Giorgio Tiberio

Monitoring of Somatosensory Evoked Potentials During Carotid Endarterectomy: Relationship with Different Haemodynamic Parameters and Clinical Outcome

The authors studied the changes of Somatosensory Evoked Potentials (SEPs) performed in 241 anaesthetised patients during 264 carotid endarterectomies (CEs). SEP responses were considered significantly modified when the central conduction time was greater than 1 ms and/or when the amplitude of the complex N20-P25 decreased by at least 50%. Both CCT and N20-P25 have been correlated with different parameters, including the presence or absence of preoperative neurological deficits, the type of general anaesthesia, the status of the contralateral and the ipsilateral carotid artery, stump pressure, the use of an intraluminal shunt and the perioperative results. After carotid cross-clamping SEP responses were within the normal range in 236 CEs (89%), and abnormal in 28 (11%). A shunt was inserted 23 times in 264 (9%) cases. None of the patients operated on in this series experienced a permanent neurological deficit; there were three (1.1%) transient deficits (two Rinds and one TIA) and two deaths from non-neurological causes. Only one of the transient deficits was present when the patient woke from the anaesthetic and this event was predicted by significant modification of the SEP which did not reverse after removal of the clamps (a shunt was not used). None of the patients in our series who did not present significant modifications of SEPs during the operation had any postoperative neurological deficit. The authors conclude that SEP recording is a highly reliable and objective method for continuous monitoring of brain function during CE.

Value of Doppler Multi-Level Segmental Pressure Index in the Diagnosis and Hemodynamic Characterization of Totally Occlusive Aorto-Iliac-Femoro-Popliteal Lesions

Four-level lower limb Doppler S.P.I. (upper thigh; above knee; below knee; above ankle) were evaluated in 275 limbs, 110 of which showed totally occlusive lesions at one or more levels of the aorto-iliac-femoro-popliteal axis on angiographic examination, 65 showed stenosis < 50% (sclerotic controls) and 100 did not undergo arteriographic examination since they apparently had no lesions (healthy controls) . Analysis of the results - carried out using the Students t statistical method - showed a drop in the S.P.I. close to or over 0.30 between two adjacent levels and was indicative of the presence of an occlusion in the intermediate area. This method therefore allowed the presence and the position of an isolated lesion to be detected. In the case of multiple lesions in series, the proximal one is detected with certainty, whereas the more distal ones can be recognized but not their exact position and extension. Multiple lesions in series are more hemodynamically significant than isolated ones, and proximal lesions more than distal ones.

Study of Peripheral Flow During Successful Aortoiliac and Aortofemoral Prosthetic Reconstructions by Intraoperative Above-Ankle Pressure Index Monitoring

Doppler above-ankle pressure index (API) was monitored during 368 consec utive bilateral aortoiliac or aortofemoral graft reconstructions performed for aneurysmal or occlusive disease. The aim of this study was to investigate the variations of peripheral pressure, during and just after completion of the proce dure, either when followed by immediate and definitive success or when an intraoperative correction or an early postoperative reoperation was necessary owing to postreconstructive ischemia. For this purpose the API courses were subdivided into three groups: A (705 limbs), which underwent immediately suc cessful reconstructions; B (22 limbs), which needed intraoperative correction; C (9 limbs), which required early reoperation. All 736 limbs were studied individ ually as monolateral reconstructions and classified into six subgroups: 1, pervi ous iliac, pervious femoral artery; 2, occluded iliac, pervious femoral; 3, pervi ous iliac, stenotic femoral (i.e, stenosis > 75% of the superficial femoral artery); 4, occluded iliac, stenotic femoral; 5, pervious iliac, occluded femoral; 6, oc cluded iliac, occluded femoral. APIs were monitored before the operation (PRE), at the completion of the distal anastomosis (DEC), and five, fifteen, thirty, and forty-five minutes after. Data were statistically analyzed by multivariate analysis in regards to 705 immediately successful limbs (group A) and by comparison of all corrected or reoperated cases (groups B and C) with the lower bound of the fifth centiles of group A. The results in group A show that: API-PRE is different in the six subgroups (p < 0.001); API-DEC is lower than API-PRE in the patent iliac artery sub groups (1,3, and 5) and higher than API-PRE in the occluded iliac artery sub groups (2,4, and 6) (p always < 0.001). From declamping time to the forty-five- minutes observation, the mean courses turn out parallel and rising but on dif ferent levels (p < 0.001): pervious femoral, stenotic femoral, occluded femoral. API-forty-five minutes is higher than API-PRE in occluded iliac artery subgroups (2, 4, and 6) (p < 0.001), whereas in the patent iliac artery subgroups only the fifth subgroups reveals a slight but significant rise (p < 0.01), probably owing to the high rate of profunda femoral endarterectomy or angioplasty asso ciated with aortofemoral reconstructions. APIs values of 31 cases in groups B and C, compared with the lower bound of the fifth centile of group A, show that 8/31 cases (26%) remain above that bound, while 23/31 cases (74%) fall below it.

Immediate detection of postreconstructive ischaemia by intra-operative Doppler ankle pressure index monitoring during aortic reconstructions

From March 1980 to February 1988, 368 aorto-iliac or aorto-femoral bilateral reconstructions were performed for aneurysmal or occlusive disease. In order to demonstrate early postreconstructive ischaemic complications, the intra-operative Doppler Ankle Pressure Index (API) was measured immediately before reconstruction (PRE), just after declamping (DEC) and 5, 15, 30 and 45 min thereafter. Each limb of the reconstruction (736) was considered individually and subdivided as follows: Group (A) 705 immediately successful (96% of limbs and 92% of patients); Group (B) 22 (3% of limbs and 5% of patients) in which, on the grounds of API data, an ischaemic complication was regarded as imminent and treated by graft revision or a peripheral thromboembolectomy (intra-operative corrections); Group (C) 9 (1% of limbs and 2% of patients) in which the diagnosis of ischaemic complications was made postoperatively when the patients underwent successful reoperation. All 736 reconstructions were patent and functional at discharge of the patient. By a retrospective analysis the intra-operative APIs were studied and the features (single or associated) suggesting an ischaemic complication examined. These were: (1) no flow at the time of declamping or its disappearance during the operation (10 cases, 1.25% of limbs) all detected and successfully corrected intra-operatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical Techniques from Intraoperative Angiographic and Velocimetric Controls in 43 Consecutive Carotid Bifurcation Endarterectomies

From January to November, 1985, 43 carotid bifurcation endarterectomies (CE) were performed with intraoperative functional (Doppler spectrum analy sis) and morphologic (angiography) controls. In the first 20 cases, after thromboendarterectomy and direct suture, Dop pler showed absence of or no significant variations of frequency in 17 cases, a frequency increase corresponding to a less than 45% diameter reduction steno sis at the apex of the suture in 2 cases, and no flow in the internal carotid artery (ICA) in 1 case. Angiography confirmed the thrombosis in the above mentioned case and showed 3 less than 50% stenoses at the distal end of the arteriotomy: 2 already recognized by Doppler in small-size ICAs and 1 in a medium-size ICA without significant changes of flow. The reason for thrombosis was a distal intimal flap, which was successfully removed; the 2 stenoses in which Doppler and angiography agreed were corrected by patch angioplasty. In the last 23 cases, patch angioplasty was performed routinely in small-size ICAs (6 cases); in 1 case, first treated by a direct suture, Doppler and angiography showed a medium-grade stenosis, immediately corrected; in 1 case both techniques showed a 50% stenosis in a common carotid artery, immediately corrected. The execution of intraoperative angiography in this group of patients al lowed the authors to define the indication for the use of patch angioplasty, never previously employed. Nevertheless, the authors state that, on account of loss of time, costs, and exposure to radiations, intraoperative angiography must be reserved for those cases selected by Doppler spectrum analysis. This method seems to be highly sensitive in recognizing significant technical defects that could lead to an immediate or late failure.

Blunt Trauma Injury of the Caval Junction A Case Treated with PTFE Patch Angioplasty

A case report of caval bifurcation injury associated with right common iliac artery throm bosis sustained after a blunt trauma to the abdomen is presented. Different problems are encountered in the management of this type of lesions. These are related to trans portation, resuscitation techniques, and diagnosis and, in the operating room, to an adequate exposure, control of hemorrhage, and vascular reconstruction. A repair of the caval junction has been performed successfully using a polytetrafluoroethylene patch, avoiding stenosis of the lumen, and restoring blood flow in the vena cava. No compli cations such as thromboembolism have been reported and patency has been verified at a four month follow-up.

Iatrogenic extracranial carotid dissection : report of two cases treated surgically

Two patients had an acute dissection of the right common carotid artery due to catheterization of the vessel during Seldinger angiography. Both patients were evaluated immediately after the traumatic event by means of echo-pulsed Dop pler (duplex scan) to check the hemodynamic significance of the lesion. In the first case, the lesion initially appeared insignificant, but on the second day duplex scanning showed a sudden reduction of the flow in the internal carotid artery due to progression of the carotid dissection: the patient, neurologically asymp tomatic, was operated on successfully. The second patient, also asymptomatic, underwent emergency surgical treat ment after the first duplex scan showed significant reduction of the internal carotid flow. The postoperative course has been uneventful. Both patients are asympto matic eighteen and eight months after surgery. The authors emphasize the important role that duplex ultrasonography played in the management of these 2 patients.