Stefan Saad

Successful transplantation of porcine livers after warm ischemic insult in situ and cold preservation including postconditioning with gaseous oxygen.

BACKGROUND In order to reduce the shortage of viable donor livers for organ transplantation, a method has been developed that allows even predamaged livers from nonheartbeating donors to be used as transplantable organs. METHODS Porcine livers were harvested 45 min after cardiac arrest of the nonheparinized donor, preflushed with heparinized saline solution, and subsequently rinsed with University of Wisconsin solution, to which superoxide dismutase was added as an oxygen free radical scavenger. Thereafter, the livers were persufflated with gaseous oxygen via the venous vascular system while immersed in University of Wisconsin solution at 4 degrees C for 4 to 5 hr. RESULTS After orthotopic transplantation, all of the livers conditioned with gaseous oxygen were able to support life-sustaining function during the whole observation period of 7 days post transplantation, while no survival of the recipients could be obtained without the described treatment. CONCLUSIONS The present study establishes a new perspective for the use of ischemically altered livers from nonheartbeating donors for organ transplantation under clinical circumstances.

Protective effect of heat shock pretreatment with heat shock protein induction before hepatic warm ischemic injury caused by Pringle's maneuver

BACKGROUND Induction of heat shock proteins is thought to have a > cytoprotective effect against environmental stress and to result in a better ischemic tolerance. The protective ability of heat exposure and heat shock protein 72 (HSP 72) induction before warm ischemia caused by Pringles maneuver was evaluated in rats. METHODS Heat exposed rats (HS) were compared with control animals (C). The gene expression (messenger RNA) of HSP 72 and HSP 72 were detected by Northern and Western blot analyses. During 40 minutes of in situ reperfusion, liver energy metabolism and levels of standard liver enzymes were evaluated. The survival rate was determined after postoperative day 7. RESULTS After heat exposure and recovery, messenger RNA of HSP 72 and HSP 72 can be detected strongly in HS group but not in C group. During reperfusion HS group exhibited a significantly (p < 0.01) improved energy metabolism, and the release of liver enzymes was significantly (p < 0.001) reduced compared with C group. Seven-day survival rate was 100% in HS group but at 50% was significantly impaired (p < 0.05) in C group. CONCLUSIONS Heat exposure associated with HSP induction has a significant protective effect against warm ischemic liver injury, which results in a relevant improvement of survival rate.

Preoperative high dose methylprednisolone improves patients outcome after abdominal surgery.

OBJECTIVE To assess the effect of preoperative high dose methylprednisolone on stress response and outcome. DESIGN Randomised, placebo-controlled, double-blind study. SETTING University hospital, Germany. SUBJECTS 20 patients listed for abdominal surgery of whom 10 had major intra-abdominal interventions and 10 had incisional hernias repaired. INTERVENTIONS Methylprednisolone 30 mg/kg (100 ml) was given by slow intravenous infusion 90-60 minutes before operation. The control group received the same volume of sodium chloride. MAIN OUTCOME MEASURES Speed of convalescence, degree of fatigue, amount of pain, consumption of analgesics, breathing capacity, and hospital stay, as well as humoral and cellular mediators of the stress response. RESULTS Methylprednisolone significantly improved criteria of postoperative recovery, fatigue by 47%, (day 1), convalescence by about 45% (days 1-3), and breathing capacity (FEV1) between 47% and 29% (days 5, 7) (p < 0.05, ANOVA), and led to a significant reduction of median hospital stay of 4.5 days. C-reactive protein concentration was significantly decreased (by 46% on day 3) and T-cell activation was suppressed (day 1). CONCLUSION Outcome of the patients after conventional abdominal surgery is substantially improved by preoperative high dose methylprednisolone. This effect is more pronounced in patients having major operations.

One year ago not business as usual: Wound management, infection and psychoemotional control during tertiary medical care following the 2004 Tsunami disaster in southeast Asia

IntroductionFollowing the 2004 tsunami disaster in southeast Asia severely injured tourists were repatriated via airlift to Germany. One cohort was triaged to the Cologne-Merheim Medical Center (Germany) for further medical care. We report on the tertiary medical care provided to this cohort of patients.MethodsThis study is an observational report on complex wound management, infection and psychoemotional control associated with the 2004 Tsunami disaster. The setting was an adult intensive care unit (ICU) of a level I trauma center and subjects included severely injured tsunami victims repatriated from the disaster area (19 to 68 years old; 10 females and 7 males with unknown co-morbidities).ResultsMultiple large flap lacerations (2 × 3 to 60 × 60 cm) at various body sites were characteristic. Lower extremities were mostly affected (88%), followed by upper extremities (29%), and head (18%). Two-thirds of patients presented with combined injuries to the thorax or fractures. Near-drowning involved the aspiration of immersion fluids, marine and soil debris into the respiratory tract and all patients displayed signs of pneumonitis and pneumonia upon arrival. Three patients presented with severe sinusitis. Microbiology identified a variety of common but also uncommon isolates that were often multi-resistant. Wound management included aggressive debridement together with vacuum-assisted closure in the interim between initial wound surgery and secondary closure. All patients received empiric anti-infective therapy using quinolones and clindamycin, later adapted to incoming results from microbiology and resistance patterns. This approach was effective in all but one patient who died due to severe fungal sepsis. All patients displayed severe signs of post-traumatic stress response.ConclusionIndividuals evacuated to our facility sustained traumatic injuries to head, chest, and limbs that were often contaminated with highly resistant bacteria. Transferred patients from disaster areas should be isolated until their microbial flora is identified as they may introduce new pathogens into an ICU. Successful wound management, including aggressive debridement combined with vacuum-assisted closure was effective. Initial anti-infective therapy using quinolones combined with clindamycin was a good first-line choice. Psychoemotional intervention alleviated severe post-traumatic stress response. For optimum treatment and care a multidisciplinary approach is mandatory.

Endischemic oxygen persufflation to improve viability of marginally preserved donor livers

Abstract The quality of colD‐stored donor livers slowly declines beyond approximately 12 h, although these organs may still be used for clinical transplantation. The aim of the present study was to improve the energetic status and viability of long‐term‐preserved livers by short‐term gaseous oxygen insufflation prior to implantation of the organ using a technique that has already been shown to promote aerobic energy metabolism during hypothermia. Livers from ten male Wistar rats were isolated, rinsed blooD‐free. Five livers (group 1) were stored for 48 h at 4°C in UW preservation solution, and five livers (group 2) were isolated and stored in the same manner for 47 h, and were then, during the last 60 min of the preservation period, connected to a persufflation device and gaseous oxygen was introduced into the organ via the inferior caval vein, with the liver still immersed in cold UW solution. This technique of endischemic gaseous oxygenation resulted in a significant normalization of vascular resistance upon isolated reperfusion in vitro and a reduction in hepatic efflux of alanine aminotransferase as well as glutamate dehydrogenase, which led to improved recovery of the reperfused grafts of group 2 as evidenced by an elevated energy charge potential at the end of the reperfusion period. In conclusion, the technique described seemed effective in enhancing the preoperative viability of marginal donor grafts.

Natural Orifice Specimen Extraction for Avoiding Laparotomy in Laparoscopic Left Colon Resections: A New Approach Using the McCartney Tube and the Tilt Top Anvil Technique

BACKGROUND Classical laparoscopic left colon resection requires a minilaparotomy. This wound can cause pain and morbidity. We describe our technique to avoid minilaparotomy by natural orifice specimen extraction. METHODS A four-port standard laparoscopic dissection for diverticular disease and small tumors of the left colon was performed. A silicon McCartney tube was transanally inserted into the rectum to remove the specimen and to pass the anvil of the circular stapler into the abdominal cavity. The head of the anvil was mechanically pretilted to facilitate introduction into the proximal colon. Double-stapled anastomosis was performed in the usual manner. RESULTS Eight patients with diverticular disease or small tumors were operated. There were no adverse events. Operating time ranged between 95 and 180 minutes. For malignancies, tissue margins and lymphadenectomy were oncologically adequate. Four week follow-up was uneventful. CONCLUSION The described natural orifice specimen extraction technique has the potential to avoid incision-related morbidity of the minilaparotomy in laparoscopic left colon resections.

Extension of ischemic tolerance of porcine livers by cold preservation including postconditioning with gaseous oxygen.

Background. Transplantation of organs from nonheartbeating donors was recommended to reduce organ shortage. In vitro experiments with rat livers have shown that the warm ischemic tolerance of the liver may be extended by persufflation with gaseous oxygen during cold storage. The qualification of this method for procurement of livers harvested after cardiac arrest was tested in an in vivo approach with pigs. Methods. Livers from 15 donor pigs were explanted, heparinized, flushed with and stored in University of Wisconsin solution for 4 hr at 4°C, and then implanted into 15 recipients. The organs were dissected immediately after cardiac arrest (group 1) or after 60 min of warm ischemia (groups 2 and 3). Group 2 livers received 75,000 IU of superoxide dismutase together with the flush solution and were persufflated with gaseous oxygen via the venous vascular system during cold storage. Main end point was survival after 5 days. Additionally, metabolic, functional and inflammatory criteria were measured in the blood. Results. All animals of the groups 1 and 2 survived, all animals of group 3 died within 3 hr after reperfusion. In all groups the blood parameters reflected significant damage of the livers. However, the ischemic damage was comparable in the groups 1 and 2 whereas the livers of group 3 exhibited significantly higher levels of aspartate alanine aminotransferase and lactate dehydrogenase, and a significantly elongated partial thromboplastin time 1 hr after reperfusion (P =0.016). Conclusions. Venous systemic oxygen persufflation in combination with antioxidative medication is a promising new method of resuscitating ischemically altered livers from nonheartbeating donors for successful transplantation.

The effects of allopurinol and SOD on lipid peroxidation and energy metabolism in the liver after ischemia in an aerobic/anaerobic persufflation

This study was aimed at examining the vulnerability of the liver to oxygen-free radicals upon reoxygenation after prolonged ischemia. Livers from male Wistar rats were first flushed with Ringers and Euro-Collins solutions. After ischemic storage in Krebs-Henseleit solution at 37°C for 60 min and in Euro-Collins solution at 4°C for another 60 min, they were then persufflated with either gaseous O2 or N2 for 30 min at 37°C, and rinsed again with Ringers solution. Enzyme concentrations and calcium ion activities were measured in the effluent rinsing solution after passage through the liver. Treatment with superoxide dismutase (SOD) or allopurinol resulted in a significant reduction of tissue injury, determined by the enzyme loss, calcium uptake, and lipid peroxidation upon persufflation with O2. Allopurinol also improved the tissue levels of ATP and the sum of adenine nucleotides after aerobic persufflation, whereas SOD did not. Notwithstanding, neither treatment had any effect on anoxic persufflation with N2. Thus, we conclude that the postischemic liver is susceptible to oxygen-induced free radical injury and that allopurinol and SOD promote specific antioxidative protection of the liver, with the exclusion of side effects related to substrates or perfusion modalities.

Polyethylene glycol 4000 attenuates adhesion formation in rats by suppression of peritoneal inflammation and collagen incorporation.

BACKGROUND Postoperative separation of the peritoneal surfaces is a promising approach for the prevention of adhesion formation. Instillation of polyethylene glycol 4000 (PEG) was recommended as an appropriate method. METHODS In a time-course study in rats, efficacy and mode of action of PEG was investigated. Adhesions were induced by crushing of the cecum. Sixty animals were randomly allocated to three control groups with intraperitoneal instillation of 5 mL 0.9% NaCl and to three therapy groups treated with 5 mL 20% PEG. After 3, 7, and 21 days, adhesion grade, intraperitoneal leukocytes, and collagen incorporation into the adhesion strands were evaluated. RESULTS Administration of PEG resulted in a decrease of leukocytes by 43% (days 3 and 7), a reduction of the adhesion score by 85% (day 3), 77% (day 7), and 79% (day 21), and an impairment of collagen deposition by 54% (day 7) and 44% (day 21). CONCLUSIONS Coating the peritoneal surfaces with PEG is a highly effective measure to suppress the fatal sequence of posttraumatic inflammation, formation of initial adhesions, and their subsequent organization to strong permanent adhesion strands.

Involvement of oxygen in harvesting injury of the liver: An experimental study including substrate free organ persufflation to evaluate a specific therapeutic approach

SummaryThe present study was undertaken to assess the role of oxygen free radicals relating to cell damage upon reoxygenation of the ischemically altered isolated rat liver. Livers were excised and flushed via the portal vein with Ringers solution and Euro-Collins solution, to which superoxide dismutase (SOD) was added in the experimental group. After warm ischemia at 37°C and cold storage at 4°C, the livers were reperfused via the portal vein with carbogensaturated Krebs-Henseleit solution. Other livers were subjected to a retrograde persufflation via the infrahepatic caval vein with either oxygen or nitrogen and then rinsed with Ringers solution. During reperfusion, SOD-treated livers showed markedly reduced vascular resistance, lower enzyme release and enhanced VO2 accordingly, energy charge at the end of reperfusion was significantly higher in the treated group. With reference to the tissue content of malondialdehyde, SOD-treated livers showed significantly less damage than the controls. Our experiments with substrate-free persufflation provided sound corroboration for these data. Enzyme activities in the eluate were significantly reduced under anoxic conditions as well as in the presence of SOD. We conclude from these data that oxygen free radicals do exert a detrimental impact on the reoxygenated liver, which could be specifically suppressed by application of exogenous SOD.