Per Skoog

Tissue plasminogen activator-assisted hematoma evacuation to relieve abdominal compartment syndrome after endovascular repair of ruptured abdominal aortic aneurysm.

Purpose To describe our experience with a novel technique to decompress abdominal compartment syndrome after endovascular aneurysm repair (EVAR) of ruptured abdominal aortic aneurysm (rAAA). Method From January 2003 to April 2010, 13 patients (12 men; mean age 75 years) treated for rAAA with EVAR underwent tissue plasminogen activator (tPA)–assisted decompression for intra-abdominal hypertension. All of the patients but one had intra-abdominal pressure >20 mmHg, with signs of multiple organ failure or abdominal perfusion pressure <60 mmHg. With computed tomography guidance, a drain was inserted into the retroperitoneal hematoma, and tPA solution was injected to facilitate evacuation of the coagulated hematoma and decrease the abdominal pressure. Results In the 13 patients, the mean intra-abdominal pressure decreased from 23.5 mmHg (range 12–35) to 16 mmHg (range 10–28.5). A mean 1520 mL (range 170–2900) of blood was evacuated. Urine production (mean 130 mL/h, range 50–270) increased in 7 patients at 24 hours after tPA-assisted decompression; among the 5 patients in which urine output did not increase, 3 underwent hemodialysis by the 30-day follow-up. One patient did not respond with clinical improvement and required laparotomy. The 30-day, 90-day, and 1-year mortality was 38% (5/13 patients); none of the deaths was related to the decompression technique. Conclusion tPA-assisted decompression of abdominal compartment syndrome after EVAR can decrease the intra-abdominal pressure and could be useful in preventing multiple organ failure. It is a minimally invasive technique that can be used in selected cases but does not replace laparotomy or retroperitoneal surgical procedures as the gold standard treatments.

Intra-peritoneal microdialysis and intra-abdominal pressure after endovascular repair of ruptured aortic aneurysms.

OBJECTIVES This study aims to evaluate intra-peritoneal (ip) microdialysis after endovascular aortic repair (EVAR) of ruptured abdominal aortic aneurysm (rAAA) in patients developing intra-abdominal hypertension (IAH), requiring abdominal decompression. DESIGN Prospective study. MATERIAL AND METHODS A total of 16 patients with rAAA treated with an emergency EVAR were followed up hourly for intra-abdominal pressure (IAP), urine production and ip lactate, pyruvate, glycerol and glucose by microdialysis, analysed only at the end of the study. Abdominal decompression was performed on clinical criteria, and decompressed (D) and non-decompressed (ND) patients were compared. RESULTS The ip lactate/pyruvate (l/p) ratio was higher in the D group than in the ND group during the first five postoperative hours (mean 20 vs. 12), p = 0.005 and at 1 h prior to decompression compared to the fifth hour in the ND group (24 vs. 13), p = 0.016. Glycerol levels were higher in the D group during the first postoperative hours (mean 274.6 vs. 121.7 μM), p = 0.022. The IAP was higher only at 1 h prior to decompression in the D group compared to the ND group at the fifth hour (mean 19 vs. 14 mmHg). CONCLUSIONS Ip l/p ratio and glycerol levels are elevated immediately postoperatively in patients developing IAH leading to organ failure and subsequent abdominal decompression.

No-touch technique for radiocephalic arteriovenous fistula - surgical technique and preliminary results

Purpose The radiocephalic arteriovenous fistula (RC-AVF) has significant failure rates due to occlusions and failure to mature. The size and quality of the veins are considerable limiting factors for the procedure. The aim of this pilot study was to describe the No-Touch technique (NTT) to create RC-AVF and present the results up to 1 year of follow-up. Methods Thirty-one consecutive patients who were referred for surgery for a RC-AVF were included (17 men, mean age 63 years, range 35-84) and operated by NTT where the vein and artery were dissected with a tissue cushion around it. Twenty-two patients had small veins or arteries (≤2 mm), 12 patients had a small cephalic vein (≤2 mm), and the mean distal cephalic vein diameter was 2.4 mm (range 1.0-4.1 mm). Results Technical surgical success and immediate patency were obtained in all patients. Clinical success was achieved in 23 of the 27 (85%) patients who required hemodialysis. The proportion of primary patency at 30 days and 6 months was 84% and 64%, respectively. Secondary patency at 30 days and 6 months was 97% and 83%, respectively. At 1-year follow-up, primary patency was 54% and secondary patency was 80%. There was no major difference in patency due to preoperative vein diameter. Conclusions The results of this study indicate that NTT can be used for primary radio-cephalic fistula surgery with very good results. This method offers the potential to create a RC-AVF in patients who are not usually considered appropriate for a distal arm fistula due to a small cephalic vein.

Intra-abdominal Hypertension—An Experimental Study of Early Effects on Intra-abdominal Metabolism

BACKGROUND The main aim of this experimental study was to investigate the early effects of intra-abdominal hypertension (IAH) on intra-abdominal metabolism and intestinal mucosal blood flow to evaluate whether metabolites can serve as markers for organ dysfunction during IAH. METHODS A swine model was used, and the animals were anesthetized and ventilated. Fifteen animals were subjected to IAH of 30 mm Hg for 4 hr by carbon dioxide insufflation. Seven animals served as controls. Hemodynamic data, arterial blood samples, and urine output were analyzed. Intraluminal laser Doppler flowmetry measured intestinal mucosal blood flow. Glucose, glycerol, lactate, and pyruvate concentrations and lactate-to-pyruvate (l/p) ratio were measured intraperitoneally and intramurally in the small intestine and rectum using microdialysis. RESULTS IAH lowered the abdominal perfusion pressure by 12-18 mm Hg, reduced the intestinal mucosal blood flow by 45-63%, and decreased urine output by 50-80%. In the intervention group, glycerol concentrations increased at all locations, pyruvate concentrations decreased, and the l/p ratio increased intraperitoneally and intramurally in the small intestine. Control animals remained metabolically stable. Glucose and lactate concentrations were only slightly affected or unchanged in both the groups. CONCLUSIONS IAH reduces intestinal blood flow and urinary output and causes early metabolic changes, indicating a discrete shift toward anaerobic metabolism. Intraperitoneal microdialysis may be useful in the early detection of impaired organ dysfunction with metabolic consequences in IAH and abdominal compartment syndrome.

Blood pressure targeting by partial REBOA is possible in severe hemorrhagic shock in pigs and produces less circulatory, metabolic and inflammatory sequelae than total REBOA

BACKGROUND Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an effective adjunct in exsanguinating torso hemorrhage, but causes ischemic injury to distal organs. The aim was to investigate whether blood pressure targeting by partial REBOA (pREBOA) is possible in porcine severe hemorrhagic shock and to compare pREBOA and total REBOA (tREBOA) regarding hemodynamic, metabolic and inflammatory effects. METHODS Eighteen anesthetized pigs were exposed to induced controlled hemorrhage to a systolic blood pressure (SBP) of 50 mmHg and randomized into three groups of thoracic REBOA: 30 min of pREBOA (target SBP 80-100 mmHg), tREBOA, and control. They were then resuscitated by autologous transfusion and monitored for 3 h. Hemodynamics, blood gases, mesenteric blood flow, intraperitoneal metabolites, organ damage markers, histopathology from the small bowel, and inflammatory markers were analyzed. RESULTS Severe hemorrhagic shock was induced in all groups. In pREBOA the targeted blood pressure was reached. The mesenteric blood flow was sustained in pREBOA, while it was completely obstructed in tREBOA. Arterial pH was lower, and lactate and troponin levels were significantly higher in tREBOA than in pREBOA and controls during the reperfusion period. Intraperitoneal metabolites, the cytokine response and histological analyses from the small bowel were most affected in the tREBOA compared to the pREBOA and control groups. CONCLUSION Partial REBOA allows blood pressure titration while maintaining perfusion to distal organs, and reduces the ischemic burden in a state of severe hemorrhagic shock. Partial REBOA may lower the risks of post-resuscitation metabolic and inflammatory impacts, and organ dysfunction.