Biomedical subjects

G Sepa

Publications and source records attributed to G Sepa.

5 recordsLinked to original sources

PubMed2002

Biochemical alterations in cerebrospinal fluid during thoracoabdominal aortic cross-clamping in dogs.

Spinal cord damage during and after thoracoabdominal aortic cross-clamping continues to be a major problem. Somatosensory and motor evoked potentials have been used to monitor spinal cord function but their value for predicting paraplegia has been controversial. The aim of this study was to measure biochemical markers in the cerebrospinal fluid (CSF) and correlate changes with spinal cord ischemia. Since neural tissue utilizes only glucose as substrate for its metabolism and energy supply, we measured changes of metabolites of anaerobe glycolysis. In a canine model in which general anesthesia was used, the thoracoabdominal aorta was cross-clamped proximally and distally for 60 min. Hemodynamic parameters, blood gases, and glucose level were monitored continuously. Blood and CSF sampling were performed at baseline, at 15, 30, and 55 min during cross-clamping, and at 5 and 15 min after aortic declamping. Levels of lactate (1.7 +/- 0.1 to 3.2 +/- 0.3 mmol/L), pCO2 (43 +/- 2 to 35 +/- 1.6 mmHg), and neuron-specific enolase (NSE) (5.17 +/- 0.5 to 13.0 +/- 3.5 mg/L) in CSF showed significant changes (p < 0.05) during clamping and reperfusion. Changes in CSF lactate and NSE levels correlate with the duration of spinal cord ischemia. These markers of ischemic metabolism appear suitable to monitor the degree of spinal cord ischemia during thoracoabdominal cross-clamping and may be useful to predict the efficacy of preventive methods.

Animals↗

PubMed2001

[Surgical considerations in type-B aortic dissection].

Inspite of remarkable progress in both diagnostic and therapeutic development in treating aortic dissections this continues to be one of the most severe vascular catastrophies complicated by high mortality. While aortic dissections Type A are to treat surgically in our days, in majority of patients with Type B dissections hypotensive treatment is the method of choice providing better chance for survival preventing effectively aneurysm formation and rupture at the site of intimal tear. However in certain cases Type B dissection produces either isthmic aneurysm formation, or with distal progression may afflict long segmental thoracic, thoracoabdominal or abdominal deterioration of the aorta and its side branches. The spinal, visceral, renal and lower limb ischemia threatens viability of these organs and hypotensive medication may enhance risk. Prompt evaluation and selection of these cases with proper surgical reconstruction help us to reduce mortality. At our department we have performed 33 thoracoabdominal endoaortectomies with meticulous reconstruction of renal and visceral orifices. The mortality rate in this subgroup of patients was 6%, meanwhile almost 70% in those, treated medically but had the severe distal branch involvement. Based on our experiences in selected patients with Type B aortic dissections we recommend this procedure in order to achieve improvement of results.

Adult↗

PubMed2000

[New method for the intraoperative biochemical monitoring of cerebrospinal fluid in surgery of thoracoabdominal aortic aneurysms].

Paraplegia remains to be one of the most dangerous complications following thoracoabdominal aortic surgery with an incidence of 0.5 to 40%. Therefore, intraoperative monitoring of spinal cord function is very important when choosing the appropriate surgical technique. Early detection of spinal cord injury continues to be a crucial problem, moreover, the currently applied electrophysiological methods appear to be inaccurate. The aim of the study was to detect prospective spinal cord injury intraoperatively by monitoring the biochemical parameters of the cerebrospinal fluid (CSF). The authors studied the reversible aerobic/anaerobic metabolic changes by monitoring CSF lactate levels, moreover S-100 protein and neuron-specific enolase (NSE) concentrations--specific for neuroglia and neuronal injury, respectively. One of the important methods to prevent paraplegia is the intraoperative CSF drainage, which may improve spinal cord perfusion. Between 1996-1998 51 patients underwent reconstructive thoracic or thoracoabdominal aortic aneurysm operation. The continuously drained CSF was collected in 10 ml fractions during the preparation, whereas during aortic cross-clamping and de-clamping 10 minute fractions were used. All CSF samples were immediately analysed intraoperatively for pH, pCO2, HCO3, potassium and lactate levels, S-100 protein and NSE were analysed by immunoluminescence. CSF lactate levels increased slightly during aortic clamping and a moderate, but non-significant increase was found in the hyperemic phase (reperfusion) in patients without spinal cord ischemia. Spinal cord injury was detected in 7 cases. These patients exhibited a significant CSF-lactate increase (control vs aortic cross-clamping: 1.9 vs 5.3 mmol/l), moreover CSF-lactate remained elevated throughout the whole operation. Paraplegia did not occur, Tarlov 2 paraparesis developed in four cases and three patients displayed cerebral damage. Intraoperative CSF--especially CSF-lactate--monitoring may help the operating team to detect early anaerobic changes of the metabolism the spinal cord.

Acid-Base Equilibrium↗

PubMed2000

[Popliteal artery entrapment syndrome].

Popliteal Artery Entrapment Syndrome (PAES) is an uncommon congenital anomaly. It arises due to compression of the popliteal artery by tendomuscular structures often combined with an anomalous position of the artery. Mostly young men are suffering of this disease. There are four common variations of this anomaly. We report on a 14 year old patient who had an acute 24 hours duration right leg ischemia caused by PAES. Using a posterior approach to the popliteal artery, following division of the accessory slip of gastrocnemius muscle we performed an arteriotomy and a floating thrombus was removed. The artery was reconstructed by direct continuous suture. One year postoperatively the boy has no complaints, peripheral pulse is palpable.

Adolescent↗

PubMed2000

[Effect of regional hypothermia on cerebrospinal fluid parameters during thoracoabdominal aorta clamping in dogs].

The most feared complication of thoracoabdominal clamping is the paraplegia or paraparesis following ischemic injury of the spinal cord. Early intraoperative recognition of this complication has not been solved yet. In our earlier experiment we found significant alterations of CSF glucose, lactate, pCO2 and Neuron Specific Enolase (NSE) levels during 60 minutes thoracoabdominal aortic clamping in dogs. The analysis of these parameters proved to be proper to follow metabolism of the spinal cord during this type of surgery. In our present paper we studied protective effect of regional hypothermia using peridural cooling by registration of above parameters. Statistical analysis of our data showed prevention of production of anaerobe metabolites in animals with icy peridural irrigation. The biochemical approach is appropriate for monitoring effectiveness of regional hypothermia of the spinal cord during aortic surgery.

Animals↗