Lebermetastasen kolorektaler Karzinome - Neoadjuvante Konzepte zum präoperativen Downstaging

Liver resection for colorectal metastases disease can be performed with curative intent at low morbidity and mortality. Only 15-30 % of liver metastases are amenable to potentially curative resection. Five year survival following primary and repeat liver resection has consistently been reported as 25-40 %. Future strategies focus at widening the indication and extending therapeutic options. The aim of neoadjuvant treatment of irresectable liver metastasis is the conversion to secondary resectability either via increasing residual liver mass (portal vein embolisation/2-stage resection) and/or reducing tumor load via chemotherapy ("down-sizing"). Current data suggest resectability following neoadjuvant chemotherapy in around 8 % of cases but varying between 1-33 %.

Evaluation of Type 1 Diabetics for Simultaneous Pancreas-Kidney Transplantation With Regard to Cardiovascular Risk

The main cause of death for diabetic patients and patients on dialysis is coronary artery disease (CAD). The most common cause of graft loss following simultaneous pancreas and kidney transplantation (SPK) is death with a functioning graft due to CAD. Therefore, careful pretransplantation evaluation of CAD is mandatory. In our series, every patient undergoes a noninvasive cardiac function test like dobutamine stress echocardiography (DSE) or myocardial thallium scintigraphy using adenosine to induce medical stress. Thirty patients were evaluated for SPK: 15 patients with myocardial scintigraphy and 8 with DSE. Seven investigations showed pathological findings and we performed coronary angiograms, none of which showed coronary artery stenosis. Seven primary coronary angiograms were performed: four due to a history of CAD and three as a primary diagnostic. Following SPK one patient died at 21 days after transplantation due to myocardial infarction. He had a history of CAD with angioplasty and stent implantation. Noninvasive cardiac function tests like DSE or myocardial scintigraphy are reliable methods to evaluate CAD in patients with diabetic nephropathy awaiting SPK. In case of a suspicious finding or a history of CAD, a coronary angiogram should be performed to assess the need for revascularization. Following this algorithm we may further reduce the mortality of SPK.

Telerobotic-assisted laparoscopic spleen-preserving partial resection of the pancreatic tail for insulinoma

Laparoscopic pancreatic resection is rarely described. Telerobotic-assisted laparoscopy may offer some advantages for resection of the pancreatic tail. A 49-year-old woman was diagnosed with insulinoma located in the pancreatic tail. Telerobotic-assisted laparoscopic spleen-preserving resection of the pancreatic tail was performed. Operation time was 195 minutes. The postoperative course was uneventful. The previously described advantages of a telerobotic approach with extended range of motion and three-dimensional view make more complex operations like pancreatic resection possible and may offer extended indications for laparoscopic surgery.

Influence of methicillin-resistant Staphylococcus aureus carrier status in liver transplant recipients

The prevalence of methicillin-resistant Staphylococus aureus (MRSA) has increased worldwide and MRSA has emerged as an important cause of sepsis in cirrhotic patients and liver transplant recipients. In this retrospective study, the prevalence of MRSA colonization and its influence on infections following orthotopic liver transplantation (OLT) was investigated. From August, 2002 until November, 2004, 66 primary cadaver OLT were performed for adult recipients. Antibody induction used Daclizumab (n = 49) or ATG (n = 14). Maintenance immunosuppression consisted of tacrolimus and steroids, with 30 patients receiving mycophenolate mofetil and 4, rapamune. For perioperative anti-infectious prophylaxis cefotaxime, metronidazole, and tobramycin were administered for 48 hours. The preoperatively performed routine swabs revealed MRSA colonization in 12 of 66 (18.2%) patients. The stage of cirrhosis was equivalent for MRSA(-) patients according to Child score. The mean MELD score was significantly higher for MRSA(+) patients (24.3 versus 18.7, P = .036). More MRSA(+) patients were hospitalized at the time of transplantation (14/54 versus 8/12, P = .018). The incidence of posttransplant infections was not significantly different among the two groups. Within the first year 7 of 66 (10.6%) patients died: 3 of 12 (25%) MRSA(+) and 4 of 54 (7.4%) MRSA(-). The 1-year survival was lower in the MRSA(+) group (74.1% versus 94.1%). In conclusion, this study did not show that an MRSA-positive carrier status implies an increased risk for septic complications following OLT. Mortality was increased for MRSA(+), but failed to show a significant difference. A significantly higher MELD score and pretransplant hospitalization for MRSA(+) patients may contribute to the higher mortality and reflect sicker patients.

Predicting creatinine clearance by a simple formula following live-donor kidney transplantation

The outcome after live-donor kidney transplantation is influenced by many parameters. The aim of our study was to establish a multivariate prognostic model for calculating the recipient's creatinine clearance after transplantation. Basic immunological, donor-, recipient- and process-related variables were assessed in a series of 18 live-donor kidney transplant patients with an uncomplicated postoperative course. Multivariate analysis was carried out with automated forward and backward selection. The following four parameters were included in the predictive model: recipient age, recipient BMI, graft clearance and degree of relationship. The coefficient of determination (R(2)) was 0.67. It could be shown that a significant prediction of creatinine clearance after living related kidney transplantation can be made, based on simple variables. Therefore, this formula could help to detect early complications in the post-transplantation course if the recipient's creatinine clearance drops below the predicted result.

[Model construction for reperfusion of the isolated pig liver]

In recent years thermal ablation of liver tumors as a minimally invasive method became a promising alternative to conventional strategies such as chemotherapy or resection of liver tissue. Thereby an electrode is placed inside the tumor delivering energy in the form of high frequency current into the target volume to achieve and maintain a tissue temperature between 60 and 100 degrees C. Cells exposed to this thermic stress undergo coagulation necrosis and are irreversibly damaged. To protect vital liver structures from heat, it is necessary to develop an online temperature monitoring system. An experimental setup perfusing isolated pig livers under physiological conditions with 0.9% NaCl solution was established to develop and evaluate the measuring technique.

Simultaneous pancreas-kidney transplantation in patients with antiphospholipid syndrome

BACKGROUND

Graft thrombosis is one of the main reasons of graft loss following simultaneous pancreas-kidney transplantation (SPK). Although antiphospholipid syndrome (APLS) is known as a high risk for graft thrombosis in kidney transplants alone, little is known about APLS in SPK.

METHODS

Between September 2000 and December 2001, 45 SPK were performed. The treatment and clinical course of 2 patients with APLS is presented.

RESULTS

In one patient, APLS was known before transplantation. After SPK, she was treated by systemic heparin followed by coumarin. Both grafts are doing well 5 months posttransplant. The second patient underwent SPK without knowledge of APLS. The patient developed a deep vein thrombosis 5 weeks posttransplant. Hypercoagulability screening revealed APLS. Treatment consisted of systemic anticoagulation. Grafts were not affected.

CONCLUSION

SPK can successfully be performed in APLS patients if anticoagulation is performed consistently. To reduce the risk of graft thrombosis, a pretransplant screening for APLS would probably be of benefit.

Sequential (domino) transplantation of the liver in a transthyretin-50 familial amyloid polyneuropathy. Special reference to cardiological diagnosis and complications

BACKGROUND

General shortage of cadaveric organs has led to a search for alternative methods to expand the donor pool. Sequential (domino) transplantation is yet another attempt to compensate for the declining consent to organ donation.

PATIENTS AND METHODS

To qualify for a domino liver transplantation, the following preconditions must be fulfilled: (1) extrahepatic disease must exist, (2) liver must be fully functional, and (3) the genetic defect in the host should recur within a sufficient latency period. Familial amyloid polyneuropathy (FAP) is an autosomal dominant disease which involves a genetic defect for transthyretin (TTR), which is predominantly produced in the liver.

RESULTS

In this report, we describe a rare case of a FAP TTR-50 variant undergoing domino liver transplantation. Since myocardial symptoms precede peripheral polyneuropathy, special emphasis should be placed on arrhythmias and the restrictive cardiomyopathy necessitating a veno-venous bypass or a cardiac pacemaker in order to improve cardiac contractility. The type of anastomosis of the suprahepatic inferior vena cava and possible alternatives are discussed.

CONCLUSION

Despite ethical problems, the advantages of the domino procedure are obvious: (1) expansion of the donor pool, (2) ability to use living donors, and (3) presence of very short ischemic time and thus excellent liver function. Due to the kinetics of TTR production and deposition, donors and recipients of FAP livers should be followed up using an extensive neurological and cardiological protocol.

Development of a computer based training program for liver transplantation

The existence and future of every scientific area is directly and indirectly dependent on advanced education in that area and the quality of the work performed. Our aim in developing this program was to improve advanced education in liver transplant surgery and to ensure the quality of the work performed by every surgeon operating in this field. We developed a module that contains extensive information on the pathogenesis, symptoms, diagnosis, X-rays and treatment plans as well as operation-videos and case studies on the most common aspects in liver transplantation. This "teachware" is now on CD-ROM and can be installed on every personal computer without special computer knowledge. The expansion and updating of the material is technically facilitated with the help of an authoring tool.

Assessment of hepatic perfusion in pigs by pharmacokinetic analysis of dynamic MR images

The purpose of this study was to evaluate a new method based on magnetic resonance imaging for the characterization of hepatic perfusion. In nine pigs dynamic MRI was performed before and after partial occlusion of the portal vein. The pharmacokinetic analysis of the contrast enhancement resulted in a set of parameters (amplitude, A; perfusion rate, kp; elimination rate, kappa(e1); lag time, t(lag)) of which kp was expected to correlate with hepatic perfusion. Reference measurements were done with ultrasound flow-meters and with a thermal diffusion probe (TDP). MR perfusion rate kp significantly dropped under partial portal vein occlusion from an average of 11.3 to 4.9 min(-1) (P < 0.001), while the difference in amplitude A was not significant. The correlation between kp and the TDP measurement was r = 0.89 (P < 0.001). Pharmacokinetic analysis of MRI contrast enhancement provides a non-invasive assessment of hepatic perfusion.

[Experimental evaluation of dynamic MRI for quantifying liver perfusion]

Gadolinium-DTPA enhanced dynamic MR imaging is a new method for the quantification of portal bloodflow and liver perfusion. In this study we evaluated the validity of this method comparing it with thermodiffusion and dopplerflowmetry in pigs. We found a significant correlation of tissue perfusion between dMRI and thermodiffusion and of portal bloodflow between dMRI and dopplerflowmetry. Partial occlusion of the portal vene was accurately detected by dMRI. Dynamic MRI could become a valuable diagnostic method for the quantification of liver perfusion.

[Disorders of hepatic microcirculation as early manifestation of rejection in clinical liver transplantation]

By means of thermodiffusion, monitoring of hepatic microcirculation was performed in 43 patients during the first week after liver transplantation. A significant decrease of liver perfusion was registered in 15 patients with early rejection. The disturbance of hepatic microcirculation preceded the increase of transaminases by 36 hours and the subsequent biopsy by 60 hours. Already 12 hours after the beginning of corticoid therapy liver perfusion started to recover. The quantification of hepatic microcirculation may facilitate faster diagnosis and treatment of early rejection following liver transplantation.