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Bower, Thomas C.

Mayo Clinic

Mayo Clinic

Citations 28

Motor and Somatosensory Evoked Potentials
Shine, Timothy, Harrison, Barry, Ruyter, Martin L. De, Daube, Jasper R., Stapelfeldt, Wolf H. , Cherry, Kenneth J., Gloviczki, Péter , Bower, Thomas C., Crook, Julia E. , Heckman, Michael G. , Murray, Michael J. , Gloviczki, Péter

Anesthesiology | March 5, 2009 | Volume: 108 | Issue: 4 | Pages: 580-587

10.1097/aln.0b013e318168d921 Get It

Background Paraplegia is a devastating complication for patients undergoing repair of thoracoabdominal aortic aneurysms. A monitor to detect spinal cord ischemia is necessary if anesthesiologists are to intervene to protect the spinal cord during aortic aneurysm clamping. Methods The medical records of 60 patients who underwent thoracoabdominal aortic aneurysm repair with regional lumbar epidural cooling with evoked potential monitoring were reviewed. The authors analyzed latency and amplitude of motor evoked potentials, somatosensory evoked potentials, and H reflexes before cooling and clamping, after cooling and before clamping, during clamping, and after release of aortic cross clamp. Results Twenty minutes after the aortic cross clamp was placed, motor evoked potentials had 88% sensitivity and 65% specificity in predicting spinal cord ischemia. The negative predictive value of motor evoked potentials at 20 min after aortic cross clamping was 96%. Conclusions Rapid loss of motor evoked potentials or H reflexes after application of the aortic cross clamp identifies a subgroup of patients who are at high risk of developing spinal cord ischemia and in whom aggressive anesthetic and surgical interventions may be justified.
Renal Artery Intervention in Pediatric and Adolescent Patients: A 20-Year Experience
Huang, Ying , Duncan, Audra A. , McKusick, Michael A., Milliner, Dawn S. , Bower, Thomas C., Kalra, Manju , Gloviczki, Péter , Hoskin, Tanya L. , Gloviczki, Péter

Vascular and Endovascular Surgery | January 7, 2008 | Volume: 41 | Issue: 6 | Pages: 490-499

10.1177/1538574407307944 Get It

Between 1986 and 2005, 22 patients (mean age, 14.7 years; range, 3-21) with renal hypertension underwent renal artery revascularization for 28 lesions, 23 with open repair (OR) and 5 with percutaneous transluminal renal angioplasty (PTRA). Thirty-day morbidity was 17% (4/23). Hypertension was cured in 13 (57%), improved in 8 (38%), and unchanged in 1 (5%). Renal function worsened in 1. At a mean follow-up of 4.9 years, 1-year patency rate was 94% and maintained for 5 years. Hypertension at 1 year was cured in 6 of 14 patients (43%; OR, 4; PTRA, 2) and improved in 8 (57%; OR, 7; PTRA, 1); hypertension at 5 years was cured in 50% and improved in 50%. Renal function remained unchanged in all patients who were followed. The authors conclude that both OR and PTRA benefit pediatric patients. PTRA for selected patients may be promising as a first line treatment or as a bridge to definitive OR in children with small arteries.
Laparotomy for Presumed Ruptured Abdominal Aortic Aneurysm: Outcome of Deceptive Emergencies
Melin, Matthew M , Gloviczki, Péter , Cherry, Kenneth J., Bower, Thomas C., Hallett, John W., Baerga, Yvonne, Zietlow, Scott P., Stanson, Anthony W., Gloviczki, Péter

Vascular Surgery | November 26, 2007 | Volume: 31 | Issue: 5 | Pages: 523-530

10.1177/153857449703100503 Get It

Medical and surgical emergencies occasionally present as ruptured abdominal aortic aneurysms (RAAA). To assess benefits of laparotomies and adverse effects of unnecessary operations, the authors reviewed their experience. Thirteen patients, 9 women, 4 men (mean age: 72 years, range: 41-85) underwent emergency laparotomy between 1988 and 1996 for presumed RAAA and were found to have other surgical or medical emergencies. All the patients presented with hypotension, 12 had abdominal or back pain, four had pulsatile abdominal mass. Rupture was not excluded by computed tomography scan in three or by ultrasonography in two patients. Laparotomy disclosed intact abdominal aorta in all, but seven patients had abdominal aortic aneurysm. Of five surgical emergencies, laparotomy was indicated in four: three for ruptured visceral artery aneurysms, one for perforated duodenal ulcer. The fifth patient required thoracotomy for ruptured thoracic aneurysm. Four of eight medical emergencies were myocardial infarctions. One iatro genic complication required reoperation for bleeding. Mean hospital stay was 18 days; mean hospital charges were $40,771. Seven (54%) early deaths occurred; none were caused directly by the operation. Laparotomy was indicated in one third of deceptive emergencies that present as RAAA. Although mortality, morbidity, and costs were high, iatrogenic surgical complica tions were rare and deaths were not caused by unnecessary operations.
The Case for Aggressive Treatment
Gloviczki, Péter , Canton, Linda G., Bower, Thomas C., Cherry, Kenneth J., Hallett, John W., Stanson, Anthony W., Pairolero, Peter C., Gloviczki, Péter

Vascular Surgery | November 26, 2007 | Volume: 31 | Issue: 3 | Pages: 319-320

10.1177/153857449703100343 Get It

Optimal Management of Abdominal Aortic Aneurysms and Urologic Malignancies: Benefits of Simultaneous Surgical Treatment
Noel, Audra A., Gloviczki, Péter , Cherry, Kenneth J., Bower, Thomas C., Hallett, John W., Panneton, Jean M. , Whitley, David, Blute, Michael L., Stanson, Anthony W., Gloviczki, Péter

Vascular Surgery | June 21, 2007 | Volume: 33 | Issue: 6 | Pages: 603-609

10.1177/153857449903300604 Get It

The coexistence of urologic malignancy (UM) and abdominal aortic aneurysm (AAA) is rare. Simultaneous treatment may increase morbidity, whereas staged operations delay necessary treatment. We reviewed our experience to develop guidelines for evaluation and management. Clinical data of all patients diagnosed between 1980 and 1998 with both AAA and UM, who also had staged or simultaneous surgical treatment were reviewed. Four thousand forty-seven patients underwent AAA repair during the study period at our institution. Of these, 18 (0.44%) patients, 16 men and two women (mean age: 74 years, range: 61 to 92) had UM. UM was discovered incidentally in nine patients with AAA with computed tomography (CT) scan (7) and ultrasonography (2). In one patient with AAA, hematuria raised the suspicion of UM. Eight patients were diagnosed with AAA during evaluation of UM by CT scan or ultrasound (7) or during laparotomy (1). Initial signs and symptoms included abdominal pain (33%), gross hematuria (33%), and urinary tract infections (17%), although 33% were asymptomatic. The AAA was symptomatic at first examination in three (17%) patients, 14 (78%) patients had hypertension, and two (11%) had renal insufficiency (overall mean serum creatinine: 1.6, range: 0.8 to 3.7). Mean AAA diameter was 5.8 cm (range: 3.8 to 8 cm). Aortography documented significant contralateral renal artery disease in two patients. Twelve patients underwent simultaneous AAA repair and resection of UM; the operations were staged in six (AAA repair first in 2, nephrectomy first in 4). One patient required emergent repair of a ruptured AAA three days after nephrectomy. UM was treated with nephrectomy in 17 patients, and with bilateral ureterectomy and cystectomy in one. A straight aortic graft was implanted in seven patients, a bifurcated graft in ten, and one had extra-anatomic reconstruction. Two patients required reconstruction of the contralateral renal artery. The 30-day mortality rate was 0% after staged and 6% after simultaneous repair (p= >0.1). Major perioperative complications occurred more frequently after simultaneous (42%) than after staged repair (33%), although the difference was not significant (p= >0.1). Two patients developed postoperative renal failure. Seventeen patients were followed for an average of 3.9 years (14 days to 10.8 years). Three (17%) patients died of recurrent cancer at 1, 10.7, and 10.8 years after surgery. Patients with resectable UM have satisfactory long-term survival, which justifies aggressive treatment of concomitant AAA. Aortography in these patients is suggested to exclude contralateral renal artery disease. Complications were frequent, but simultaneous repair did not increase morbidity or mortality significantly. The risk of AAA rupture after nephrectomy, need to correct contralateral renal artery disease at the time of nephrectomy, and disadvantage of delaying treatment of UM are compelling reasons to favor simultaneous treatment of AAA and UM.
Intraoperative Duplex Ultrasound During Carotid Endarterectomy
Panneton, Jean M. , Berger, Mark W., Lewis, Bradley, Hallett, John W., Bower, Thomas C., Gloviczki, Péter , Cherry, Kenneth J., Gloviczki, Péter

Vascular Surgery | June 21, 2007 | Volume: 35 | Issue: 1 | Pages: 1-9

10.1177/153857440103500102 Get It

The purpose of this study was to examine the technical aspects of intraoperative duplex ultrasound (DUS) following carotid endarterectomy (CEA), suggest criteria to differentiate significant lesions requiring immediate surgical revision from normal or benign defects, and evaluate how frequently intraoperative DUS provides useful or unsuspected information. A retrospective study was performed on all patients who had both CEA and intraoperative carotid DUS between January 1,1990. and January 1,1995. A total of 155 DUS examinations were performed in 149 patients. Findings were grouped into three categories: normal; minor/insignificant lesions; and hemodynamically significant lesions based on the presence or absence of elevated peak systolic velocities, visible stenosis/thrombus, or intimal flap/dissection. Postoperative status was correlated with intraoperative DUS findings. Ninety-one (59%) examinations performed on 87 patients produced normal findings. Forty-seven (30%) examinations performed on 45 patients showed minor abnormalities consisting of insignificant residual plaque, residual external carotid artery stenoses, small intimal flaps, elevated velocities with no associated anatomic lesion, or an arterial kink. Fourteen patients (9%) had significant findings requiring immediate surgical revision. These consisted of large intimal flaps or dissection in six patients, marked residual plaque and significant stenosis in five patients, thrombus in two patients, and a kink in one patient. Three additional patients ( 2 %) had significant findings but were not revised for various reasons. No significant difference was identified in morbidity or mortality rates between those patients with normal findings, those patients with minor technical defects, and those patients with significant abnormalities undergoing immediate surgical revision. However, two of three patients who had significant abnormalities within the common carotid artery that were not revised suffered perioperative ipsilateral strokes. Intraoperative DUS is a safe and accurate method to assess the technical adequacy of CEA. Intraoperative DUS showed significant lesions in 11% of patients. Identification and immediate repair of significant technical defects may decrease perioperative complication rate and long-term restenosis rate.
Most Patients with Abdominal Aortic Aneurysm Are Not Suitable for Endovascular Repair Using Currently Approved Bifurcated Stent-Grafts
Elkouri, Stéphane , Martelli, Eugenio , Gloviczki, Péter , McKusick, Michael A., Panneton, Jean M. , Andrews, James C. , Noel, Audra A., Bower, Thomas C., Sullivan, Timothy M. , Rowland, Charles M. , Cherry, Kenneth J., Hoskin, Tanya L. , Gloviczki, Péter

Vascular and Endovascular Surgery | March 31, 2006 | Volume: 38 | Issue: 5 | Pages: 401-412

10.1177/153857440403800502 Get It

Strict morphologic criteria must be used for patient selection to achieve durable success with endovascular aortic aneurysm repair (EVAR). The goal of this study was to assess morphologic suitability (MS) of abdominal aortic aneurysms (AAAs) for 2 currently approved bifurcated stent grafts and identify reasons for exclusion from EVAR. The authors reviewed the electronic charts of 1,795 consecutive patients who were diagnosed as having AAA between January 1999 and July 2001 at their institution. Three hundred and twenty patients had an AAA with a diameter of =5.0 cm, measured on computed tomography (CT). The records of 301 patients, 254 men, 47 women, with a mean age of 74 years were available for review, and these patients constituted the study cohort. Criteria used for MS included a proximal neck length =15 mm; neck diameter between 18 and 26 mm; neck angulation =60°; common or external iliac artery (CIA or EIA) diameters of 7–16 mm and 8–13 mm, respectively, for AneuRx (Medtronic Ave, Santa Rosa, CA) and Ancure (Guidant Cardiac and Vascular Division, Menlo Park, CA) bifurcated grafts. AAAs were suitable for AneuRx device in 14% of patients (43 of 301; 95% CI = 11–19%) and for Ancure in 5% (16 of 301; 95% CI = 3.1–9%). The main reason for exclusion was an inadequate proximal aortic neck (73%). The neck was too short in 49.5%, too wide in 64% and badly angulated in 12% of the patients. Iliac artery morphology precluded EVAR with AneuRx and Ancure devices in 52% and 80%. Both CIAs were too wide for EVAR in 43% and 77%, respectively. When iliac artery diameter =20 mm was accepted, iliac suitability for AneuRx increased from 49% to 70% and overall suitability increased from 14% to 20%. When more permissive criteria were used for MS (neck length =10 mm, neck diameter =30 mm, CIA =20), 39% of patients became candidates for EVAR. More than three fourths of the patients with an AAA =5.0 cm in size, seen in a tertiary referral center, are morphologically not suitable for EVAR using 2 currently approved bifurcated endografts. The main reasons for exclusion are a short or wide proximal aortic neck. Considerable changes in size of the devices and in proximal attachment techniques have to occur before most AAAs will be suitable for EVAR.
Renal Artery Stenosis and a Functioning Hilar Paraganglioma: A Rare Cause of Renovascular Hypertension
Chandra, V., Thompson, Geoffrey B. , Bower, Thomas C., Taler, Sandra J.

Vascular and Endovascular Surgery | March 31, 2006 | Volume: 38 | Issue: 4 | Pages: 385-390

10.1177/153857440403800413 Get It

Surgically correctable causes of hypertension are uncommon. Simultaneous occurrence of 2 such causes in the same individual is extremely rare. The authors describe a 25-year-old woman with congenital erythrocytosis, renal artery stenosis, and a paraganglioma. The possible mechanisms of renal artery stenosis in the presence of a catecholamine-secreting tumor are discussed.