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Biomedical subjects

C W Acher

Publications and source records attributed to C W Acher.

At least 37 records · Page 2Linked to original sources
PubMed1994

Combined use of cerebral spinal fluid drainage and naloxone reduces the risk of paraplegia in thoracoabdominal aneurysm repair.

PURPOSE: This report summarizes our experience with the use of cerebral spinal fluid drainage (CSFD) and naloxone for prevention of postoperative neurologic deficit (paraplegia or paraparesis). METHODS: We reviewed 110 consecutive patients with 86 thoracoabdominal aneurysms and 24 thoracic aneurysms. The status of 47 patients (43%) was acute (rupture or dissection), and the status of 52 (47%) was Crawford type I or II. None of the patients had intercostal artery reimplantation. There were two patient groups for analysis of neurologic deficit risk. Group A (61 patients) received naloxone and CSFD, and group B (49 patients) did not. RESULTS: One deficit occurred in group A and 11 deficits occurred in group B (p = 0.001). By multiple logistic regression analysis, the variables acute status, Crawford type II, or group B classification were significant factors for deficit risk. Use of the same logistic regression analysis on the subgroup of 47 patients with acute aneurysms and 33 patients with Crawford type 2 aneurysms confirmed the protective effect of combined CSFD and naloxone (group A) and that clinical presentation and extent of aorta replaced are the primary risk factors for development of deficit. To test this conclusion we developed a highly predictive model (correlation coefficient 0.997 with 16 series of thoracoabdominal aneurysms) for neurologic deficit. We applied our data to this model. Group B had the predicted number of deficits, and group A had substantially fewer deficits than predicted. CONCLUSIONS: We conclude that the combined use of CSFD and naloxone offers significant protection from neurologic deficits in patients undergoing thoracoabdominal and thoracic aortic replacement.

Adolescent↗
PubMed1994

Thrombolysis versus surgery as the initial management for native artery occlusion: efficacy, safety, and cost.

BACKGROUND: A controversy has evolved as to which therapy, thrombolysis or thromboembolectomy, represents the optimal initial treatment for acute native artery occlusion. METHODS: Forty-eight cases of acute class I or II limb ischemia caused by native artery occlusion were retrospectively analyzed between 1988 and 1993. Nineteen of the patients were initially treated with thrombolysis (group 1), and 29 underwent thromboembolectomy (group 2). RESULTS: Initial clinical improvement was seen in 11 (57.9%) of 19 extremities in group 1, with complete clot resolution in 21%, partial lysis in 47.4%, and no angiographic improvement in 31.6%. Significantly superior results were achieved in group 2; 28 (97%) of 29 limbs showed clinical improvement after initial surgical therapy (p = 0.001). Limb salvage was 88.2% in group 1 and 96.6% in group 2 (p = 0.5). Adjunctive procedures for limb salvage were necessary in 10 (52.6%) of 19 limbs in group 1 compared with only five (17.2%) of 29 limbs in group 2 (p = 0.013). Perioperative mortality was 10.5% and 10.3% (p = 1.0), whereas major postoperative complications occurred in 63.2% and 37% of patients in groups 1 and 2, respectively (p = 0.14). Hospital and professional patient charges were analyzed for the 12 most recent patients from each group. Total mean charges per patient were higher in group 1 ($45,171) than in group 2 ($24,898) (p = 0.046). CONCLUSIONS: Patients initially treated surgically achieved better immediate clinical results with significant cost savings and without significant differences in morbidity, mortality, or limb salvage compared with patients treated initially by thrombolysis.

Acute Disease↗
PubMed1993

Combined use of duplex imaging and magnetic resonance angiography for evaluation of patients with symptomatic ipsilateral high-grade carotid stenosis.

PURPOSE: Advances in cerebral vascular imaging suggest that patients with critical levels of carotid artery stenosis (> 70%) who have symptoms can be identified accurately and necessary information about the intracranial and extracranial circulation obtained before surgery without conventional angiography. We have used carotid duplex imaging in combination with magnetic resonance angiography (MRA) to evaluate 20 patients with symptomatic ipsilateral high-grade carotid stenosis. METHODS: All patients underwent CT and magnetic resonance imaging brain scans, as well as MRA and conventional arteriography of the cerebral circulation. Magnetic resonance angiograms were obtained with two-dimensional phase contrast and time-of-flight techniques. Phase contrast was used for intracranial vascular imaging and for determining qualitative flow velocities and the direction of blood flow in the circle of Willis. Two-dimensional time of flight was used to assess the carotid bifurcations. RESULTS: Twenty patients with symptoms (six with strokes, 11 with transient ischemic attacks, and three with amaurosis fugax) had duplex evidence of high-grade carotid stenoses. Computed tomographic and magnetic resonance brain scans were positive for cerebral infarction in six patients with clinical strokes. Comparison of MRA with conventional angiography was 91% accurate for high-grade stenoses and occlusions (sensitivity 100% and specificity 90% for stenosis; sensitivity/specificity was 100% for complete occlusion). Comparison of duplex imaging with conventional angiography demonstrated 86% accuracy for detection of severe stenosis or occlusion (sensitivity 94% and specificity 89% for stenosis; sensitivity and specificity were 100% for complete occlusion). CONCLUSIONS: This study suggests that combined use of MRA and duplex imaging is accurate for detection and evaluation of high-grade carotid stenoses in patients with symptoms.

Brain↗
PubMed1993

Magnetic resonance angiography and duplex imaging: noninvasive tests for selecting symptomatic carotid endarterectomy candidates.

BACKGROUND: This report describes our experience with the use of duplex imaging and magnetic resonance angiography (MRA) in the diagnosis and management of 70 patients with symptomatic carotid artery disease. Prospective evaluation of our first 30 patients showed that duplex imaging and MRA accurately correlated with conventional cerebral arteriograms (XRA) in patients with symptoms with greater than 70% ipsilateral carotid artery stenoses. In MRA versus XRA accuracy was 94%, sensitivity 100%, and specificity 93%. With duplex scanning versus XRA accuracy was 88%, sensitivity 93%, and specificity 93%. METHODS: We are now performing carotid endarterectomy on patients with symptoms without preoperative XRA when there is exact correlation between duplex imaging and MRA. Patients must have focal hemispheric symptoms, ipsilateral duplex peak systolic velocity greater than 2 m/sec, and high-quality MRA imaging of the carotid vessels. RESULTS: We have prospectively entered 40 patients for preoperative evaluation with duplex imaging and MRA. High-quality MRA and duplex studies were obtained in 35 patients (88%). XRA was required in the remaining five patients (12%) because of discrepancies between duplex scanning and MRA. Endarterectomy was performed without morbidity or death. Combined use of duplex scanning and MRA eliminated XRA in 35 cases and created a net savings of more than $125,000. CONCLUSIONS: Our experience suggests that preoperative XRA may not be necessary when duplex imaging and MRA confirm the presence of severe extracranial disease.

Carotid Arteries↗
PubMed1993

Crack and aortic dissection.

Aortic dissection represents a medical and, potentially, surgical emergency. Hypertension and cystic degeneration of the media are predisposing risk factors in the pathogenesis. Sporadic reports of aortic dissection in association with drug abuse especially crack cocaine are now appearing. We present such a patient whom we recently treated at University of Wisconsin Hospital.

Adult↗
PubMed1992

Comparative study of cefazolin, cefamandole, and vancomycin for surgical prophylaxis in cardiac and vascular operations. A double-blind randomized trial.

Three-hundred twenty-one adults undergoing cardiac or major vascular operations were randomized to receive intravenous cefazolin, cefamandole, or vancomycin for prophylaxis against surgical infection in a double-blind trial. All three regimens provided therapeutic blood levels throughout operation in patients studied undergoing cardiopulmonary bypass. The prevalence of surgical wound infection was lowest with vancomycin (4 infections [3.7%] versus 14 [12.3%] and 13 [11.5%] in the cefazolin and cefamandole groups, respectively; p = 0.05); there were no thoracic wound infections in cardiac operations in the vancomycin group (p = 0.04). The mean duration of postoperative hospitalization was lowest in the vancomycin group (10.1 days; p < 0.01) and highest in the cefazolin group (12.9 days). Prophylaxis with vancomycin or cefamandole, compared with cefazolin, did not prevent nosocomial cutaneous colonization by methicillin-resistant coagulase-negative staphylococci; colonization or infection with vancomycin-resistant staphylococci or enterococci was not detected. Adverse effects attributable to the prophylactic regimen were infrequent in all three groups. Eight patients given vancomycin became hypotensive during administration of a dose, despite infusion during a 1-hour period; however, slowing the rate of administration and pretreating with diphenhydramine allowed vancomycin to be resumed and prophylaxis completed uneventfully in five of the patients. We conclude that administration of vancomycin (approximately 15 mg/kg), immediately preoperatively, provides therapeutic blood levels for surgical prophylaxis throughout most cardiac and vascular operations, resulting in protection against postoperative infection superior to that obtained with cefazolin or cefamandole. Vancomycin deserves consideration for inclusion in the prophylactic regimen (1) for prosthetic valve replacement and prosthetic vascular graft implantation, to reduce the risk of implant infection by methicillin-resistant coagulase-negative staphylococci and enterococci; (2) for any cardiovascular operation if the patient has recently received broad-spectrum antimicrobial therapy; and (3) for all cardiovascular operations in centers with a high prevalence of surgical infection with methicillin-resistant staphylococci or enterococci. Guidelines for dosing and administration of vancomycin for cardiovascular surgical prophylaxis are provided.

Adult↗
PubMed1990

Lower extremity percutaneous transluminal angioplasty: multifactorial analysis of morbidity and mortality.

We analyzed the outcome of 202 percutaneous transluminal angioplasty (PTA) procedures performed between 1983 and 1989 to quantitate procedural risks and define factors associated with suboptimal results or immediate clinical failure. Premorbid factors studied included age, sex, treatment of single versus multiple lesions, stenoses versus occlusions, premorbid status of the limb (claudication vs limb threat), and most distal level of PTA. Adverse outcomes included complications (hematoma, acute occlusion, or thrombosis of PTA site, distal embolization, failure to dilate or cross, arterial dissection, rupture, and significant systemic derangement), major amputations (below knee and above knee), and deaths. There were 66 complications (32.7%), 22 amputations (10.9%), and 12 deaths (5.9%) in our series. Logistic regression analysis revealed that the major predictive variable for the occurrence of a complication (p = 0.002), and the only predictive variable for the outcomes of amputation and death (p = 0.0001 and p = 0.0139, respectively), was the premorbid clinical status of the limb. Lower extremity PTA is not an intrinsically benign procedure and is associated with a significant risk of complication, amputation, and procedure-associated death. These adverse outcomes cluster in patients with limb threat. Therefore it may be reasonable to restrict the use of PTA to patients with claudication and strictly selected cases of limb threat.

Adult↗
PubMed1990

Ruptured renal artery aneurysm in a pregnant uninephric patient: successful ex vivo repair and autotransplantation.

Renal artery aneurysm rupture during pregnancy is a rare event, with only 22 cases recorded in the literature. Maternal and fetal mortality rates have been high, and renal salvage with in situ repair of the renal artery has been documented in only three cases. We present here a case report of renal artery aneurysm rupture in a pregnant patient with congenital absence of the contralateral kidney, which was treated successfully with ex vivo renal artery reconstruction and autotransplantation. The literature on renal artery aneurysm rupture in pregnancy is reviewed and technical aspects of renal artery reconstruction and autotransplantation are presented.

Adolescent↗
PubMed1990

Naloxone and spinal fluid drainage as adjuncts in the surgical treatment of thoracoabdominal and thoracic aneurysms.

Forty-seven patients who were treated for thoracoabdominal or thoracic aneurysms over a 5 1/2-year period were analyzed for neurologic deficit risk. Patients were divided into two groups for analysis. Twenty-four patients, who were treated from January 1984 to December 1986, did not undergo spinal fluid drainage or naloxone administration (group A). Twenty-three patients, who were treated from January 1987 to August 1989, had spinal fluid drainage (group B); 12 patients in this group also received naloxone as an intravenous drip at 1 microgram/kg/hr for 48 hours after surgery. Permanent neurologic deficits occurred in seven (29%) group A patients but in only one (4%) group B patient, who did not receive naloxone (p less than 0.03). The first two group B patients to receive naloxone showed complete reversal of neurologic deficits on waking from anesthesia. This significant reduction in neurologic deficit was associated with an increased 1-year survival rate (72% in group A, 91% in group B). We conclude that the use of naloxone and spinal fluid drainage reduces the incidence of neurologic deficit that is associated with repair of thoracoabdominal and thoracic aortic aneurysms. This reduction in neurologic deficit is associated with improved survival in the long term. The observed reversal of postoperative neurologic deficits with naloxone implicates opiates as a major factor in the pathophysiology of spinal cord ischemia.

Adult↗
PubMed1989

Rotational muscle flaps: a new technique for covering infected vascular grafts.

Twenty-one patients with established localized infection of vascular bypass grafts were treated with aggressive debridement and rotational muscle flap coverage to control graft infection. There were six gram-positive, six gram-negative, four mixed, and three fungal graft infections. Graft material included Dacron, Gore-Tex (registered trademark of W. L. Gore Associates Inc., Elkton, Md.), Dacron and Gore-Tex in combination, and saphenous vein. Twenty of 21 patients had successful preservation of graft function, local wound healing, and control of infection. There were no amputations or deaths. The one failure was caused by incomplete debridement of an infected graft segment. Aggressive debridement and rotational muscle flap coverage is an effective means of treating locally infected vascular bypass grafts.

Adult↗
PubMed1989

Coverage of acute vascular injuries of the axilla and groin with transposition muscle flaps: case reports.

Acute axillary or groin vascular injuries caused by farm machinery or shotgun blasts are often associated with extensive soft-tissue loss. Coverage of the repaired blood vessels with healthy tissue is necessary to avoid infection, desiccation, pseudoaneurysm, and rupture. Adjacent muscles are not always available to rotate for coverage, due to unacceptable functional loss, or injury to the principal vascular pedicle. We used proximally based trunk musculature with vascular pedicles out of the areas of injury to achieve coverage of four extensive axillary wounds and one extensive groin wound. Arterial repair only was performed in three axillary wounds. Combined arterial and venous repair were performed in one groin wound and one axillary wound. Followup ranging from 9 months to 5 years revealed no vascular failure or soft-tissue complications. We conclude that coverage of vascular repairs and soft-tissue defects with viable muscle is necessary in cases of extensive injury. Adjacent muscle is preferred for coverage, but when this is unavailable, coverage can still be achieved using more proximally pedicled muscles of the trunk.

Adolescent↗
PubMed1989

Phlegmasia cerulea dolens and its association with hypercoagulable states: case reports.

Six patients who developed phlegmasia cerulea dolens are described. All patients had associated hypercoagulable states: heparin-induced thrombocytopenia (2 patients), congenital deficiency of protein C (1 patient), and antithrombin III deficiency (3 patients). Their clinical course and management are discussed. Previous reports have failed to show a definite correlation between phlegmasia cerulea dolens and hypercoagulable states because of an unavailability of appropriate diagnostic techniques. Phlegmasia cerulea dolens is a life- and limb-threatening complication. An appreciation of underlying hypercoagulable states is essential to proper management, prophylaxis, and treatment of this disorder.

Adult↗
PubMed1986

Percutaneous aspiration thromboembolectomy (PAT): an alternative to surgical balloon techniques for clot retrieval.

Percutaneous aspiration thromboembolectomy (PAT) is an angiographic technique that can be used to remove thromboembolic debris from the distal lower extremity circulation. This procedure employs a specially designed catheter-sheath system, which can be used alone or in combination with balloon angioplasty or thrombolytic drugs (streptokinase 10,000 U/hr or urokinase 100,000 U/hr for 6 hours) to remove thromboembolic material. PAT is best suited for treating iatrogenic emboli resulting from intra-arterial catheterization or balloon angioplasty but can be used as a supplement to Fogarty embolectomy when retained distal clot cannot be retrieved by surgical means and for removal of primary distal emboli of peripheral vascular or cardiac origin. PAT was used in 42 patients with acute threatening limb ischemia. Successful clot retrieval and limb salvage were achieved in 40 of the 42 patients (95%). The major complication was groin hematoma (7 of 42 patients, 17%) and one death occurred as a result of myocardial infarction (2.4%). PAT enhances the therapeutic role of angiography and can be used as an alternative to surgical embolectomy in selected patients.

Aged↗
PubMed1986

The diagnostic interface between noninvasive cerebral vascular testing and digital arteriography.

Two hundred forty patients with signs and symptoms of cerebrovascular disease were evaluated by digital and/or standard arteriography. One hundred twenty symptomatic patients had intravenous digital arteriography (IVDSA) done as the initial diagnostic study. Twenty-five percent (30 patients) had inadequate intravenous examinations and required additional intra-arterial studies. Twenty-seven of the 30 supplemental arteriograms (90%) demonstrated clinically significant disease. The remaining 120 patients (30 asymptomatic, 90 symptomatic) had preangiographic screening with continuous-wave Doppler and spectral analysis. Forty-eight (40%) patients had hemodynamically severe lesions and 72 (60%) had moderate stenosis or arterial wall disease. IVDSA was performed when critical disease was present and intra-arterial arteriography (80% digital and 20% standard) was done when mild or moderate disease was found. The use of digital techniques on the basis of results of preangiographic noninvasive testing improved the diagnostic accuracy of IVDSA and reduced the incidence of inadequate studies to 6%. Intra-arterial digital angiography (IADSA) was advantageous in reducing costs and patient risks when IVDSA was inappropriate.

Angiography↗
PubMed1985

Postoperative surveillance. An effective means of detecting correctable lesions that threaten graft patency.

Thirteen patients with recurrent ischemia following previous vascular surgery and 13 patients with primary ischemia were prospectively evaluated with segmental Doppler pressure indices and selective intravenous digital subtraction angiography. Ten patients with recurrent postoperative ischemia had thrombosed bypasses, and three had stenosed but patent grafts. Eight (62%) of the 13 patients had successful vascular repair, the rest had amputations. All patients with previous vascular surgery and those with primary bypasses were prospectively followed up with segmental Doppler pressure indices. Falling segmental Doppler pressure index values occurred in eight patients and in six patients prior to onset of recurrent ischemia. Intravenous digital subtraction angiography demonstrated correctable stenotic lesions in the six asymptomatic patients and untreatable host vessel occlusion in two symptomatic patients. Corrective surgery successfully preserved patency of all stenosed grafts. In summary, postoperative surveillance can detect occlusive changes before recurrent symptoms occur. Repair of stenosed grafts is more successful than repair of occluded grafts.

Angiography↗
PubMed1985

In situ distal saphenous vein bypass using the intraluminal valve-disruption technique.

In the last few years there has been a resurgence of interest in in situ saphenous vein bypass for lower extremity revascularization because of improved patency rates. We performed 28 in situ bypass operations in 26 patients with threatened limbs using the intraluminal Hall valve disrupter. Seventy-five percent of these bypasses were to tibial vessels and had a 93% early patency rate. Three late failures were salvaged before thrombosis of the bypass, resulting in a cumulative patency rate of 93% with a mean follow-up of 17 months. In situ saphenous vein bypass has become our procedure of choice for distal reconstruction in severely ischemic limbs because of improved long-term patency compared with reversed-saphenous vein bypass.

Adult↗