[Routine subclavian revascularisation employing regional anaesthesia]. / Routinemäßige Subclavia-Revaskularisation in Regionalanästhesie.

INTRODUCTION: The increasing incidence of endovascular surgery on the thoracic aorta (TEVAR) is leading to an increased rate of subclavian-carotid transposition (SCT). Intentional overstenting of the left subclavian artery extends the proximal landing zone. If overstenting leads to a subclavian steal syndrome, vertebrobasilar insufficiency or if the risk of spinal ischaemia is present, SCT can safely be carried out with regional anaesthesia by means of a cervical block. MATERIALS AND METHODS: Since January 2010 regional anaesthesia was employed in 13 consecutive patients receiving an SCT in our clinic. Subclavian revascularisation was performed either as adjunct procedure for TEVAR or in patients with occlusive disease of the aortic arch. The clinical course was prospectively observed. RESULTS: In 62 % of the cases (n = 8) a transposition of the subclavian artery onto the common carotid artery was carried out. In 38 % of the cases (n = 5) an intraoperative decision was made to construct a carotid-subclavian bypass. In 30 % (n = 4) of the cases a conversion from cervical block to general anaesthesia was necessary. All reconstructions proved to be patent at follow-up. CONCLUSION: Subclavian-carotid transposition under regional anaesthesia is safe and technically feasible if occlusion of the subclavian artery by thoracic stentgraft or stenosis has occurred. The technique employing regional anaesthesia can, therefore, also be offered to patients with increased risk for complications due to general anaesthesia.

Nutritional support after open liver resection: a systematic review.

BACKGROUND: Perioperative nutrition in patients with limited liver function after partial hepatic resection is still controversial. In particular, the significance of perioperative total enteral nutrition remains unresolved. The aim of this review is to investigate the impact of early postoperative total enteral nutrition on convalescence after partial liver resection. MATERIALS AND METHODS: In an internet-based Medline-Search (time course: 1960-08/2005) a total of five prospective, randomized controlled trials were found comparing the impact of enteral and parenteral nutrition after liver resection. After study validity had been established, a systematic review was undertaken (odds ratio, 95% confidence interval, p < 0.05 level of significance; Review Manager 4.2, The Cochrane Collaboration). Primary endpoints were complication rate (infection, organ malfunction) and mortality. Standardized immune parameters were also surveyed. RESULTS: Statistical analysis showed that enteral nutrition resulted in a significantly lower rate (p = 0.04) of wound infection and catheter-related complications than parenteral nutrition did. No statistically significant differences in mortality due to enteral or parenteral nutrition could be found. Patients receiving enteral nutrition showed better postoperative immune competence. CONCLUSION: Early enteral nutrition after liver resection is a safe procedure. Compared to parenteral nutrition it is associated with a decreased incidence of postoperative complications. Facing the inhomogeneity of these trials, especially in nutrition protocols and end points, this first systematic review stresses the need for an update of the importance of early enteral nutrition after liver resection within randomized controlled multicenter trials.

Transoesophageal echocardiography shows high risk of gas embolism during laparoscopic hepatic resection under carbon dioxide pneumoperitoneum.

BACKGROUND: The ultrasonically activated scalpel (UAS) enables safe and effective laparoscopic tissue dissection, making hepatic resection feasible. This study compared blood loss and risk of gas embolism using the UAS during open hepatic resection and laparoscopic hepatic resection. METHODS: Female pigs were divided into two groups for laparoscopic (n = 7) and open (n = 5) left hepatic lobectomy. The UAS was used for both tissue cutting and coagulation. Laparoscopic liver resection was performed under carbon dioxide pneumoperitoneum (intraperitoneal pressure 12 mmHg). During surgery animals were monitored haemodynamically by an arterial line and Swan-Ganz catheter. Two-dimensional transoesophageal echocardiography (2D-TEE) was used to detect gas emboli with special attention to the right atrium and ventricle. Gas emboli were graded according to size, and correlated with haemodynamic and blood gas data. RESULTS: During open and laparoscopic hepatic resection the UAS resulted in minimal blood loss and effective tissue dissection. No air embolism was seen during open surgery. With laparoscopic hepatic resection 2D-TEE revealed gas embolism in all animals. Gas embolism was accompanied by cardiac arrhythmia in four of seven animals. No direct correlation was observed between embolism episodes and blood gas variables. There were no deaths after episodes of embolization. A significant decrease in arterial partial pressure of oxygen was seen at the end of the laparoscopic procedure in all animals. CONCLUSION: The UAS causes minimal blood loss during both open and laparoscopic hepatic resection. Laparoscopic liver dissection under carbon dioxide pneumoperitoneum carries a high risk of gas embolism.

Effect of fibrin glue occlusion of the hepatobiliary tract on thioacetamide-induced liver failure.

BACKGROUND: Expression and activation of hepatocyte growth factor (HGF) is stimulated by a complex system of interacting proteins, with thrombin playing an initial role in this process. The impact of temporary occlusion of the hepatobiliary tract with fibrin glue (major component thrombin) on the HGF system in acute and chronic liver damage in a rat model was investigated. METHODS: Chronic liver damage was induced in 40 rats by daily intraperitoneal application of thioacetamide (100 mg/kg) for 14 days. After 7 days half of them received an injection of 0.2 mL fibrin glue into the hepatobiliary system. Daily intraperitoneal administration of thioacetamide continued for 7 consecutive days. The rats were then sacrificed for blood and tissue analysis. Acute liver failure was induced in 12 rats by intraperitoneal administration of a lethal dose of thioacetamide (500 mg/kg per day for 3 days) after an injection with 0.2 mL fibrin glue into their hepatobiliary tract. Survival rates and histological outcome were investigated and compared with control animals. RESULTS: Fibrin glue occluded rats showed significantly lower liver enzyme activities and serum levels of bilirubin, creatinine and urea nitrogen. Immunohistochemistry revealed a significant increase in c-met-, HGFalpha- and especially HGFbeta-positive cells. Rats subjected to a lethal dose of thioacetamide survived when fibrin glue was applied 24 hours prior to the toxic challenge. These animals showed normal liver structure and no clinical abnormalities. CONCLUSION: Fibrin glue occlusion of the hepatobiliary tract induces therapeutic and prophylactic effects on chronic and acute liver failure by stimulating the HGF system. Therefore, fibrin glue occlusion might be useful in treating toxic liver failure.

Effect of insufflation gas and intraabdominal pressure on portal venous flow during pneumoperitoneum in the rat.

BACKGROUND: Carbon dioxide, the primary gas used to establish a pneumoperitoneum, causes numerous systemic effects related to cardiovascular function and acid-base balance. Therefore, the use of other gases, such as helium, has been proposed. Furthermore, the pneumoperitoneum itself, with the concomitant elevation of intraabdominal pressure, causes local and systemic effects that have been only partly elucidated. Portal blood flow, which plays an important role in hepatic function and cell-conveyed immune response, is one of the affected parameters. METHODS: An established animal model (rat) of laparoscopic surgery was extended by implanting a periportal flow probe. Hemodynamics in the portal vein were then measured by transit-time ultrasonic flowmetry during increasing intraabdominal pressure (2-12 mmHg) caused by gas insufflation (carbon dioxide vs helium). RESULTS: The installation of the pneumoperitoneum with increasing intraperitoneal pressure led to a significant linear decrease in portal venous flow for both carbon dioxide and helium. At higher pressure levels (8-12 mmHg), portal blood flow was significantly lower (1.5-2.5-fold) during carbon dioxide pneumoperitoneum. An intraabdominal pressure of 8 mmHg caused a decrease to 38.2% of the initial flow (helium, 59.7%); whereas at 12 mmHg, portal flow was decreased to 16% (helium, 40.5%). CONCLUSION: Elevated intraabdominal pressure generated by the pneumoperitoneum results in a reduction of portal venous flow. This effect is significantly stronger during carbon dioxide insufflation. Portal flow reduction may compromise hepatic function and cell-conveyed immune response during laparoscopic surgery.

Markov cohort simulation study reveals evidence for sex-based risk difference in intensive care unit patients.

BACKGROUND: Despite great advances in intensive care medicine, sepsis still is the leading cause of death. Different strategies have been developed to file the patient data into scoring systems, primarily to predict the outcome. The Markov simulation-predominantly used in economic science to describe chains of events depending on and influencing each other-seems to be an interesting and new approach in analyzing the course of disease of critically ill patients in an intensive care unit (ICU). Using such a Markov model, this study analyzes data from 660 surgical ICU patients, 44 of whom died of sepsis. METHODS: A three-state Markov model (integrating sepsis, adult respiratory distress syndrome, and mortality) was constructed to describe the course of disease of critically ill patients in defined cycles and to develop the risk profile of different groups of patients. The model enables the comparison between age- and sex-related survival rates and shows the difference in life expectancy compared with an average untreated standard population. RESULTS: Women aged up to 30 years (G1F) show the best prognosis (mortality after 19 cycles 8.3%). On the contrary, the corresponding male group (G1M) demonstrates the worst outcome (mortality after 19 cycles 57.7 %). CONCLUSIONS: The findings of this study fit into the current discussion that female patients are better positioned to meet the challenge of sepsis.

Portal venous flow during CO(2) pneumoperitoneum in the rat.

BACKGROUND: CO(2) gas insufflation is routinely used to extend the abdominal wall. The resulting pneumoperitoneum has a number of local and systemic effects on the organism. Portal blood flow, which plays an important role in hepatic function and cell-conveyed immune response, is one of the affected parameters. METHODS: An established animal model (rat) of laparoscopic surgery was modified by implanting a perivascular flow probe. Hemodynamics in the portal vein were then measured during increasing intraabdominal pressure generated by carbon dioxide insufflation. RESULTS: Using this technique, an adequate flowmetry of the portal vein was achieved in all animals. The creation of a CO(2) pneumoperitoneum with increasing intraabdominal pressure led to a linear decrease in portal venous flow. CONCLUSIONS: Elevated intraabdominal pressure caused by carbon dioxide insufflation may compromise hepatic function and cell-conveyed immune response during laparoscopic surgery.

Surgical strategies -- anastomosis or stoma, a second look -- when and why?

INTRODUCTION: The indication for performing a primary anastomosis or an intestinal stoma has to be confirmed or negated for every individual case of intestinal ischemia. DISCUSSION: In right-sided colonic emergency, primary anastomosis is possible except when associated with generalized peritonitis. In left-sided colonic ischemia and necrosis, delayed anastomosis is the preferred alternative. In ischemia following surgery for abdominal aortic aneurysms, primary anastomosis is contraindicated. In ischemia of the small bowel, an end-to-end anastomosis should be established whenever possible. CONCLUSION: In the case of intestinal ischemia, a second-look laparotomy is mandatory 24-48 h after initial surgery to ensure bowel viability. This second look should be performed regardless of the patient's postoperative clinical status. Laparoscopy has been successfully used for reexploration in intestinal ischemia, but one has to be aware of the present limitations of experience using this technique.

[Changes in portal blood flow volume by CO2 pneumoperitoneum in the rat]. / Veränderungen des portalen Blutvolumenflusses durch ein CO2-Pneumoperitoneum in der Ratte.

To measure alterations of hemodynamics in the portal vein during increasing intraabdominal pressure due to carbon dioxide insufflation an established animal model of laparoscopic surgery in the rat was extended by implantation of a perivascular flow probe. Using this technique an adequate flowmetry of the portal vein was achievable in all animals. The installation of a CO2 pneumoperitoneum with elevating intraabdominal pressure led to a linear decrease of portal venous flow. This might compromise liver function and cell-conveyed immunoresponse in the liver during laparoscopic surgery.

[Intraoperative autotransfusion and use of cell saver systems]. / Intraoperative Autotransfusion und Verwendung von Cell-Saver-Systemen.

In the last two years we have performed intraoperative autotransfusion by a cell-saving-system in 46 patients causing a 70%-reduction in the need of homologous blood transfusion. 20% of these patients did not need homologous blood at all. Besides minimizing transfusion-associated risks, intraoperative autotransfusion had an evident cost-sparing effect.