1/2211. Unusual cause of intraoperative hypotension diagnosed with transoesophageal echocardiography in a patient with renal cell carcinoma. Transoesophageal echocardiography (TOE) is not commonly used in the management of non-cardiac cases. We report a case where the use of TOE played a major role in the intraoperative diagnosis and subsequent management of a patient exhibiting severe hypotension whilst undergoing a nephrectomy. The rare diagnosis of a secondary intraventricular tumour would not have been evident with more conventional monitoring techniques. ( info) |
2/2211. Fatal cardiac ischaemia associated with prolonged desflurane anaesthesia and administration of exogenous catecholamines. PURPOSE: Four cardiac ischaemic events are reported during and after prolonged anaesthesia with desflurane. CLINICAL FEATURES: We have evaluated desflurane in 21 consecutive patients undergoing advanced head and neck reconstructive surgery. Four deaths occurred which were associated with cardiac ischaemic syndromes either during or immediately after operation. All patients in the study received a similar anaesthetic. This comprised induction with propofol and maintenance with alfentanil and desflurane in oxygen-enriched air. Inotropic support (either dopamine or dobutamine in low dose, 5 micrograms.kg.min-1) was provided as part of the anaesthetic technique in all patients. Critical cardiovascular incidents were observed in each of the four patients during surgery. These were either sudden bradycardia or tachycardia associated with ST-segment electrocardiographic changes. The four patients who died had a documented past history of coronary heart disease and were classified American Society of Anesthesiologists (ASA) II or III. One patient (#2) did not survive anaesthesia and surgery and the three others died on the first, second and twelfth postoperative days. Enzyme increases (CK/CK-MB) were available in three patients and confirmed myocardial ischaemia. CONCLUSION: These cases represent an unexpected increase in the immediate postoperative mortality for these types of patients and this anaesthetic sequence. ( info) |
3/2211. Intraoperative loss of auditory function relieved by microvascular decompression of the cochlear nerve. BACKGROUND: Brainstem auditory evoked potentials (BAEP) are useful indicators of auditory function during posterior fossa surgery. Several potential mechanisms of injury may affect the cochlear nerve, and complete loss of BAEP is often associated with postoperative hearing loss. We report two cases of intraoperative auditory loss related to vascular compression upon the cochlear nerve. methods: Intra-operative BAEP were monitored in a consecutive series of over 300 microvascular decompressions (MVD) performed in a recent twelve-month period. In two patients undergoing treatment for trigeminal neuralgia, BAEP waveforms suddenly disappeared completely during closure of the dura. RESULTS: The cerebello-pontine angle was immediately re-explored and there was no evidence of hemorrhage or cerebellar swelling. The cochlear nerve and brainstem were inspected, and prominent vascular compression was identified in both patients. A cochlear nerve MVD resulted in immediate restoration of BAEP, and both patients recovered without hearing loss. CONCLUSION: These cases illustrate that vascular compression upon the cochlear nerve may disrupt function, and is reversible with MVD. awareness of this event and recognition of BAEP changes alert the neurosurgeon to a potential reversible cause of hearing loss during posterior fossa surgery. ( info) |
4/2211. Carotid endarterectomy and intracranial thrombolysis: simultaneous and staged procedures in ischemic stroke. PURPOSE: The feasibility and safety of combining carotid surgery and thrombolysis for occlusions of the internal carotid artery (ICA) and the middle cerebral artery (MCA), either as a simultaneous or as a staged procedure in acute ischemic strokes, was studied. methods: A nonrandomized clinical pilot study, which included patients who had severe hemispheric carotid-related ischemic strokes and acute occlusions of the MCA, was performed between January 1994 and January 1998. Exclusion criteria were cerebral coma and major infarction established by means of cerebral computed tomography scan. Clinical outcome was assessed with the modified Rankin scale. RESULTS: Carotid reconstruction and thrombolysis was performed in 14 of 845 patients (1.7%). The ICA was occluded in 11 patients; occlusions of the MCA (mainstem/major branches/distal branch) or the anterior cerebral artery (ACA) were found in 14 patients. In three of the 14 patients, thrombolysis was performed first, followed by carotid enarterectomy (CEA) after clinical improvement (6 to 21 days). In 11 of 14 patients, 0.15 to 1 mIU urokinase was administered intraoperatively, ie, emergency CEA for acute ischemic stroke (n = 5) or surgical reexploration after elective CEA complicated by perioperative intracerebral embolism (n = 6). Thirteen of 14 intracranial embolic occlusions and 10 of 11 ICA occlusions were recanalized successfully (confirmed with angiography or transcranial Doppler studies). Four patients recovered completely (Rankin 0), six patients sustained a minor stroke (Rankin 2/3), two patients had a major stroke (Rankin 4/5), and two patients died. In one patient, hemorrhagic transformation of an ischemic infarction was detectable postoperatively. CONCLUSION: Combining carotid surgery with thrombolysis (simultaneous or staged procedure) offers a new therapeutic approach in the emergency management of an acute carotid-related stroke. Its efficacy should be evaluated in interdisciplinary studies. ( info) |
5/2211. Profound hypothermia and circulatory arrest with skull base approaches for treatment of complex posterior circulation aneurysms. OBJECTIVE: cardiopulmonary bypass with profound hypothermia and circulatory arrest has seen a resurgence as an adjunct technique in neurological surgery. We report our experience with this technique in treating seven complex vertebro-basilar aneurysms. methods: skull base approaches were used in all cases, providing excellent exposure and minimizing brain retraction. There were six basilar artery aneurysms and one giant fusiform vertebro-basilar artery aneurysm. All aneurysms but one had an apparent neck, which could be clipped. The fusiform vertebro-basilar artery aneurysm was trapped, partially resected, and the circulation was reestablished with a saphenous vein graft from the cervical internal carotid artery to the mid-basilar artery. RESULTS: Five patients had an excellent outcome and two had a good outcome at one year or at latest follow up. Two of the patients showed improvement of neurological deficits which were present before the surgical intervention. CONCLUSION: Applying very strict selection criteria in this small series of patients with posterior circulation aneurysms, excellent or good results were achieved using the profound hypothermic circulatory arrest technique. ( info) |
6/2211. An uncommon mechanism of brachial plexus injury. A case report. PURPOSE: To report a case of brachial plexus injury occurring on the contralateral side in a patient undergoing surgery for acoustic neuroma through translabrynthine approach. CLINICAL FEATURES: A 51-yr-old woman underwent surgery for acoustic neuroma through translabrynthine approach in the left retroauricular area. She had a short neck with a BMI of 32. Under anesthesia, she was placed in supine position with Sugita pins for head fixation. The head was turned 45 degrees to the right side and the neck was slightly flexed for access to the left retroauricular area, with both arms tucked by the side of the body. Postoperatively, she developed weakness in the right upper extremity comparable with palsy of the upper trunk of the brachial plexus. hematoma at the right internal jugular vein cannulation site was ruled out by CAT scan and MRI. The only remarkable finding was considerable swelling of the right sternocleidomastoid and scalene muscle group, with some retropharyngeal edema. An EMG confirmed neuropraxia of the upper trunk of brachial plexus. She made a complete recovery of sensory and motor power in the affected limb over the next three months with conservative treatment and physiotherapy. CONCLUSIONS: brachial plexus injury is still seen during anesthesia despite the awareness about its etiology. Malpositioning of the neck during prolonged surgery could lead to compression of scalene muscles and venous drainage impedance. The resultant swelling in the structures surrounding the brachial plexus may result in a severe compression. ( info) |
7/2211. Intraoperative respiratory failure in a patient after treatment with bleomycin: previous and current intraoperative exposure to 50% oxygen. patients treated with bleomycin (BLM) are at risk of developing acute respiratory distress syndrome (ARDS) post-operatively, and this has been associated with high intraoperative concentrations of oxygen. We report progressive arterial desaturation noticeable 2 h after the start of a 4-h radical neck dissection for which the anaesthesia included 50% O2 in N2O. The patient had received two courses of bleomycin within the previous 2 months and had undergone an uneventful right hemiglossectomy under shorter but otherwise similar anaesthesia 4 weeks previously. His pulmonary function tests before the second procedure showed a slight depression of diffusing capacity (DLco) to 80% of predicted and minimal airway obstruction consistent with his history of smoking. The pulse oximetric reading during his second procedure reached 75%, but rose to 95% after treatment with methylprednisolone salbutamol and inspired O2 concentrations between 80% and 100%. By the end of the procedure, he satisfied the criteria for ARDS and was transferred to the ICU, where he developed bilateral pneumonia, deteriorated and died of multiple organ failure. This case suggests that the risk of hyperoxic pulmonary damage in patients exposed to bleomycin may increase not only with the degree and duration of hyperoxia in a given exposure, but also with the latent effects of recent previous exposure. Near normality of pulmonary function tests cannot be taken as reassurance, and small changes may have more adverse prognostic significance than in patients who have not been exposed to bleomycin. ( info) |
8/2211. Double anterior chamber deep lamellar keratoplasty: case report. PURPOSE AND methods: We report a case in which, although we planned to perform a penetrating keratoplasty for corneal stromal opacity with normal corneal endothelium, the host's Descemet's membrane became inadvertently detached and the operation resulted in double anterior chamber deep lamellar keratoplasty (DLKP). RESULT: After surgery, the patient's corrected visual acuity was 20/30. CONCLUSION: Double anterior chamber DLKP is safe and valuable. ( info) |
9/2211. mitral valve prosthesis disk embolization during transeptal atrioventricular junction ablation. We report a case of disk embolization from a Bjork-Shiley mitral valve prosthesis (Shiley Inc., Irvine, CA, USA) which occurred during transeptal atrioventricular (RV) junction ablation. The disk lodged in the lower thoracic aorta. The patient was treated successfully by emergency valve replacement, and the escaped disk has been left in situ with no complications. ( info) |
10/2211. Percutaneous transluminal coronary angioplasty as alternative treatment to coronary artery bypass surgery in iatrogenic stenosis of the left main coronary artery. The present report describes three patients with iatrogenic left main coronary artery after aortic valve replacement. All three patients were successfully treated by percutaneous transluminal coronary angioplasty. No clinical or angiographic signs of restenosis were seen during the long-term follow-up (4, 6, and 11 years). These patients show the feasibility of percutaneous transluminal coronary angioplasty in iatrogenic left main coronary artery stenosis as alternative of coronary artery bypass surgery. However, it should be only considered in patients who would otherwise be deemed inoperable, refused reoperation, and are willing to take the risk involved. ( info) |