover against anaerobic colonic flora leads to a significantly higher postoperative infection rate.

[Surgical techniques in hepatic resections: Ultrasonic aspirator versus Jet-Cutter. A prospective randomized clinical trial]. / Wasserstrahldissektion bei Leberresektion: Ultraschallaspirator versus Jet-Cutter - Eine prospektiv randomisierte Studie -

AIM OF THE STUDY: For all resection-techniques of liver tissue intra- and post-operative blood-loss remains an important problem. Two novel resection-techniques the ultrasound-aspirator (CUSA) and the water-jet dissector (Jet-Cutter) appear to offer significant advantages regarding this problem. Aim of the present prospective clinical study was the comparison of these dissection techniques. MATERIAL AND METHODS: Prospective randomized study with the end points blood-loss, length of surgery, tissue trauma and long-term survival. FINDINGS: Significant differences between both procedures with Jet-Cutter (n = 31) versus ultrasonic surgical aspirator CUSA (n = 30) were observed regarding length of resection and complete liver ischemia time (Pringle-time). Here significant advantages of the jet-cutter-technique were observed with 28 +/- 11 minutes length of resection versus 46 +/- 19 minutes and 29 +/- 12 minutes Pringle-time versus 39 +/- 16 minutes. Furthermore, significant fewer blood transfusions were required following jet-cutter-resection with a mean of 1.5 blood units vs. 2.5 blood units using the CUSA. No differences were observed regarding postoperative long-term survival. CONCLUSIONS: The jet-cutter-technique is a fast and safe surgical procedure for liver resections and offers an attractive therapeutic alternative for various indications in liver surgery.

Prognostic factors and long-term results after surgery for gallbladder carcinoma: a retrospective study of 127 patients.

BACKGROUND: The surgical management of gallbladder cancer is controversial, especially as to the indications for reoperation, extended resection, and aggressive treatment in advanced tumor stages. METHODS: Records and follow-ups of 127 patients with gallbladder carcinoma who underwent surgery between 1980 and 1997 were examined according to the pTNM and Nevin staging systems. Factors predictive for survival were obtained from histopathologic staging and surgical procedures. RESULTS: Surgery for gallbladder cancer was associated with an overall 5-year survival rate of 6.6%. Curative resection was possible in 35.5% of cases, which resulted in 5-year survival rates of 20%. Noncurative surgery revealed poor prognosis, with median survival time limited to 3.2 months, independently of macroscopic or microscopic tumor residues. None of the latter patients survived longer than 24 months. Surgery of stage I/II cancer showed a 5-year survival rate of 64.5%. In stage III/IV tumors, resectability was only 20.4%. However, curative surgery in advanced stages significantly increased median survival from 3.2 to 19.4 months. CONCLUSIONS: Only complete tumor resection can provide long-term survival, even in advanced stages. Because negative surgical margins and UICC stage are the strongest predictors for survival, reoperation is required with all incidental findings above the T1b stage.

[Dissection techniques in liver surgery]. / Dissektionstechniken in der Leberchirurgie.

The first liver resection was performed in 1888. Since then a wide variety of dissection techniques have been introduced. The blunt dissection was replaced by novel methods, i.e. the CUSA technique and the Jet Cutter for major liver resections. These methods represent selective dissection techniques; whereas non-selective methods include the scalpel, scissors, linear stapling cutter, high-frequency coagulation, and the laser technique. The aim of this review article is the comparison of the different resection techniques in liver surgery, focussing on blood loss and resection time.

Hepatitis C virus-specific CD4+ T cell response after liver transplantation occurs early, is multispecific, compartmentalizes to the liver, and does not correlate with recurrent disease.

The role of hepatitis C virus (HCV)-specific CD4+ T cells in recurrent HCV infection after orthotopic liver transplantation (OLTx) is unclear. In parallel, 73 intrahepatic and 73 blood-derived T cell lines were established from 34 patients. At a single cell level, virus-specific interferon (IFN)-gamma production to various HCV proteins was determined by ELISPOT assay: 45 (62%) of 73 liver- or blood-derived T cell lines produced IFN-gamma in response to one of the HCV antigens. HCV specificity was detected mainly in the liver (47% vs. 23% in the blood; P<.05, chi(2) test) and was detectable earlier (< or =6 months) significantly more often than later (>6 months) after OLTx (78% vs 49%; P<.05, chi(2) test). Histology, histologic activity index, liver enzymes, and virus load did not correlate with the occurrence of HCV-specific CD4+ T cells. Despite strong immunosuppressive treatment, OLTx recipients can develop an early, multispecific, preferentially intrahepatic CD4+ T cell response that decreases over time, making it a potential candidate target for novel therapeutic approaches in the transplant setting.

Resection of a branchiomeric paraganglioma at a rare extrapulmonary location.

Thoracic paragangliomas are a rare cause of hypertension. We report the occurrence of a sporadic benign norepinephrine-producing branchiomeric paraganglioma in a 32-year-old man with paroxysms of hypertension. After localization by iodine 123-metaiodobenzyl-guanidine scintigraphy and magnetic resonance imaging, the paraganglioma was resected successfully below the right pulmonary artery through a right-sided posterolateral thoracotomy. The particular location was consistent with a branchiomeric paraganglioma in an extremely rare extrapulmonary location.

[Allogenic liver transplantation: a form of "gene therapy" in metabolic diseases. Munich results and a review]. / Die allogene Lebertransplantation--eine Form der "Gentherapie" bei metabolischen Erkrankungen. Münchener Ergebnisse und Ubersicht.

INTRODUCTION: Liver transplantation is the method of choice for metabolic diseases and end-stage liver failure. METHODS: At the Klinikum Grosshadern we have performed liver transplantation for inborn errors of metabolism in 24 patients (5.3% of all transplantations, 16 adults, age 39 +/- 13 years; 8 children, age 9 +/- 3 years); 19 patients received a transplant for end-stage liver disease, and in 5 cases because of fulminant hepatic failure. RESULTS: Twenty-four patients received 27 transplants. In 3 cases, a split-liver transplantation was performed; one patient received a combined lung-liver graft. The 5-year survival rate for children is 100% and for adults 68%. CONCLUSIONS: Liver transplantation for inborn errors of metabolism not only replaces the diseased organ, but also leads to complete reversal of the metabolic defect.

Perioperative infection prophylaxis and risk factor impact in colon surgery.

BACKGROUND: A prospective observational study was undertaken in 2, 481 patients undergoing elective colon resection in 114 German centers to identify optimal drug and dosing modalities and risk factors for postoperative infection. METHODS: Patients were pair matched using six risk factors and divided into 672 pairs (ceftriaxone vs. other cephalosporins, group A) and 400 pairs (ceftriaxone vs. penicillins, group B). End points were local and systemic postoperative infection and cost effectiveness. RESULTS: Local infection rates were 6.0 versus 6.5% (group A) and 4.0 versus 10.5% (group B); systemic infection rates in groups A and B were 4.9 versus 6.3% and 3.3 versus 10.5%, respectively. Ceftriaxone was more effective than penicillins overall (6.8 vs. 17.8%, p < 0.001). Length of postoperative hospital stay was 16.2 versus 16.9 days (group A) and 15.8 versus 17.6 days (group B). Of the six risk factors, age and concomitant disease were significant for systemic infection, and blood loss, rectum resection and immunosuppressive therapy were significant for local infection. Penicillin was a risk factor compared to ceftriaxone (p < 0.0001). Ceftriaxone saved 160.7 EUR versus other cephalosporins and 416.2 EUR versus penicillins. CONCLUSION: Clinical and microbiological efficacy are responsible for the cost effectiveness of ceftriaxone for perioperative prophylaxis in colorectal surgery.

The femoral hernia: an ideal approach for the transabdominal preperitoneal technique (TAPP).

BACKGROUND: We designed a study to determine the rate of intra- and postoperative complications as well as the rate of recurrences in elective operated femoral hernias treated via the laparoscopic technique. METHODS: Between 1993 and 1998, we performed 1,097 operations in our department using the laparoscopic transabdominal preperitoneal (TAPP) technique. Femoral hernias amounted to only 4.6% (51 cases) of these patients. The male/female ratio was 1:2. The data concerning the operations and pre- and postoperative treatment were recorded prospectively. The patients were followed up at 2 weeks and 1 year after the operation. RESULTS: We encountered one intraoperative bladder lesion, one subcutaneous port site infection, two postoperative hematomas that required reoperation, and two nerve irritation syndromes, which disappeared spontaneously after 6 months. Two patients developed an ileus; one required laparoscopic reintervention, and the other was treated with conventional open reoperation and intestinal resection. There were no recurrences. CONCLUSIONS: The application of the laparoscopic approach to the treatment of femoral hernias using the TAPP technique in nonemergency situations is highly effective. To date, we have seen no recurrences. Although the rate of major complications is low, current surgical techniques need to be perfected to avoid the type of complication recognized in this study.

Impact of virtual reality imaging on hepatic liver tumor resection: calculation of risk.

The risk involved in partial liver resections depends mainly on tumor localization, invasion of central vascular structures, and parenchymal function. The imaging techniques available today (computed tomography, magnetic resonance imaging) allow us to detect precisely the extent of tumor invasion and their relationship to central vessels. The various three-dimensional reconstruction techniques are helpful with regard to a virtual planning of liver resections. The calculation of remaining liver volumes subsequent to partial hepatectomies are considered to be an essential predictive parameter in terms for the development of postoperative liver failure. In a retrospective and a later consecutive, prospective clinical study we analyzed the postoperative risk in a series of 570 patients. In an univariate analysis 13 of 31 parameters showed significant values. In multivariate analysis only three parameters (partial hepatic resection rate, PHRR), gamma-glutamyltranspeptidase, and prothrombin activity) were independent parameters for predicting liver failure, generating the most significant values for the PHRR. In our experience the most comfortable and precise technique for evaluating PHRR is the b-spline technique.