Prognostic Risk Factors for the Development of Compartment Syndrome in Acute Lower Limb Ischemia Patients Treated With Catheter-Directed Thrombolysis.

BACKGROUND: To determine predisposing factors that may lead to the development of compartment syndrome (CS) in patients with acute lower limb ischemia (ALLI) managed with intra-arterial catheter-directed thrombolysis (CDT). METHODS: This is a retrospective study of patients admitted between 01/2002 and 12/2015 to three university hospitals in Tampere, Turku, and Oulu, Finland, with acute or acute-on-chronic lower limb ischemia (Rutherford I-IIb). Patients managed with CDT and aspiration thrombectomies (AT) as an adjunct to CDT were included in the study. Multivariable binary logistic regression models were used to detect possible risk factors for the development of CS and its impact on the limb salvage and survival. Amputation-free survival (AFS) rates of CS and non-CS patients were compared using Kaplan-Meier survival analysis. The length of hospitalization was calculated and compared between the CS and non-CS groups. RESULTS: A total of 292 CDTs with or without ATs were performed on patients with a mean age of 71 years (standard deviation 13 years), 151 (51.7%) being male. Altogether, 12/292 (4.1%) treatment-related CS cases were registered. Renal insufficiency (odds ratio [OR] 4.27, P = 0.07) was associated with an increased risk of CS. All CS cases were managed with fasciotomies. Treatment with fasciotomy was associated with a prolonged hospitalization of a median of 7 days versus the 4 days for non-CS patients, P < 0.001. During the median follow-up of 51 months (interquartile range 72 months), 152/292 (52.1%) patients died and 51/292 (17.5%) underwent major amputations. CS was not associated with an increased risk of mortality, but it was associated with a higher risk of major amputation (OR 3.87, P = 0.027). The AFS rates of patients with or without CS did not significantly differ from each other in the long term. CONCLUSIONS: CS after CDT for the treatment of ALLI is uncommon. Renal insufficiency is associated with an increased risk of CS. Fasciotomy prolongs the hospitalization. Patients with CS are exposed to an increased risk of major amputation.

PTFE bypass or thrupass for superficial femoral artery occlusion? A randomised controlled trial.

UNLABELLED: Early results of a thrupass endograft in the treatment of femoral lesions are promising. Less morbidity and better cost-effectiveness are suggested to be achieved in the treatment of chronic lower limb ischaemia with endovascular treatment compared to surgical treatment. PATIENTS AND METHODS: This randomised multicentre trial aimed to enroll a group of 60+60 patients for the treatment of 5-25-cm occlusions of superficial femoral artery (SFA) to be followed up for 3 years. Patients were treated either with endoluminal PTFE thrupass (WL Gore & Ass) or with surgical polytetrafluoroethylene (PTFE) bypass to proximal popliteal artery. Primary patency at 3 years was scheduled to be the primary end-point and secondary patency, functional success, costs and quality of life the secondary end-points. RESULTS: A sample of 100 consecutive SFA occlusions in one of the centres revealed that only 4% of the lesions were amenable for the study. The trial was prematurely terminated due to the results of an interim analysis at the time when 44 patients were recruited: the 1-year primary patency (excluding technical failures) was 48% for thrupass and 95% for bypass (p=0.02). The patency difference in favour of surgical bypass over endovascular thrupass was also sustained after completion of 1-year follow-up, the primary patencies being 46% and 84% at 1 year with grossly equilinear life-table curves thereafter (p=0.18), respectively. The corresponding secondary patencies were 63% and 100% (p=0.05) when excluding technical failures and 58% and 100% (p=0.02) according to intention-to-treat analysis. Secondary outcomes were thus not analysed. CONCLUSION: Treatment of SFA occlusions (TASC IIB and C or Imelda Ia and II) should be done by PTFE bypass rather than by PTFE thrupass, as thrupass is connected with worse early outcome. These results represent only a small category of femoral disease.

Staged endovascular stent-grafting and surgical treatment of a secondary aortoduodenal fistula.

Secondary aortoenteric fistula is a dramatic, rather infrequent late complication occurring mostly after abdominal aortic surgery. Currently, graft excision and in situ bypass is considered the treatment of choice, but it is associated with significant mortality and morbidity. Herein, we describe the case of a secondary aortoduodenal fistula treated by staged endovascular stent-grafting and surgical closure of the fistula. Forty days after stent-grafting, Tc-99m-HMPAO labelled leukocyte scanning failed to identify leukocyte infiltration of the graft and there were no clinical signs of infection. At 8-month follow up, the patient was asymptomatic.

Baseline oxygen delivery is associated with an increased risk of severe postoperative complications after elective open repair of abdominal aortic aneurysm.

AIM: Oxyhemodynamic parameters have been shown to have a relevant impact on the immediate postoperative outcome after major surgery, but it is not known their specific impact on the outcome after elective repair of abdominal aortic aneurysm (AAA). METHODS: One-hundred and forty-one patients underwent elective open repair of infrarenal AAA and hemodynamic parameters were monitored perioperatively. RESULTS: One patient (0.7%) died postoperatively, 23 (16.3%) experienced a myocardial ischemic event and 9 of them (6.4%) had a myocardial infarction. Baseline oxygen delivery was not predictive of such myocardial ischemic events. Thirty-three patients (23.4%) suffered severe postoperative complications. The median baseline oxygen delivery was 429.5 mL/min/m2 among patients who had severe postoperative complications, whereas it was 505.5 mL/min/m2 among those who did not have severe complications (p=0.03). However, this parameter did not retain its significance at multivariate analysis. When only the preoperative variables were included in the logistic regression model, the Glasgow Aneurysm Score (P=0.004, Oddsratio 1.94, 95% C.I. 1.24-3.05) was the only predictor of severe postoperative complications. The Glasgow Aneurysm Score was significantly correlated with baseline oxygen delivery (P=-0.256, P=0.003). CONCLUSIONS: Baseline oxygen delivery is associated with an increased risk of severe postoperative complications after elective open repair of AAA. The value of preoperative optimization of oxygen delivery should be evaluated in this patient population.

Apoptotic activity is increased in brain cortex infarct after hypothermic circulatory arrest in a porcine model.

OBJECTIVE: It has been shown that apoptosis contributes to neuronal cell death after ischemia, and we evaluated the degree of apoptotic activity occurring in brain cortex of pigs after hypothermic circulatory arrest (HCA). DESIGN: Thirty-one pigs underwent 75 min of HCA at 20 degrees C. Histological examination of the brain was performed, and slides of brain cortex were evaluated for apoptotic activity by the TUNEL method. RESULTS: Ten animals died during the first postoperative day and 21 survived until the seventh postoperative day. Brain cortex infarcts were found in animals that survived 7 days and these were included in this study. The median histopathological score among animals that died on the first postoperative day was 3.0 (range, 2-4), whereas it was 4.0 (range, 2-4) among survivors (p = 0.019). The apoptotic index was particularly high in the area of the infarct, whereas only a few TUNEL-stained cells were observed in noninfarcted areas. The apoptotic index was nil in all pigs that died in the first postoperative period, whereas it was 2.0 (range, 0-6) among the animals that survived until the seventh postoperative day (p < 0.0001). CONCLUSION: The apoptotic index was significantly increased in brain cortex infarcts of animals that survived 7 days after HCA, whereas only a few apoptotic cells were observed in noninfarcted areas of these animals as well as in animals that died on the first postoperative day. Further studies are required to elucidate the timing of development of brain infarction after HCA and whether neuroprotective strategies targeting the apoptotic process may mitigate brain damage.

Determinants of mortality after hypothermic circulatory arrest in a chronic porcine model.

OBJECTIVE: Beside neurological morbidity, mortality is a relevant end-point of experimental porcine model of hypothermic circulatory arrest (HCA) and this study was conducted to identify the determinants for postoperative death. METHODS: One hundred and thirty-five pigs underwent a 75-min period of HCA at 20 degrees C to evaluate the efficacy of different methods of cerebral protection. RESULTS: Survival rate at 7-day follow-up was 52%. Lower oxygen extraction, oxygen consumption/kg, and venous lactate at the end of cooling and higher oxygen delivery rates were significantly associated with better outcome. Logistic regression showed that the oxygen consumption/kg at the end of cooling was the only predictor of mortality (P=0.046). Animals with an oxygen consumption/kg rate less than 1.43 ml/min per kg at the end of cooling had a mortality rate of 28%, whereas it was 50% among animals with an oxygen consumption/kg rate higher or equal to 1.43 ml/min per kg (P=0.020). The latter had even an increased 1-day mortality rate (40% vs. 26%) (P not significant). The mortality rate after anesthesia induction with ketamine plus 100% of oxygen was 38%, 45% after anesthesia induction with ketamine plus 35% oxygen, and 53% after anesthesia with medetomidine plus 35% oxygen (P not significant). CONCLUSIONS: Parameters of oxyhemodynamics should be monitored especially from the induction of anesthesia to the end of cooling before a 75-min period of HCA. The use of medetomidine and/or 35% of oxygen at induction of anesthesia should be avoided in favor of ketamine plus 100% of oxygen.

The role of cerebral microdialysis in predicting the outcome after experimental hypothermic circulatory arrest.

OBJECTIVE: To evaluate whether and which of the cerebral microdialysis parameters are predictive of postoperative outcome after an experimental 75-min period of hypothermic circulatory arrest (HCA) in a chronic porcine model. DESIGN: Seventy-four juvenile female pigs underwent a 75-min period of HCA at 20 degrees C. A microdialysis catheter was placed into the cortex gray matter and brain extracellular concentrations of glucose, lactate, glycerol and glutamate were measured throughout the experiment by enzymatic methods using a microdialysis analyzer. Surviving animals were sacrificed on the 7th postoperative day and histopathological examination of the brain was performed. RESULTS: Brain glucose concentrations were higher in animals that survived (p = 0.017), especially from the 90-min until the 7-h interval after the start of rewarming. The blood venous concentrations of glucose were also higher among survivors, and correlated significantly with the brain glucose levels at 2-h and 4-h intervals after the start of rewarming. Higher concentrations of brain lactate, glycerol and glutamate were observed throughout the study among animals that died postoperatively. Brain glutamate and glycerol concentrations were significantly, negatively correlated with brain glucose concentrations. The lactate/glucose ratio was significantly lower among survivors during the postoperative period (p=0.014). Furthermore, brain glucose concentrations were higher and brain glycerol concentrations lower among the animals that did not develop brain infarction, but such differences did not reach statistical significance. CONCLUSION: Cerebral microdialysis is a useful tool for cerebral monitoring during experimental HCA. Low brain glucose concentrations and high brain lactate/glucose ratios after HCA are strong predictors of postoperative death. Brain glucose concentrations are negatively correlated with brain glycerol and glutamate concentrations.

Serum S-100beta protein predicts brain injury after hypothermic circulatory arrest in pigs.

OBJECTIVE: Serum S-100beta protein is suggested to be a neurobiochemical marker of brain injury after cardiac and aortic arch surgery. The aim of the present study was to investigate the predictive value of S-100beta protein with respect to histopathological analysis of the brain after a prolonged period of hypothermic circulatory arrest (HCA). METHODS: Eighteen pigs (21 to 31 kg) underwent a 75 min period of HCA at 20 degrees C. Serum concentrations of S-100beta were assayed in mixed venous blood before and 2, 4, 7 and 20 h after HCA. A semiquantitative post-mortem histopathological analysis scoring all main regions of the brain was carried out in every animal. RESULTS: All animals were stable during and after cardiopulmonary bypass (CPB) and survived at least to the first postoperative day. Ten of the 18 animals survived 7 days after surgery and were electively sacrificed. Animals with severe histopathological injury showed higher serum S-100beta protein levels at every time point after HCA. The strongest correlation between the total histopathologic score and serum S-100beta levels was found at 7 h after HCA (tau = 0.422 and p = 0.023). CONCLUSION: Serum S-100beta protein levels correlate with histopathological injury after a prolonged period of HCA in pigs. This finding supports the results of previous studies suggesting the potential accuracy of S-100beta in the prediction of brain injury after cardiac surgery.