Management of blunt splenic trauma in patients older than 55 years. Southern Connecticut Regional Trauma Quality Assurance Committee.

BACKGROUND: Many experts have suggested that blunt splenic trauma in patients older than 55 years should not be managed by observation because of supposed increased fragility of the spleen and decreased physiologic reserve in elderly patients. We sought to determine the outcome of nonoperative management of blunt splenic trauma in patients older than 55 years. METHODS: For the years 1994 through 1996, data for patients with splenic injury older than 55 years from seven trauma centers in a single state were reviewed. RESULTS: Blunt splenic trauma occurred in 41 patients older than 55 years. Eight patients were excluded from further analysis because of death from massive associated injuries within 24 hours of admission. The remaining 33 patients (mean age, 72+/-10 years) were divided into two groups: immediate exploration (10 patients) and observation (23 patients). Observation of blunt splenic injury failed in 4 of 23 patients (17%). No patient deaths were related to the method of management of the splenic injury. CONCLUSIONS: Observation of the elderly patient with blunt splenic trauma has an acceptable failure rate of 17%.

A primate model for the study of the interaction of 111In-labeled baboon platelets with Dacron arterial prostheses.

This paper presents early experience with a primate model for the noninvasive study of the interaction of circulating platelets with healing arterial prostheses. These experiments demonstrate that baboon platelets can be isolated and labeled with 111Indium with high efficiency using a sterile technique. Platelets subjected to this process have a linear life span similar to that of 51Chromium-labeled baboon platelets. The high energy gamma emission of 111Indium oxine allows for external scanning using a standard gamma camera. The small quantity of 111Indium-labeled platelets in the region of the graft can be discriminated from the surrounding blood vessel and quantitated by gamma camera imaging and computer analysis. There was a significant increase in the platelet deposition on prosthetic surfaces observed 5--48 hours after graft implantation and injection of 111Indium-labeled autologous platelets.

The relative value of carotid noninvasive testing as determined by receiver operator characteristic curves.

To determine the relative value of carotid phonoangiography (CPA), oculoplethysmography-Kartchner (OPG-K), and Doppler ultrasonic arteriography (UA), 90 vessels undergoing carotid endarterectomy were prospectively examined. By analyzing the data on receiver operator characteristic curves, the dynamic relationship between sensitivity and specificity for each of the three noninvasive tests was assessed. Disease was defined by either the percentage of angiographic stenosis or the mean pressure gradient across the carotid (deltaP). All three tests were shown to be relatively insensitive, but quite specific, if disease was defined by 50% and 60% angiographic stenosis or deltaP of greater than 10 and 20 mm Hg. By employing a more rigid definition of disease, 70% stenosis or deltaP of greater than 30 mm Hg, sensitivity was increased for all examinations and was highest in OPG-K and UA for a given specificity. The sensitivity for UA was enhanced to 80% with a comparable specificity, if those 23 UA exams with plaque were treated as positive studies. The combination of CPA, OPG-K, and UA was superior to any one of these tests alone, but the best value balancing maximum sensitivity and specificity still was associated with a 23% false negative rate. This study would suggest that these three tests should be limited to screening patients at risk for carotid stenosis and not for symptomatic patients. To achieve the best balance between sensitivity and specificity, lax threshold criteria for calling the test positive should be employed, and the tests should be used in combination.

Failure of carotid stump pressures. Its incidence as a predictor for a temporary shunt during carotid endarterectomy.

A total of 289 carotid endarterectomies were performed in 204 patients. A decision to place a temporary shunt during carotid endarterectomy in this series was made entirely on the basis of intraoperative EEG monitoring. Retrospectively, the correlation between stump pressures and the results of intraoperative EEG monitoring in each case was determined. Evidence of ischemia developed in 6% of the total series on intraoperative EEG monitoring despite a stump pressure of greater than 50 mm Hg. The degree of disagreement between stump pressure and EEG varied according to clinical category in this series. In those endarterectomies performed for completed stroke, all cases requiring shunting had stump pressures less than 50 mm Hg. In those cases performed for symptoms of vertebral basilar insufficiency, however, 77% of the cases requiring an intraoperative shunt had stump pressures greater than 50 mm Hg. A review of the complication rate in the various study groups indicates that the use of intraoperative EEG is a safe indicator of cerebral ischemia during carotid endarterectomy regardless of stump pressure.

Prophylactic interruption of the inferior vena cava: immediate and long-term hemodynamic effects.

Two hundred patients were evaluated retrospectively to determine the clinical effects of prophylactic inferior vena cava (IVC) interruption in association with aortic reconstruction. No pulmonary embolism occurred in the group with IVC interruption, but embolisms did occur in seven of 68 patients who had aortic reconstruction performed without IVC interruption. In two patients, the pulmonary embolism was fatal. Postoperative incidence of deep vein thrombosis was fatal. Postoperative incidence of deep vein thrombosis was 9% in both groups. Clinical and hemodynamic effects of prophylactic IVC interruption were studied in 20 additional patients. Venous hemodynamics (maximum venous outflow, inferior vena cava pressure, and ambulatory venous pressure) showed no change following interruption in 19/20. Sixteen patients from the original group of patients with prophylactic interruption were studied hemodyamically. No pulmonary embolism was clinically evident. One new case of deep vein thrombosis was seen. Again, venous hemodynamics showed no change as a result of IVC interruption. Prophylactic IVC interruption is a safe means of decreasing the incidence of pulmonary embolism without increasing venous-related morbidity.

A prospective study of Doppler pressures and segmental plethysmography before and following aortofemoral bypass. Implications for predicting success and for adopting a uniform method of classifying arterial disease.

To determine the clinical and hemodynamic changes associated with aortofemoral bypass, 44 limbs of 31 patients underwent segmental plethysmography (PVR) and Doppler pressures (DSP) before operation, immediately after operation, and again at 6 months. Prior to operation patients were separated by angiographic criteria into two groups: aortoiliac segment disease alone (AI) (n = 22), and aortoiliac and femoropopliteal segment disease (AIFP) (n = 22). At 6 months the two groups were subdivided into four groups based on relief (oSx) or lack of relief (+Sx) of symptoms. Before operation the only significant difference between the four groups was a higher thigh PVR and calf DSP in the AI + Sx group. Six month PVR values in AIoSx were improved nearly twofold over preoperative measurements at the thigh and calf, but at the thigh level only for AIFPxSx. DSP was increased at all three levels in both AI and AIFPoSx groups. No hemodynamic improvement occurred in either the AI or the AIFP + Sx groups. A derivative index of PVR (thigh-ankle/15 mm) or the FPomega was significantly lower in AIFOsSx before operation. There was a significant disparity between classification by hemodynamics and by symptoms prior to operation which lessened somewhat after operation. These studies suggest that success or failure can be predicted before operation in AIFP by FPomega, and arterial disease should be classified by a combination of symptoms, angiography, and hemodynamics.