Analysis of the biliostatic potential of two sealants in a standardized porcine model of liver resection

BACKGROUND

Improved resection techniques has decreased mortality rate following liver resections(LRx). Sealants are known as effective adjuncts for haemostasis after LRx. We compared biliostatic effectiveness of two sealants in a standardized porcine model of LRx.

MATERIAL AND METHODS

We accomplished left hemihepatectomy on 27 pigs. The animals were randomized in control group(n = 9) with no sealant and treatment groups (each n = 9), in which resection surfaces were covered with TachoSil^® and TissuFleece^®/Tissucol Duo^®. After 5 days the volume of ascites(ml), bilioma and/or bile leakages and degree of intra-abdominal adhesions were analysed.

RESULTS

Proportion of ascites was lower in TissuFleece/Tissucol Duo^® group. The ascites volume was lower in TachoSil^® group. In sealant groups, increased adhesion specially in the TachoSil^® group was seen. A reduction of the "bilioma rate" was seen in sealant groups, which was significantly lower in TissuFleece^®/Tissucol Duo^® group.

CONCLUSION

In a standardized condition sealants have a good biliostatic effect but with heterogeneous potentials. This property in combination with the cost-benefit analysis should be the focus of future prospective studies.

[Definition of surgical degree of freedom by functional anatomy in liver resection surgery]

Liver resections have developed to very complex and differentiated operations, clearly adapted to individual anatomical and physiological conditions. In parallel, perioperative morbidity has been dramatically reduced. Intraoperative strict consideration of various details of hepatic anatomy, particularly of functional liver anatomy, has proved to be of particular importance when liver surgery reaches indication and technical limits. The term "functional anatomy" stands for a form of hepatic substructurization, which is primarily based on the existence of hemodynamically independent regions of liver parenchyma. A selection of some of the most important details and facts of functional liver anatomy and secondary derived guidelines for surgical strategy and technique is presented in an overview, with special focus on liver resection.

Intraoperative evaluation of big-endothelin plasma levels during liver transplantation in different vascular compartments

Endothelin-1 (ET) is derived from its precursor big-ET, secreted by endothelial cells of multiple origin. The role of ET peptides in the physiological responses after orthotopic liver transplantation (OLT) was investigated. Venous big-ET plasma levels were analysed by RIA in 28 patients before and after OLT. Samples for analysis were taken intraoperatively from 12 patients from the caval, portal and hepatic veins and the radial artery at multiple time points. Highest caval levels were found during the anhepatic period and 60 min after reperfusion, followed by a drop and subsequent increase postoperatively. Highest levels in the hepatic and portal veins were detected during explanation and reperfusion. A different pattern was found in the radial artery. Values during rejection and infection were elevated compared with preoperative and postoperative levels. The heterogeneity of the kinetics points to different sites of ET generation, including liver and splanchnic circulation. It suggests a predominant paracrine secretion mode of ET peptides with various stimuli involved. Big-ET levels could reflect endothelial cell damage, as big-ET is generated intracellularly and biological activity is rather weak.

[Operational costs and control of performance in surgical clinics between marketing and planning economics. Risk or perhaps quadrature of the circle]

Surgical hospitals can be seen as operational or even industrial production systems. Doctors have a major impact on both medical performance and costs. For active participation in the management process, knowledge of industrial controlling mechanisms is required. German hospitals currently receive no procedure-related financial revenues, such as prices or tariffs for defined medical treatment activities. Maximum clinical revenues are, furthermore, limited by principles of planned economy and can be increased only slightly by greater medical performance. Costs are the only target that can be autonomously influenced by the management. Operative controlling in hospitals aims at horizontal and vertical coordination of subunits and decentralization of process regulations. Hospital medical performance is not clearly defined, its quantitative measurement very problematic. Process-orientated clinical activities are not taken into account. A high percentage of hospital costs are fixed and can be influenced only by major structural interventions in the long term. Variable costs are primarily dependent on the quantity of clinical activities, but also heavily influenced by patient structure (comorbidity and risk profile). The various forms of industrial cost calculations, such as internal budgeting, internal markets or flexible plan-cost balancing, cannot be directly applied in hospital management. Based on these analyses, current operational concepts and strategic trends are listed to describe cost-management options in hospitals with focus on the German health reforms.

Determination of plasma activities of purine nucleoside phosphorylase by high-performance liquid chromatography: estimates of nonparenchymal cell injury after porcine liver transplantation

An assay is described for measurement of purine nucleoside phosphorylase (PNP) in plasma by high-performance liquid chromatography (HPLC). A plasma sample was incubated with hypoxanthine and ribose-1-phosphate in phosphate-free medium at pH 7.4 to catalyse the production of inosine by plasmatic PNP. The reaction was stopped by addition of perchloric acid to inactivate the enzyme and to precipitate plasma proteins. After centrifugation and neutralization of the supernatant with NaOH the increase in the substrate inosine was determined by HPLC. Plasma activities of PNP averaged 5.0 mU/ml before and 12.3 mU/ml (p < 0.001), 5 min after porcine liver transplantation. At the same time points, the plasma activities of the frequently used liver enzymes lactate dehydrogenase or alanine aminotransferase remained virtually unchanged. Thus, plasmatic activities of PNP may be a suitable and early indicator of ischemic alterations to the graft in vivo.

[Developments up to now and current status of adjuvant chemo- and radiotherapy in colonic and rectal carcinoma]

A review is given of the historical and current concepts of adjuvant chemo- and radiotherapy of colorectal cancer. Early studies analyzing the use of single drug regimens were followed by a second study generation investigating adjuvant chemotherapeutic combinations. 5-FU proved to be the most efficient single drug investigated and 5-FU/MeCCNU/vincristin the most efficient chemotherapeutic combination, but no significant improvement in 5-year survival rates was achieved. Clear progress was noted with the introduction of levamisol (LEV) for modulation of 5-FU. A 33% improval in the 5-year survival rate in patients with stage III colon carcinoma was documented. It was therefore recommended (NIH consensus conference 1990) that all patients with stage III colon carcinoma be treated with this regimen unless admitted to other trials of adjuvant therapy. Preoperative radiotherapy with a dosage of 35-45 Gy can lead to downstaging of rectal cancer. Nevertheless, significant improvement in patient survival has not been proved convincingly using either isolated pre- or postoperative adjuvant radiotherapy. However, combined radiochemotherapy has been shown to improve both patient survival and local tumor control compared to surgical resection alone. It is therefore recommended that all stage II and III rectal cancer patients be treated with adjuvant combined radiochemotherapy. 5-FU/MeCCNU is currently expected to be the most efficient chemotherapy in combination with radiotherapy. Early data point out that MeCCNU could possibly be omitted. Intraoperative radiotherapy (IORT) allows further dosage escalation in order to improve local tumor control without affecting radiosensitive structures. Available data are still sparse and mostly based on the treatment of advanced carcinoma. A general validation of IORT is not yet possible, but current data are promising.

Revision of the proximal aortic anastomosis after aortic bifurcation surgery

The implantation of an aortic bifurcation graft (ABG) for treatment of occlusive (OD) and aneurysmal (AD) aortoiliac disease is a standard technique with good long-term results and a relatively low incidence of complications. In a retrospective review of our patients from 1964 to 1993 only 36/1520 patients were identified who required reoperation at the proximal aortic anastomosis after ABG. Indications were graft occlusion (15/36) and graft stenoses (2/36), refractory to graft thrombectomy, proximal aortic anastomotic aneurysms (11/36) or graft infection (8/36). Graft occlusion or stenosis most frequently led to aortic reoperation in the OD-group (53.5%), recurrent aneurysmal disease (37.5%) and graft infection (37.5%) were the dominant indications in the AD-group. Mean time interval to reoperation was shorter in cases of graft infection (35 +/- 33 months) as compared with graft stenosis (66 +/- 58 months), graft occlusion (86 +/- 49 months) or aortic anastomotic aneurysms (152 +/- 90 months). Of the reoperations, 92% were done electively, 8% as emergency procedures. The perioperative course was uneventful in 67% of patients. Overall mortality rate after elective revisional surgery was 3% but reached 66% in emergencies. Postoperative morbidity and mortality was related to preoperative morbidity and the urgency of surgery, not with the mode of aortic intervention nor indication.

The isolated posttraumatic aneurysm of the brachiocephalic artery after blunt thoracic contusion

Most supra-aortic aneurysms are localized in the extracranial carotid and subclavian artery. Aneurysms of the brachiocephalic artery (BCA) represent a rather rare finding. Chronic arteriosclerotic changes are responsible for the majority of cases. Posttraumatic BCA damage is only occasionally encountered, complete vascular dissection by perforating injuries being the dominant causative mechanism. Although isolated BCA trauma after blunt thoracic contusion is rare, brachiocephalic injury in association with aortic lesions seems to be the second most common site of vascular injury after the aorta. Cases of isolated blunt BCA trauma documented in the literature to date usually involved a complete avulsion of the artery from the aortic arch or complete rupture near the aortic origin. We present an isolated case of posttraumatic BCA aneurysm in a woman involved in a car accident who suffered blunt chest trauma with a subtotal, near circumferential vessel wall dissection of only the intima and media. Clinical features, diagnostic procedure, surgical treatment, and trauma mechanisms of postcontusional BCA lesions are described and discussed in reference to the literature.