Stump pressure and transcranial Doppler for predicting shunting in carotid endarterectomy.

OBJECTIVES: to compare stump pressure (SP) and transcranial Doppler (TCD) with neurologic monitoring during carotid endarterectomy (CEA). MATERIALS: one hundred and forty-seven CEAs performed under local anaesthesia. METHODS: neurologic monitoring and SP were performed in all cases, while mean velocity of the middle cerebral artery (mvMCA) by TCD was done in 140/147 (95%) cases. Shunts were applied in all cases on the basis of neurologic monitoring. The following haemodynamic criteria have been compared to neurologic monitoring: (a) <25 mmHg SP; (b) <50 mmHg SP; (c) < or =10 cm/s mvMCA after carotid occlusion; (d) > or =70 decrease of mvMCA after carotid occlusion. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated for each haemodynamic criterion. RESULTS: shunt was used in 18/147 (12.2%) cases. With regards to <25 mmHg SP, < or =50 mmHg SP, < or =10 cm/s mvMCA after carotid occlusion, and > or =70 decrease of mvMCA after carotid occlusion, sensitivity resulted 33, 89, 80 and 80%, respectively. Specificity resulted 96, 82, 97 and 96%, respectively. Positive predictive value resulted 55, 41, 75 and 71%, respectively. Negative predictive value 91, 98, 98 and 98%, respectively. Accuracy resulted 88, 76, 89 and 94%, respectively. CONCLUSIONS: none of the haemodynamic criteria by SP and TCD resulted absolutely reliable in predicting the need for carotid shunt.

Cerebral vasoreactivity does not predict cerebral ischaemia during carotid endarterectomy.

AIM: Assessment of cerebrovasoreactivity (CVR), obtained by transcranial Doppler (TCD) and the acetazolamide test to predict cases requiring selective carotid shunting on the basis of neurologic monitoring. METHODS: A consecutive series of 87 carotid endarterectomy (CEA) cases was studied. Before surgery CVR was evaluated by measuring the mean velocity of the middle cerebral artery (mvMCA) using TCD at the basal condition and at 30 min after intravenous administration of acetazolamide (1 g). Carotid shunting was performed using neurologic monitoring under local anesthesia. Receiver operating characteristic (ROC) curve was calculated for sensitivity and specificity for various CVR cut offs. RESULTS: The ROC curve demonstrated that there was no single CVR cut off with both sensitivity and specificity above 80%. CONCLUSION: The present study, which employed neurologic monitoring as the method of comparison, did not prove that CVR, as calculated by TCD and the acetazolamide test, is a valid preoperative test for predicting cerebral ischaemia caused by carotid clamping.

Cerebral haemodynamic aspects of severe carotid stenosis: asymptomatic vs symptomatic.

OBJECTIVES: to compare cerebral haemodynamics in patients with asymptomatic and symptomatic severe (> or =70%) internal carotid artery (ICA) stenosis. METHODS: we assessed 195 consecutive patients, 116 with asymptomatic carotid stenosis (ACS) and 79 with symptomatic carotid stenosis (SCS). Using transcranial Doppler we assessed cerebral vasoreactivity (CVR) following acetazolamide test, the middle cerebral artery flow velocity ratio after/before carotid clamping (mv-MCA ratio), and the carotid back pressure (CBP) during crossclamping. RESULTS: no significant differences between the two groups were demonstrated regarding CVR (47 vs 39%), mv-MCA ratio (50 vs 52%), or CBP (36 vs 44 mmHg). However, in patients with contralateral ICA occlusion all three variables were significantly lower as compared to patients with patent contralateral ICA. Also patients who needed a shunt during surgery had significantly lower values of mv-MCA ratio and CBP. Patients who suffered peri-operative neurologic deficits (n=6; 3%) did not differ from patients who had an uneventful course. CONCLUSIONS: clinical state of ICA stenosis is independent of cerebral haemodynamics. Occluded contralateral ICA is more important for predicting cerebral ischaemia caused by carotid clamping. Finally, none of the haemodynamic parameters showed predictive value for peri-operative neurologic morbidity.

Can cerebral vasoreactivity predict cerebral tolerance to carotid clamping during carotid endarterectomy?

Cerebral vasoreactivity (CVR) was evaluated as a preoperative test in predicting cerebral tolerance to carotid clamping.A consecutive series of 115 carotid endarterectomy (CEA) cases were studied. Before surgical operation CVR was evaluated, by measuring the mean velocity of the middle cerebral artery (mv-MCA) using transcranial Doppler (TCD) at the basal condition and 20 min after intravenous administration of acetazolamide (1 g). CEA was performed under general anesthesia. TCD was used during surgery to evaluate mv-MCA and to calculate mv-MCA clamping/mv-MCA pre-clamping x100 ratio (mv-MCA%), which was used as the parameter to validate CVR.CVR did not correlate with mv-MCA% (r=0.22). There was no significant difference (P=0.09) between mean values of the non shunted subgroup and the shunted one.CVR does not seem to be suitable for evaluating cerebral tolerance to carotid clamping.

External carotid artery shunting during carotid endarterectomy: an alternative for cerebral protection?

OBJECTIVES: to assess the application of external carotid artery (ECA) shunting in cerebral protection during carotid endarterectomy (CEA). DESIGN: prospective study. MATERIALS AND METHODS: the study comprised 137 consecutive patients who underwent CEA under locoregional anaesthesia. Transcranial Doppler was used to monitor the mean velocity of the middle cerebral artery (mv-MCA): (1) before carotid clamping; (2) after clamping both the common and external carotid arteries; (3) after clamping the internal carotid artery alone ("ECA test"). The decision to shunt was based on the occurrence of neurological deficit during carotid clamping. If the ECA test revealed mv-MCA approaching the pre-clamping values ECA shunting was used, whereas the remaining patients in need of a shunt had a standard internal carotid artery (ICA) shunt. RESULTS: shunting was necessary in 12/137 cases (9%). The ECA test indicated that in four cases - 3% of the whole series or 33% of the shunted cases. In these four patients ECA shunting reversed the neurological deficit, and CEA was successfully performed without any complications. CONCLUSIONS: ECA shunting could be considered as an alternative to standard ICA shunting. Suitable cases can be identified on the basis of the ECA test.

Impact of co-amoxiclav on polymorphonuclear granulocytes from chronic hemodialysis patients.

Phagocyte-dependent host defenses are frequently impaired in maintenance hemodialysis patients who show an increased susceptibility to infections. In these individuals, the course of infections can be more aggressive than in normal hosts, and the antibiotic of choice should have a high antimicrobial effect without impairing host defenses. Hence, in uremic patients, the antibiotic enhancement of phagocyte functions may be of potential clinical importance in the outcome of bacterial infections. Because we demonstrated previously that co-amoxiclav had beneficial properties that result in enhancement of the microbicidal functions of human polymorphonuclear cells (PMNs) from healthy subjects, we investigated the influence of this combination on the activities of PMNs from chronic hemodialysis patients against Klebsiella pneumoniae, a human pathogen that can pose severe problems in patients whose immunity is impaired. PMNs from chronic dialysis patients showed a diminished in vitro phagocytic efficiency with a reduced phagocytosis and bactericidal activity towards intracellular K. pneumoniae compared with that seen in PMNs from healthy subjects. When co-amoxiclav was added to PMNs from chronic hemodialysis patients, it was able to restore the depressed primary functions of PMNs, resulting in a significant high increase in both phagocytosis or killing activity. A similar pattern was detected with PMNs collected from hemodialysis patients treated with co-amoxiclav. The results of the present study provide evidence that co-amoxiclav is able to induce stimulation of depressed phagocytic response of PMNs from patients on chronic hemodialysis, restoring their primary functions both in vitro and in vivo.

Predictive value of transcutaneous oximetry for selection of the amputation level.

BACKGROUND: Transcutaneous oximetry was studied to select the correct amputation level for limb ischemic necrosis with possible identification of threshold value. METHODS: The method was evaluated in 30 cases (20 patients, 5 males and 15 females, of ages ranging from 61 to 93, average 73.1+/-8.5) where patients underwent amputation because of severe leg ischemia. Surgical operations were: minor amputation (toe or transmetatarsal) in 23 cases, below knee amputation in 7. Oxygen tension was measured at the dorsum foot and at the third superior of the anteromedial calf aspect. RESULTS: Results were classified as success (primary or delayed healing) or failure (necrosis at the surgical wound). Amputation was successful in 17/30 cases with oxygen tension of 0-65 mmHg (mean 32.5+/-16.1) and failed in 13/30 with oxygen tension of 0-57 mmHg (mean 7.8+/-17.3). The difference was statistically significant (p=0.0004). Sensitivity of the method resulted 88.2%, specificity 84.6%, diagnostic accuracy 86.7%, positive predictive value 88.2% and negative predictive value 84.6%. A threshold of 20 mmHg was identified: 15/17 successful cases showed values greater than 20 mmHg, while 11/13 failed cases presented values lower than the threshold. CONCLUSIONS: Following our observations and according to some reported studies, we believe transcutaneous oximetry to be the best method for selection of amputation level This is a simple, noninvasive and accurate method, which has showed itself superior to other techniques (i.e., Doppler and radioisotope).

[Surgical management of asymptomatic carotid artery stenosis. Authors' experience, problems and prospectives]. / La chirurgia della stenosi carotidea asintomatica. Nostra esperienza, problemi e prospettive.

BACKGROUND: Some trials have demonstrated effectiveness of carotid endarterectomy (CEA) for preventing stroke in patients with severe symptomatic carotid stenosis. Although some researches, indication to surgery for asymptomatic carotid stenosis is debated up today. Based on personal experience and literature, the main problems of CEA for asymptomatic stenosis are discussed. DESIGN: Retrospective study. SETTING: Section of Vascular Surgery, University Department. PATIENTS: CEA was performed in a consecutive series of 63 cases with asymptomatic stenosis (59 patients, 40 males and 19 females, ages ranging from 46 to 80 years, mean 67.9). INTERVENTIONS: CEA was performed under general anesthesia, with primary closure of arteriotomy in 37 cases and patch angioplasty using PTFE in 24, using eversion technique in 2 cases. Pruitt-Inahara shunt was used in 10/63 cases (15.9%), according to the mean velocity of the middle cerebral artery at carotid clamping/mean velocity of the middle cerebral artery pre-clamping ratio x 100 equal to or lesser than 15%, evaluated with transcranial Doppler, or stump pressure lesser than 50 mmHg, when transcranial Doppler examination was not possible. MEASURES: Operative mortality and postoperative morbidity. RESULTS: Operative mortality plus postoperative stroke were 1.6% (1/63). Operative mortality was precisely 0.0%. Postoperative complications were two: one was a neurologic deficit (monoparesis of the arm) and the other was myocardial ischemia. CONCLUSIONS: Four main problems have been shown in CEA for asymptomatic stenosis: 1. Identification of asymptomatic stenosis: 2. Assessment of risk for stroke: 3. Role of CEA: 4. Questions about surgical treatment. For the first problem, it is important to consider possible indicators for carotid stenosis (contralateral carotid stenosis, coronary artery disease, aortic aneurysm, peripheral arterial disease, etc.). With regard to the second problem, it is important to know the natural history of the carotid stenosis, which shows a stroke rate of 1-2% per year. Regarding the third problem, the role of CEA is conditioned by: trials, patient conditions, lesion characteristics and ability of the surgeon. Further studies should identify some groups of patients (with severe carotid stenosis, dyshomogeneous plaque, progression of plaque, etc.), who can profit from CEA. Finally (fourth problem), CEA for asymptomatic carotid stenosis carries all common problems of carotid surgery (preoperative assessment, evaluation of cerebral ischemia due to carotid clamping, shunt, closure of arteriotomy, etc.). Some of these problems can receive ultimate solutions from some studies in next years.

[Surgery of recurrent varices of the minor saphenous vein]. / Chirurgia delle varici recidive della vena piccola safena.

BACKGROUND: Investigation of the diagnostic and technical problems of redo surgery of the lesser saphenous vein for primary varicose veins. DESIGN: a retrospective study. SETTING: Section of Vascular Surgery in a University Hospital. PATIENTS: Fifteen lower extremities were operated upon (13 patients, 3 males and 10 females, ages ranging from 43 to 65 years with a mean of 53.2). INTERVENTIONS: Each case was assessed by clinical examination, duplex scanning and venography (ascending venography and/or varicography). Surgical procedure was carried out via a longitudinal approach over the popliteal region or the posterior aspect of the thigh. Each case presented with a stump of the lesser saphenous vein. MEASURES: Hemodynamic (correction of reflux of the lesser saphenous vein) and clinical (improvement of clinical state in the operated lower limb and complications) results were evaluated. RESULTS: Reflux at the ostium of the lesser saphenous vein was corrected in 15/15 (100%) cases. Clinical result was good in 15/15 (100%) cases. Postoperative edema was observed in 7/15 (46.7%) cases. Lesion of the common peroneal nerve with paresis of the foot dorsal flexion was found in 1/15 (6.7%) cases. Hypertrophic scar was observed in 4/15 (26.7%) cases. CONCLUSIONS: Redo surgery of the lesser saphenous vein is requested less frequently than other surgical procedures for superficial venous diseases. This surgery requires two essential features: a) accurate diagnosis of the lesser saphenous vein insufficiency; b) adequate surgical technique. For the former purpose, venography is a fundamental method of assessment. Surgical technique should be cautious and gentle. A longitudinal approach leads to a wide exposure of the structures in the popliteal fossa.

[Iliac vein insufficiency syndrome. Clinical contribution]. / La sindrome da insufficienza della vena iliaca interna. Contributo clinico.

BACKGROUND: Definition of essential findings in chronic venous insufficiency without valvular incompetence of the greater and/or lesser saphenous vein and due to reflux in the system of the internal iliac vein. DESIGN: a retrospective study. SETTING: Section of Vascular Surgery in a University Hospital. PATIENTS: Five patients, all females, ages ranging from 24 to 62 years, (6 lower extremities) with internal iliac venous insufficiency syndrome were identified. INTERVENTIONS: Each case was assessed with clinical examination, Doppler CW and venography. Moreover, all cases were surgically treated using the technique of varicose vein avulsion. MEASURES: Venographic picture and results of surgical treatment were evaluated. RESULTS: Reflux in the system of the internal iliac vein was demonstrated in all cases. Connections between this vein and subcutaneous varicose veins network were identified using venography. Surgical treatment has given good results in 5 lower extremities followed-up from 6 months to 3 years, while recurrent varicose veins were observed in 1 leg after 6 months. CONCLUSIONS: Syndrome of internal iliac vein insufficiency requires more attention than in the past. As to diagnostic evaluation, venography (particularly varicography) plays an essential role. The best treatment is stab avulsion of varicose vein, if pelvic congestion syndrome is excluded.

Advantages of the lateral approach for re-exploration of the sapheno-femoral junction for recurrent varicose veins.

Re-exploration of the sapheno-femoral junction for recurrent varicose veins presents many problems. The lateral approach to the sapheno-femoral junction via a groin incision as previously described was performed in 109 lower limbs. The operative mortality rate was 0%. Functional outcome was good in 106 cases (97.2%) and only in three (2.8%) did recurrent varicose veins occur in the upper thigh. Complications were mainly lymphorrhoea (six cases, 5.5%). Cosmetic results were also satisfactory. This surgical procedure allows an easy and safe approach to the sapheno-femoral junction and avoids damage to femoral vessels. Recurrence was rare and caused by incompetent communicating veins in the upper thigh. These characteristics make the lateral approach the preferred technique for re-exploration of the sapheno-femoral junction.

[Surgical interventions in dialysis patients in Piedmont: data from the Regional Registry. Working Group of the Piedmont Registry of Dialysis and Transplantation]. / Interventi chirurgici nei pazienti in dialisi in Piemonte: dati dal Registro Regionale (RPDT). Gruppo di lavoro dell'RPDT.

In this work surgical events in a large population of chronic dialysis patients are analysed. Data are obtained from the Regional (Piedmont) Registry of Dialysis and Transplantation (RPDT), that has collected information since 1981 about all chronic dialysis patients in the Region. Since 1984, causes of admission to-hospital are registered. Surgical causes of hospitalization, for purposes not related to uremia, were 538 (20% of all surgical admissions). In patients younger than 65 years, these hospitalizations account for about 6% of the cases, whereas in patients older than 65 they are less than 5%. As expected, a higher number of surgical operations is observed in diabetics, while on the contrary the lowest is performed in nephroangiosclerosis patients. Cardiovascular and bowel diseases represent almost 50% of all surgical needs. Postoperative mortality was 5.8% within 45 days from admission. Cardiac and infectious diseases and cachexia represent the more frequent causes of death. In 27 out of 28 cases at least one high risk condition was present.

[Automated peritoneal dialysis (APD). Experience in 42 patients]. / La dialisi peritoneale automatizzata (APD). Esperienza in 42 pazienti.

Automated peritoneal dialysis (APD) is currently considered as one of the most attractive home treatments for uremic patients. However, relevant costs and the presence of a dialysis machine prevent a wider diffusion of this technique. In this work we discuss the results obtained in 42 patients (12 females, 30 males) treated by two dialysis units of the Piedmont Region. Patients' characteristics. Eighty-three percent of the females and 66.5% of the males are under 65 years of age; glomerulo-nephritis and nephroangiosclerosis account for the most frequent renal diseases (28.5 each); a high risk condition is recorded in 52.5% of cases. Twenty-two patients were transferred to APD from CAPD (patient's request in 59% of cases, clinical problems in the remaining). RESULTS. Forty-five percent of cases are working full or part-time, 12% are not caring for self. Peritonitis rate accounts for 1 episode every 42 patient-months. Biochemical control is satisfactorily achieved (mean values: urea 137.8 mg/dl, creatinine 11 mg/dl, calcium 10.2 mg/dl, phosphate 5.7 mg/dl, albumin 4.3 g/dl, cholesterol 234 mg/dl, triglycerides 195 mg/dl). Technical assistance was requested on average once every 16 months of treatment. CONCLUSION. Negative drawbacks of APD, mainly related to elevated costs and technical complexity, are fully counterbalanced by satisfactory social and clinical rehabilitation, wider indications to peritoneal dialysis with respect to CAPD, lower rates of peritonitis and limited technical needs.

Death in conditions of cachexia: the price for the dialysis treatment of the elderly?

Death in conditions of cachexia is increasing in potential dialysis patients, as treated cohorts are aging, the mean age of new patients increased and access to treatment is unlimited. The present study analyzes the clinical features of 417 deaths in conditions of cachexia recorded in 1981 to 1990 in the Dialysis and Transplantation Registry of a northern Italian region, Piedmont (about 4,400,000 inhabitants, 20 dialysis centers; 4,734 patients on file at December 31, 1990; yearly information on 100% of the cases). Death in conditions of cachexia increased from 105 cases in the first four years taken into account (1981 to 1984), to 107 in the last two years (1989 to 1990). Prevalence is higher in the elderly (85% of the death over age 60). Most patients (90.5%) were at high clinical risk. To assess whether the frequency of this diagnosis reflected the wide acceptance of elderly patients for dialysis and was a marked of vascular disease, a specific inquiry was conducted about 107 cachectic deaths recorded from 1989 to 1990: 82.5% of the patients had diffused vascular disease, 11.5% were already cachectic when dialysis was initiated, and 66% were in cachexia at least six months before death. Since mean age of patients dying in condition of cachexia increased from 68.8 in the period of 1981 to 1984 to 70.3 years in 1989 to 1990, and mean time on dialysis from 2.8 years in 1981 to 1984 to 70.3 years in 1989 to 1990, the higher prevalence is not likely to be due to lack of care of elderly patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Erythrocyte Na-stimulated Mg transport in uremic patients undergoing CAPD.

A derangement of magnesium homeostasis with hypermagnesemia and increased intraerythrocyte Mg content [Mgi] has been described in uremic patients, and could play a pathogenetic role in both alterations of bone metabolism and vascular reactivity, observed in these patients. Recently Féray and Garay described in human erythrocytes a transport system which catalyzes outward Mg movements in the presence of external Na. These fluxes may be responsible for maintaining and regulating a low [Mgi]. The aim of this study was to evaluate in 16 normal subjects and 14 uremic patients undergoing CAPD: [Mgi] and rate of Na-dependent and Na-independent Mg efflux in Mg-loaded erythrocytes, in order to maximally stimulate Mg efflux. Mean plasma and intraerythrocyte Mg concentrations were significantly higher in CAPD than in normal subjects (1.09 +/- 0.20 vs 0.86 +/- 0.004 mmol/l, p less than 0.001 and 2.57 +/- 0.38 vs 1.96 +/- 0.18 mmol/l RBC, p less than 0.001). After an in-vitro Mg load, the intraerythrocyte Mg concentration and Na-independent Mg efflux were similar in both groups (17.5 +/- 1.4 vs 18.2 +/- 4.1 mmol/l RBC and 152 +/- 20 vs 126 +/- 19 mumol/l RBC/h). However, the Vmax of erythrocyte Na-stimulated Mg efflux was significantly higher in CAPD patients than in normal subjects (357 +/- 48 vs 229 +/- 88 mumol/l RBC/h, p less than 0.02). [Mgi] and the rate of Na-dependent Mg efflux were inversely related in CAPD patients (r = -0.76; p less than 0.002). These results indicate that uremic CAPD patients have a [Mgi] and Vmax of erythrocyte Na-dependent Mg efflux higher than normal subjects; this could reflect a compensatory, although insufficient, mechanism against high levels of intraerythrocyte Mg concentration, as suggested by the correlation between [Mgi] and the rate of Na-dependent Mg efflux.