Recent clinical experience with left heart bypass using a centrifugal pump for repair of traumatic aortic transection.
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OBJECTIVE: To analyze the indications, results, and limitations of using left atrial to femoral artery (LA-FA) bypass to provide distal perfusion during repair of traumatic aortic injuries. SUMMARY BACKGROUND DATA: There is no consensus about the best method for repair of traumatic aortic transection. Distal aortic perfusion with LA-FA bypass and a centrifugal pump has been the authors' preferred technique for injuries to the aortic isthmus and descending thoracic aorta. METHODS: From 1988 to 1998, the authors operated on 30 patients with traumatic aortic transection using LA-FA bypass. The mean age of the group was 36+/-2 years. The mechanism of injury was from a motor vehicle accident in 97% of the cases. Distal aortic perfusion was maintained at 50 to 75 mm Hg with flow rates of 1.5 and 3 L/min. The mean aortic cross-clamp time was 38+/-2 minutes, and the mean bypass time was 49+/-2 minutes. RESULTS: No complications related to cannulation, arterial thromboembolism, renal failure, mesenteric ischemia, or hepatic insufficiency occurred. There were no cases of postoperative paraplegia and no deaths. CONCLUSION: Left atrial to femoral artery bypass is a safe, simple, and effective adjunct to the repair of traumatic injuries to the thoracic aorta. Active distal aortic perfusion preserves spinal cord, mesenteric, and renal blood flow and eliminates the potential catastrophic consequence of spinal cord ischemia from an unexpectedly prolonged aortic cross-clamp time. (+info)
Helical computer assisted tomography in pulmonary hypertension complicating left-to-right shunts--correlation with pulmonary hemodynamics.
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The present study analyzed the helical computer-assisted tomography (CAT) findings in 30 patients with pulmonary hypertension (PH) associated with left-to-right shunts; specifically, ventricular septal defect, 23; atrioventricular septal defect, 6; patent ductus arteriosus, 1. Eight patients had 21 trisomy. Age ranged from 1 to 18 (mean, 4.1) months, and body weight ranged from 2.6 to 10.7 (mean, 4.9) kg. In all patients, the chest CAT revealed patchy areas of high and low attenuation (mosaic pattern) and regional atelectasis in the lung fields. The volume of low attenuated lesions and of atelectasis, and the total lung volume were derived from integration of areas measured on the CAT image. The ratios of low attenuated lesion/total lung volume (Lo), volume of atelectasis/ total lung volume (Ate) and low attenuated lesion and volume of atelectasis/total lung volume (Lo&Ate) were compared with hemodynamic parameters measured at cardiac catheterization. The pulmonary to systemic resistance ratio correlated with Lo (r=0.61, p<0.01) and Lo&Ate (r=0.69, p<0.01), whereas the pulmonary vascular resistance correlated with Ate (r=0.53, p<0.01). Lo, Ate and Lo&Ate in the chest CAT are reliable parameters that can be used to estimate pulmonary vascular resistance in patients with PH associated with left-to-right shunts. (+info)
Traumatic rupture of the thoracic aorta: cohort study and systematic review.
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PURPOSE: Through a systematic review of the literature, we identified the optimal management of traumatic ruptures of the thoracic aorta (TRTA) and reported the results of a cohort of patients treated with the clamp-and-sew technique (CAS) at a tertiary trauma center. METHODS: Studies were identified through Medline and the Cochrane library and from reference lists and papers from the authors' files. Studies with a single consistent protocol (CAS, Gott shunt [GS], left heart bypass [LHB], or partial cardiopulmonary bypass [PCPB]) that reported mortality and neurologic outcomes were included. Relevance, validity, and data extraction were performed in duplicate. A retrospective review of charts from June 1992 to August 2000 provided the database for our experience. RESULTS: Twenty studies reporting on 618 patients were found to be relevant. Interobserver agreement for relevance and validity decisions was high. Mortality rates for repair with CAS, GS, LHB, and PCPB were 15%, 8%, 17%, and 10%, respectively, and for paraplegia they were 7%, 4%, 0%, and 2%, respectively. The difference in mortality rates was not statistically significant. CAS had a higher incidence of neurologic deficits than GS (odds ratio [OR], 1.8; 95% CI, 0.4-8), LHB (OR, 6.4; 95% CI, 0.8-50), and PCPB (OR, 3.4; 95% CI, 1-10). In our cohort of 25 patients, 21 underwent surgery with CAS. The median abbreviated injury severity score was 20 (range, 4-50). The mean aortic clamp time was 30 +/- 12 minutes. Aortic repair was achieved with graft interposition in 43% of patients, and simple suture was achieved in 57% of patients. Mortality (10%) and neurologic complication (paraplegia, 11%; paraparesis, 5%) rates were not statistically different from those reported in the literature. CONCLUSION: CAS is associated with a similar mortality rate but a higher incidence of neurologic deficits than methods with distal aortic perfusion. (+info)
Visceral and renal tissue oxygenation during supraceliac aortic crossclamping and left heart bypass with selective organ perfusion.
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INTRODUCTION: Left-heart bypass (LHB) and selective organ perfusion (SOP) are used during thoracoabdominal aortic surgery to prevent ischemic damage to the kidneys and visceral organs after supraceliac aortic crossclamping. We studied the hypothesis, in a porcine model, that despite LHB and maximal SOP, visceral and renal ischemia still occurred during surgery. MATERIAL AND METHODS: Eleven pigs (54-70 kg) were coupled to a non-pulsatile LHB with inflow and outflow at the lower thoracic and distal infrarenal aorta, respectively. After supracoeliac and infrarenal aortic crossclamping, SOP was started using perfusion catheters. The proximal and distal mean aortic blood pressures were kept above 70 and 50 mmHg, respectively, while the mean blood pressure within the SOP system was above 60 mmHg. The visceral and renal tissue oxygenation was measured by intermittent blood gas analysis, from the portal and both renal veins. The jejunal mucosal oxygenation was measured by tonometric measurement of the luminal pCO2. RESULTS: Measured median blood blood flow through the LHB and the SOP system were 800 and 1140 ml/min, respectively. Median blood flow prior to, and during LHB and SOP through the celiac artery, superior mesenteric artery, and left renal artery were 300 and 240, 762 and 295, and 235 and 235 ml/min, respectively. During 3 h of LHB and SOP no significant changes in the renal tissue oxygenation were noted compared with the physiological situation prior to supracoeliac aortic crossclamping and cannulation. However, in the visceral vascular bed median mixed venous oxygen saturation dropped from 79 to 63% (p<0.001), and median oxygen extraction ratio increased from 26 to 41% (p<0.001). Median tonometric measured intraluminal jejunal pCO2 increased from 9.9 to 12.15 kPa (p>0.05). During 3 h of LHB and SOP no hemolysis was detected, as there was no rise in serum LDH. CONCLUSION: LHB and SOP preserves renal but not visceral tissue oxygenation during supraceliac aortic crossclamping and does not induce hemolysis. (+info)
Repair of the torn descending thoracic aorta using the centrifugal pump for partial left heart bypass.
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OBJECTIVE: To describe the relevant anatomy and sequential technical maneuvers to repair blunt injuries to the descending thoracic aorta with partial left heart bypass. SUMMARY BACKGROUND DATA: Blunt injury to the descending thoracic aorta remains among the most lethal and morbid of anatomic injuries. Of the techniques of repair which have evolved, "clamp and sew" is simple but has an unacceptable risk of paraplegia. In contrast, partial left heart bypass is more complex but virtually eliminates the risk of paraplegia. METHOD: We present a detailed management plan for treating blunt injury to the descending thoracic aorta using partial left heart bypass that has evolved over the past 25 years. Preoperative Aza-blockade to reduce the risk of rupture and use of the centrifugal pump to reduce the incidence of paraplegia without the risk of systemic anticoagulation are essential. RESULTS: We present a detailed description of our management of injuries to the descending thoracic aorta. In our experience, no episodes of postoperative paraplegia have occurred with the use of this technique. CONCLUSION: Blunt injury to the descending thoracic aorta can be safely repaired using partial left heart bypass. (+info)
Clinical prospective study of biochemical markers and evoked potentials for identifying adverse neurological outcome after thoracic and thoracoabdominal aortic aneurysm surgery.
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BACKGROUND: Neurological deficit after repair of a thoracic or thoracoabdominal aortic aneurysm (TAA/TAAA) remains a devastating complication. The aim of our study was to investigate the clinical value of biochemical markers [S-100B, neurone-specific enolase (NSE) and lactate dehydrogenase (LD)], evoked potentials and their combinations for identifying adverse neurological outcome after TAA/TAAA surgery. METHODS: From 69 patients, cerebrospinal fluid and blood samples for biochemical analysis were drawn after the induction of anaesthesia, during the cross-clamp period, 5 min, 2, 4, 6, 8, and 19 h, respectively, after reperfusion. In addition, continuous perioperative recording of motor-evoked potentials after transcranial electrical stimulation (tcMEP) and somatosensory-evoked potentials was carried out. Furthermore, neurological examinations were performed. RESULTS: In patients with a defined decrease in lower extremity tcMEP during the cross-clamp period, we found that combinations of the serum concentrations of S-100B and tcMEP ratios at 4, 6, and 8 h after reperfusion had a positive and negative predictive value of 100% in predicting adverse neurological outcome after TAA/TAAA surgery. Furthermore, combinations of the serum concentrations of S-100B and NSE or LD at 19 h after reperfusion had both a positive and negative predictive value of 100% in identifying patients with adverse outcome after TAA/TAAA repair. CONCLUSIONS: TcMEP monitoring during TAA/TAAA surgery seems to be an effective but not completely sufficient guide in our protective multi-modality strategy. Combinations of the serum concentrations of S-100B and tcMEP ratios during the early reperfusion period might be associated with adverse neurological complications. Furthermore, biochemical markers could detect central nervous system injury on the first postoperative day and may have prognostic value. (+info)
Randomized comparison of cold blood and cold crystalloid renal perfusion for renal protection during thoracoabdominal aortic aneurysm repair.
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