[Living donation liver transplantation in children]. / Lebendspende-Lebertransplantation beim Kind.

Liver transplantation is the first-line therapy for children with acute and chronic hepatic failure, metabolic liver diseases and liver tumors. As most of the children with end-stage liver disease are very small in stature the resources of compatible organs of deceased donors are limited. Living liver donation was able to nearly eliminate waiting list mortality with excellent patient and graft survival. As 80% of the pediatric recipients have a body weight <25 kg donation of the left lateral lobe (segments II+III) is sufficient in most of the cases. According to a standardization of the surgical procedures as well as the preoperative, intraoperative and postoperative management donation of the left lateral lobe advanced to a procedure with very low donor morbidity and mortality rates. The complexity of hepatic disease patterns in pediatric patients which often affect other organ systems demand a close cooperation with an experienced pediatric team. Pediatric living donor liver transplantation requires high expertise in liver surgery and split liver transplantation and should therefore only be performed in transplant centers meeting these high qualifications.

[Present state of radio frequency ablation of liver tumors in Germany]. / Aktueller Stand der Radiofrequenzablation von Lebertumoren. Eine deutschlandweite Umfrage.

INTRODUCTION: Radio frequency ablation (RFA) represents a new technique for local destruction of liver tumors. Indication and procedure are poorly validated at present. METHOD: To record the actual nationwide RFA application in Germany, a survey of 2026 hospitals with standardized questionnaires was conducted. RESULTS: With a respond rate of 17.5%, results from 58 hospitals covering 1700 ablated patients were analyzed. In 25.9% of them, RFA is already used in potentially curative resectable tumors, in 22.4% even when incomplete ablation for tumor mass reduction is expected. Of the 58 hospitals, 75% combine resection and RFA to reach a so-called R-0 situation. The maximal tumor sizes they quoted for achieving complete ablation ranged from <3 cm to 11 cm. In contraindications for RFA, the tumor size, number of tumors, critical localization of the tumor, and disorders of liver function were mentioned the most. CONCLUSION: This survey documents significant discrepancies in indication, application, procedure, and results in RFA for liver tumors. The lack of general standards and an overestimation of the method may lead to uncritical application, neglect of standard therapy, or unsatisfying results.

[Formation of portal venous collaterals after ligation of the portal vein for induction of liver regeneration]. / Portale Kollateralenbildung nach Pfortaderligatur zur Leberregenerations-Induktion im Schweine-Modell.

PURPOSE: Unilateral occlusion of the portal vein induces contralateral lobar hypertrophy - in contrast to complete portal vein occlusion which will result in a cavernous transformation. The impact of the formation of collaterals in partial portal vein occlusion is not sufficiently known. The lobar-hypertrophy- phenomenon is in clinical use for several years to induce iatrogenic liver growth to enable extended resections. After portal vein ligation in patients prior to extended hepatic resections, we noticed a perfusion of the formerly occluded side on CT. Using the well-established mini pig model, we were interested whether portal collaterals are formed as cause of the reperfusion. Ex-situ angiograms of the liver were used for the depiction of collaterals. MATERIALS AND METHODS: Using a median laparotomy as access for preparation of the hepatoduodenal ligament, a proximal left portal vein ligation was performed in eight mini pigs under general anesthesia. The total arrest of the portal blood flow (except in segments VI and VII) was documented by duplex ultrasound. After 4 weeks, all pigs were sacrificed and the weight of the ligated liver segments and non-ligated liver segments was measured and compared to a sham group (n = 5). After insertion of a guiding sheath, an ex-situ DSA of the portal vein was acquired. RESULTS: Compared with the sham group, the liver weight increased by 60 % (23 - 99 %, std. dev. 30 %) in segments VI and VII. Atrophy of the ligated segments was signified by a weight loss of 10 % (standard deviation 15 %). The ex-situ angiograms revealed a uniform pattern of collaterals with subsequent complete total recanalization of the formerly occluded portal vein distal from the ligation. The collaterals reduced the portal venous flow rate. CONCLUSION: After portal vein ligation, uniform collateralization results in recanalization of the occluded portal vein. The extent of the collaterals exceeds the known cavernous transformation. The increase in liver volume is not restrained by the formation of collaterals.

[Medical-surgical evaluation of living liver donors]. / Medizinisch-chirurgische Evaluation von Leber-Lebendspendern.

The living related liver segment transplantation is an established procedure in liver transplantation for children and adults. The evaluation of a possible donor should consider the following subjects: (1) Assessment of organ quality by imaging of size and anatomy of the liver and exclusion of the unknown liver diseases by labority analysis and liver biopsy. (2) Risk assessment of the potential organ donor by exclusion of preexisting diseases increasing the risk of surgery, including thromboembolic risk factors. (3) Psychological evaluation. Nevertheless the evaluation procedure should by practicable, convenient for the organ donor and cost effective. This can be realized by a stepwise program.

Split liver transplantation (SLT).

OBJECTIVES: In the last three decades liver transplantation (LT) has become a standard procedure for terminal liver failure. Anyway the procedure is highly limited by the availability of donor organs. The use of segmental liver grafts from living or cadaver donors are an attractive way to increase the donor pool for LT in adults and children. METHODS: Between 1991 and April 1999 we performed 647 liver transplantations in 416 adults and 231 children. 431 OLT, 124 SLT and 92 LRLT. Commonly used segmental liver grafts are the full right graft, the full left graft, the left lateral lobe graft and the right extended graft from living or cadaver donors respectively. RESULTS: The 1-year survival of elective SLT in adults is 80.5% and in children 84.3% (SLT + LRLT). CONCLUSIONS: Splitting procedures in liver transplantation are a promising completion to whole organ transplantations. The results of split liver (SLT) and living related liver transplantations (LRLT) are comparable to whole organ transplantations. These methods are able to increase the organ pool and thus decrease the pretransplant mortality both in children and adults.