Biomedical subjects

Phillip J Bendick

Publications and source records attributed to Phillip J Bendick.

23 records · Page 2Linked to original sources

PubMedDate not supplied

Duplex ultrasound imaging with an ultrasound contrast agent: the economic alternative to CT angiography for aortic stent graft surveillance.

The use of endovascular stent graft repair for aortic aneurysmal disease has become increasingly common, with the added requirement for close postoperative surveillance to detect the presence of endoleaks or graft migration. The most commonly used technique for surveillance is computed tomography (CT) angiography, with the need for intravenous contrast posing 1 limitation in those patients with renal dysfunction and the cost of this testing presenting an economic limitation. Early results of duplex imaging in the authors' Vascular Laboratory using an intravenous ultrasound contrast agent have shown sensitivity and specificity equivalent to those of CT angiography, with no evidence of any related morbidity. They have evaluated the cost effectiveness of using duplex ultrasound imaging as the primary surveillance technique for postoperative follow-up in aortic stent graft patients. Surveillance protocols now require that 8 follow-up examinations be performed in the first 3 years after stent graft placement. The charges for CT angiography in their institution average 2,779 dollars per study, for a 3-year total of 22,232 dollars per patient. The charges for aortic duplex ultrasound average 525 dollars per study, with a 3-year total of 4,200 dollars per patient. Adding the cost of routine abdominal radiographs to confirm stent graft position (147 dollars per study) would bring this 3-year total to 5,376 dollars, a savings of 16,856 dollars per patient. For every 100 patients who are followed up after stent graft placement, this represents a 3-year savings of more than 1.6M dollars. Promising early results of duplex ultrasound imaging with an intravenous contrast agent show sensitivity and specificity equivalent to those of CT angiography in detecting aneurysm size and graft endoleaks or other hemodynamic abnormalities. If these results can be demonstrated in larger patient series, this technique should become the method of choice for stent graft surveillance, for it offers very significant economic advantages and avoids the complications of intravenous contrast-induced renal dysfunction.

Blood Vessel Prosthesis Implantation↗

PubMedDate not supplied

Hypothermia is an independent predictor of mortality in ruptured abdominal aortic aneurysms.

Hypothermia is known to significantly increase mortality in trauma patients, but the effect of hypothermia on outcomes in ruptured abdominal aortic aneurysms (RAAA) has not been evaluated. The authors reviewed their experience from 1990 to 1999 in 100 consecutive patients who presented with RAAA and survived at least to the operating room for surgical treatment. There were 70 men and 30 women, with a mean overall age of 74 +/-8 years. Overall mortality was 47%. Univariate ANOVA (analysis of variants) showed significant correlation with mortality for decreased intraoperative temperature, decreased intraoperative systolic blood pressure, increased intraoperative base deficit, increased blood volume transfused, increased crystalloid volume (all p < 0.001); decreased preoperative hemoglobin (p = 0.015); and increased age (p = 0.026). Patient sex, initial preoperative temperature, preoperative systolic blood pressure, and operating room time were not correlated with mortality in the univariate analysis. Using these same clinical variables, multiple logistic regression analysis showed only 2 factors independently correlated with mortality: lowest intraoperative temperature (p = 0.006) and intraoperative base deficit (p = 0.009). The mean lowest temperature for survivors was 35 +/-1 degrees C and for nonsurvivors 33 +/-2 degrees C (p < 0.001). When patients were grouped by lowest intraoperative temperature, those whose temperature was < 32 degrees C (n = 15) had a mortality rate of 91%, whereas patients with a temperature between 32 and 35 degrees C (n = 50) had a mortality rate of 60%. In the group that remained at or > 35 degrees C (n = 35) the mortality rate was only 9%. A nomogram of predicted mortality versus temperature was constructed from these data and showed that for temperatures of 36, 34, and 32 degrees C the predicted mortality was 15%, 49%, and 84%, respectively. The authors conclude that hypothermia is a strong independent contributor to mortality in patients with ruptured abdominal aortic aneurysms and that very aggressive measures to prevent hypothermia are warranted during the resuscitation and treatment of these patients.

Aged↗

PubMedDate not supplied

Gastrointestinal complications following infrarenal endovascular aneurysm repair.

Gastrointestinal complications are known to occur after open elective aortic aneurysm repair. This leads to increased morbidity, mortality, length of stay, and hospital costs. The authors hypothesize a change in the character and/or frequency of early postoperative gastrointestinal complications after endovascular aneurysm repair as compared to open abdominal aortic repair. This is a retrospective cohort study in which the medical records of 153 consecutive patients who underwent endovascular infrarenal aneurysm repair from November 1998 to August 2001 were reviewed for gastrointestinal complications. Of these 153 patients, 9 (5.9%) had postoperative gastrointestinal complications. Three patients (1.9%) underwent exploratory laparotomy for small bowel obstruction. One patient had had a right hemicolectomy for cancer 2 years before stent graft placement. This patient needed a partial small bowel resection. One patient had had a right hemicolectomy 4 months before stent graft placement; he had lysis of adhesions with no bowel resection. A third patient underwent operative repair of an incarcerated inguinal hernia. Six patients (3.9%) had paralytic ileus that was treated by nasogastric tube or observation resulting in an extended hospital length of stay. All cases of ileus resolved without any operative intervention. No patients in this series developed any intestinal ischemia, pancreatitis, cholecystitis, or gastrointestinal bleeding. After endovascular aneurysm repair, gastrointestinal complications such as ileus and postoperative small bowel obstruction are seen with a similar frequency as after open aortic repair. This occurs despite the absence of a laparotomy with mesenteric dissection and evisceration. In this series, these complications are associated with longer hospital length of stay but no increased mortality rate. No instances of colonic ischemia, pancreatitis, cholecystitis, or gastrointestinal bleeding were seen in this series.

Aged↗

PubMedDate not supplied

Duplex ultrasound recognition of spontaneous carotid dissection--a case report and review of the literature.

Spontaneous dissection of the internal carotid artery is an uncommon entity with a variable clinical presentation. A high index of suspicion is required to make the diagnosis, and prompt diagnosis and treatment with anticoagulation are essential for improved patient outcomes. Duplex ultrasound provides a safe and reliable imaging modality for early diagnosis and follow-up. The authors present a case of spontaneous internal carotid artery dissection with duplex ultrasound findings and a review of the literature.

Anticoagulants↗

PubMedDate not supplied

Diagnosis of total internal carotid occlusions with duplex ultrasound and ultrasound contrast.

It remains a significant technical challenge for duplex ultrasound to accurately differentiate between total and near total internal carotid artery (ICA) occlusions. We have evaluated the efficacy of an ultrasound contrast agent combined with improved imaging techniques in patients with suspected carotid artery occlusions. Patients identified by conventional duplex ultrasound between January and August 2003 as having a possible ICA occlusion were eligible for study. A 1 mL bolus of ultrasound contrast agent was injected into a 50 mL bag of normal saline and given intravenously at a rate of approximately 4-5 mL/minute. Ultrasound imaging and spectral Doppler analysis were done using tissue harmonic imaging for optimum contrast agent to soft tissue discrimination, or with the direct B-mode imaging of blood flow to maximize the brightness of the circulating contrast agent. Ten patients were identified, 6 men and four women with a mean age of 68.3 years. Nine suspected total ICA occlusions were unilateral and 1 was bilateral. Imaging with contrast agent confirmed occlusion of the ICA in 7 of 10 patients; 3 patients had near-total occlusion with flow detected in the distal ICA by spectral and color Doppler. All 3 of these near-total occlusions were ultimately confirmed by either conventional or magnetic resonance carotid angiography. The contrast agent was most beneficial in improving the detection of minimal flow beyond a severe stenosis and in evaluating flow dynamics in the presence of severely calcified plaque. We conclude that the use of an ultrasound contrast agent with newer duplex ultrasound imaging techniques can reliably distinguish total from near-total internal carotid artery occlusions. Future prospective studies should be able to define the efficacy of ultrasound contrast agents in improving the overall diagnostic accuracy of duplex ultrasound in technically difficult cases and in patients with complex peripheral vascular disease.

Adult↗