Biomedical subjects

Mark D Morasch

Publications and source records attributed to Mark D Morasch.

30 records · Page 2Linked to original sources

PubMed2004

Does carotid stenting measure up to endarterectomy? A vascular surgeon's experience.

HYPOTHESIS: Carotid angioplasty and stenting seems to have equal or better outcomes in high-risk patients than carotid endarterectomy. DESIGN: Single-center case-control study. SETTING: University hospital tertiary referral center. PATIENTS: Individuals (n = 53) undergoing elective carotid angioplasty and stenting for cervical carotid stenosis (n = 57) between April 2001 and October 2003. All patients were referred to and treated by the primary author (M.K.E.). RESULTS: Mean +/- SD age was 68.8 +/- 1.2 years (64% men [34] and 36% women [19]), and overall mean +/- SD rate of stenosis was 79% +/- 10%. Preprocedural neurologic symptoms were present in 42% of the group. Indications for treatment included prior neck surgery with irradiation (4), recurrent stenosis (19), and severe comorbidities (34). Duplex scanning 24 hours after stenting showed immediate mean percentage reductions in peaksystolic velocity and end diastolic velocity of 74% and 76%, respectively. After a 30-day follow-up period, there were no deaths and no major or minor strokes. One patient (1.7%) developed transient amaurosis fugax 12 hours after the procedure. Four patients (7.0%) experienced access-related complications. Intraoperative complications included 1 seizure (1.7%) and 1 asystolic arrest (1.7%), both treated successfully. During follow-up, 3 cases of re-stenosis (5.0%) occurred. One asymptomatic occlusion (1.7%) was detected at the 6-month follow-up visit. There have been no late carotid-related complications or deaths. CONCLUSIONS: Vascular surgeons possessing advanced catheter-based skills can safely perform carotid angioplasty and stenting and can achieve perioperative results comparable with carotid endarterectomy. Determination of the true efficacy and durability of carotid angioplasty and stenting as compared with endarterectomy awaits ongoing randomized national trials.

Aged↗

PubMed2004

Early results with use of gracilis muscle flap coverage of infected groin wounds after vascular surgery.

INTRODUCTION: Management of a nonhealing femoral wound after vascular surgery can pose a challenging problem, particularly when there is prosthetic material involved. We prefer to use pedicled gracilis muscle flaps (PGMFs) to cover problematic groin wounds when more conventional management is not possible. METHODS: We describe the technique for using PGMFs to provide groin coverage, report a summary of our short-term and long-term results, and describe why we prefer this reconstructive technique. RESULTS: Twenty PGMFs were placed in 18 patients to treat nonhealing and infected groin wounds. Exposed prosthetic vascular reconstructions were covered with the PGMF in 14 wounds, and in situ autogenous vascular reconstructions were covered in four. Seven wound infections were polymicrobial, 10 had a single gram-positive organism, and one had a single gram-negative organism. Pseudomonas cultured out in four wounds, and Candida in one wound. Two patients had a virulent combination of methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococcus. Complete healing was initially achieved in all wounds, and no patient died within 30 days of surgery. Two PGMFs failed, at 2 weeks and 2 months, respectively, one from tension on the flap pedicle and one from acute inflow occlusion. Underlying prosthetic reconstruction was salvaged in 12 of 14 wounds; the remaining wounds with autogenous reconstructions or exposed femoral vessels all closed successfully. At a mean follow-up of 40 +/- 10 months there were no recurrent groin infections. Seven patients died, at 2.5, 3, 8, 12, 14, 22, and 28 months, respectively. CONCLUSION: PGMF transposition is an effective option to cover infected or exposed femoral vessels or salvage prosthetic graft material in the groin. In appropriately selected patients, when complete graft removal and extra-anatomic bypass is not an acceptable option, gracilis muscle flap coverage is a viable alternative. The technique is relatively simple, and morbidity from PGMF harvest is minimal.

Adult↗

PubMed2004

Percutaneous repair of abdominal aortic aneurysm.

OBJECTIVE: Percutaneous treatment of an abdominal aortic aneurysm (AAA) is feasible, but is associated with a unique set of risks. A comparison of Excluder endograft deployment with femoral artery cutdown (FAC) versus percutaneous femoral access (PFA) for treatment of infrarenal AAA was undertaken. METHODS: A single-institution, controlled, retrospective review was carried out in patients who underwent either bilateral FAC or bilateral PFA for endovascular repair of infrarenal AAA with the Gore bifurcated Excluder endograft between March 1999 and November 2003. To November 2000, 35 patients underwent bilateral FAC; since then, 47 patients have undergone bilateral PFA. All have been followed up for at least 30 days. RESULTS: Mean AAA size was 5.7 cm in the FAC group and 6.0 cm in the PFA group. During hospitalization there were six access-related complications in the FAC group; three required early surgical intervention. In the PFA group nine perioperative access-related complications occurred, all consisting of either hemorrhage or arterial occlusion; seven required additional intervention, and were recognized and ameliorated while the patient was still in the operating room. At 30-day follow-up there were no additional access-related complications in the PFA group. There were eight other access-related complications in eight additional patients who underwent FAC. In patients undergoing bilateral PFA total operative time was shorter (PFA 139 minutes vs FAC 169 minutes; P =.002), total in-room anesthesia time was less (PFA 201 minutes vs FAC 225 minutes; P <.008), and use of general anesthesia was reduced (P <.001). No significant differences were observed between groups with respect to estimated blood loss (PFA 459 mL vs FAC 389 mL; P =.851). CONCLUSION: Complete percutaneous treatment of AAA may have some advantages over open femoral artery access, but it is not free from risk. Percutaneous treatment of AAA can be completed successfully in most patients, but should be performed at an institution where conversion to an open procedure can be completed expeditiously if necessary.

Aged↗

PubMed2003

Tumor embolus: a case report and review of the literature.

Peripheral embolization of macroscopic tumor fragments is an uncommon occurrence. A patient with a previously undiagnosed primary lung adenocarcinoma who presented with an acutely ischemic limb is described. Following review of the literature, the characteristics of tumor embolization are discussed.

Adenocarcinoma↗

PubMed2003

Inferior vena cava thrombus removal using hypothermic circulatory arrest in two patients with osteosarcoma.

In this case report, the technique of deep hypothermia and circulatory arrest (DHCA) is used to successfully extract extensive symptomatic tumor thrombus from the inferior vena cava (IVC) in two patients with osteosarcoma. This is the first description of the use of this modality for treatment of osteosarcoma involving the IVC. Osteosarcoma and the use of DHCA are discussed.

Adult↗

PubMed2003

Safety of gadolinium contrast angiography in patients with chronic renal insufficiency.

OBJECTIVE: To prevent iodinated contrast medium-induced nephrotoxicity, gadolinium has been used increasingly for magnetic resonance angiography (MRA) or conventional digital subtraction angiography (DSA) to visualize arterial anatomy in patients undergoing vascular surgery who are considered at high risk because of chronic renal insufficiency. We assessed the safety of gadolinium-based contrast medium as a substitute for iodinated contrast medium-enhanced examinations. We determined the incidence of gadolinium-induced nephrotoxicity in a clinical setting and searched for contributing risk factors. Patients and methods In a single-center retrospective study from December 1999 to January 2001, 218 inpatients underwent MRA and 42 inpatients underwent DSA, with gadolinium as the sole contrast agent. Patient comorbid conditions, indications for vascular imaging, contrast dose, urine output, baseline and post-procedure serum creatinine concentration (SCr), and outcome were recorded for all patients in whom gadolinium-induced renal failure developed. RESULTS: Of 260 patients who received gadolinium-based contrast agents, at a dose of 0.25 mmol/kg or more, 195 patients (75%) had pre-test baseline chronic renal insufficiency. In 7 of 195 patients (3.5%) acute renal failure developed after gadolinium-based contrast medium administration, for MRA (n = 153) in 3 patients (1.9%) and DSA (n = 42) in 4 patients (9.5%). Average baseline SCr in the 195 patients with chronic renal insufficiency was 38.2 +/- 1.6 mL/min/1.73 m(2), and in the 7 patients in whom acute renal failure developed, baseline SCr was 32.5 +/- 7.8 mL/min/1.73 m(2) (P =.33). Respective intravenous and intra-arterial gadolinium doses in these 7 patients ranged from 0.31 to 0.41 mmol/kg for MRA and 0.27 to 0.42 mmol/kg for DSA. Acute renal failure did not develop in any of 65 patients with normal baseline SCr. CONCLUSION: Despite reports of negligible nephrotoxicity, rarely gadolinium-based contrast agents can cause acute renal failure in patients with underlying chronic renal insufficiency. Estimation of creatinine clearance alone does not enable prediction of which patients are likely to have acute renal failure. Patients at high-risk should be identified, and prophylactic measures should be taken to reduce the risk for nephrotoxicity.

Acute Kidney Injury↗

PubMed2003

Fate of excluded popliteal artery aneurysms.

OBJECTIVE: Popliteal artery aneurysms (PAA) are frequently treated with ligation and exclusion bypass grafting. It is assumed that these aneurysms will shrink and remain asymptomatic. This may not always be true. We sought to elucidate the fate of excluded PAA over time. METHODS: Data for all PAAs treated with ligation and exclusion bypass grafting between 1986 and 1999 were retrospectively reviewed. Computed tomography (CT) scans and duplex ultrasound scans provided aneurysm patency data and maximal transverse diameter measurements of the popliteal artery during late postoperative follow-up. This information was compared with that from similar preoperative studies. RESULTS: Forty-one patients (39 men, 2 women) underwent 57 ligation and exclusion bypass grafting procedures. Both preoperative and late postoperative (mean, 4.0 years; range, 0.43-13.5 years) CT scans or duplex ultrasound scans were available for review of 25 PAAs in 18 patients (ages 42-80 years; mean, 63 years). Preoperative PAA size ranged from 14 to 45 mm (mean, 28.7 mm). In late follow-up, 12 (48%) PAA had decreased in size (mean, 7.3 mm), 5 (20%) remained unchanged, and 8 (32%) increased in mean transverse diameter (mean, 5.9 mm). One large aneurysm increased by 50%. Contrast material enhancement was identified in the excluded sac in 11 aneurysms. CONCLUSIONS: PAA treated with ligation and exclusion bypass grafting often expand and can become symptomatic. This may be analogous to type II endoleak or endotension noted after aortic endovascular repair. We recommend PAA excision or endoaneurysmorrhaphy when feasible.

Adult↗

PubMed2003

Lower extremity stepping-table magnetic resonance angiography with multilevel contrast timing and segmented contrast infusion.

OBJECTIVES: Standard lower extremity contrast-enhanced magnetic resonance angiography (LE-CEMRA) with single injection bolus-chase methods on the basis of a single pelvis timing run can be accurate for depicting most vascular occlusive lesions but may fall short of catheter-based angiography when imaging tibial and pedal vessels. Magnetic resonance angiography techniques with a second contrast timing bolus and separate acquisitions for the calves and the pelvis greatly improve reliability and reduce venous contamination to levels that may render conventional angiography obsolete. METHODS: From July to December 2001, 60 consecutive patients underwent LE-CEMRA of the calves with separate stepping-table acquisitions of the pelvis and thighs. Forty-five (75%) had complete or partial angiographic correlation during an endoluminal intervention or operative completion study. Lower extremity vessels were divided into anatomic segments (aortoiliac, femoropopliteal, tibial-pedal) for review. Three blinded observers assessed magnetic resonance source partitions, maximum-intensity projections, and volume-rendered images. Disease per segment was graded from insignificant (<20%) to occluded (100%) in 10% increments. Segments were also scored for venous contamination (scale, 0 to 3) and diagnostic quality (scale, 1 to 5). Digital subtraction angiograms were assessed similarly but separately. RESULTS: The combination dual-timing/dual-injection technique had an overall sensitivity, specificity, and accuracy of 99%, 97%, and 98%. Venous contamination and artifact were virtually eliminated with combined technique LE-CEMRA. Diagnostic quality of calf and foot vessels was significantly superior to conventional bolus-chase magnetic resonance techniques (P <.01). CONCLUSION: Hybrid dual-acquisition LE-CEMRA allows complete timing specification that consistently produces high-quality, artifact-free images of the calf and pedal vessels. These techniques may be accurate enough to replace conventional digital subtraction angiogram for evaluation of lower extremity vascular occlusive disease.

Adult↗

PubMed2002

Cross-sectional magnetic resonance angiography is accurate in predicting degree of carotid stenosis.

Carotid stenosis is currently estimated using methods based on flow velocity or two-dimensional projection images. Manipulation of magnetic resonance (MR) images in three dimensions (3-D MR) allows for direct measurement of carotid artery cross-sectional luminal area. The objectives of this study were (1) to assess the accuracy of 3-DMR as a technique for estimating carotid artery stenosis, and (2) to compare 3-D MR results with estimates from duplex ultrasound sonography (DUS) and conventional angiography. Twenty-nine patients underwent rapid, contrast-enhanced MRA within 1 month prior to carotid endarterectomy to obtain 3-D angiographic images of the carotid bifurcation. From these data, post-processing software was used to generate a longitudinal axis through the center of the vessel along which orthogonal cross-sectional images were taken. Luminal area measurements at the location of tightest stenosis and the distal normal internal carotid artery were obtained and used to calculate percent area stenosis. Applying the same procedure, 18 en bloc, ex vivo carotid plaques served as the standard against which we compared in vivo 3-D MR measurements at the location of tightest stenosis. Percent stenosis comparisons between MRA, angiography, and duplex ultrasound were also made. Our results showed that the measurement of luminal area by 3-DMR is accurate in predicting the degree of carotid stenosis. Direct measurement of luminal area may overcome limitations inherent to methods that rely on flow velocities and two-dimensional views of the carotid vasculature. A larger prospective study is necessary to confirm the reliability of this technique.

Carotid Stenosis↗

PubMed2002

Caudal migration of endoprostheses after treatment of abdominal aortic aneurysms.

BACKGROUND: The purpose of this study is to assess the migration of endoprostheses 2 years after endovascular abdominal aortic aneurysm repair. METHODS: Ten patients underwent placement of bifurcated endoprostheses for infrarenal aneurysm and had 2-year CT follow-up. Standardized contrast-enhanced CT with 1.5- or 2-mm overlapping slice thickness was used. Four independent observers measured the distance from the lowest renal artery to the craniad end of the graft. RESULTS: As a whole, the endoprostheses migrated an average of 2.7 +/- 2.6 mm caudad at 24 months compared with baseline (P < 0.001). Four patients (40%) experienced > or =3-mm migration of the endoprostheses. On review of the 6- and 12-month follow-up CT scans, movement occurred at both the first- and the second-year intervals. CONCLUSIONS: Endovascular stent-grafts frequently migrate away from the renal arteries. This may be due to natural elongation of the native infrarenal aortic segment, but could also result from inadequate attachment of the proximal stent-graft. Although there have been no adverse clinical events in this group, continued close follow-up is mandatory following endovascular aneurysm repair.

Aged↗

PubMed2002

Abdominal aortic reconstruction in infected fields: early results of the United States cryopreserved aortic allograft registry.

OBJECTIVE: Aortic reconstructions for primary graft infection (PGI), mycotic aneurysm (MA), and aortic graft-enteric erosion (AEE) bear high morbidity and mortality rates, and current treatment options are not ideal. Cryopreserved grafts have been implanted successfully in infected fields and may be suitable for abdominal aortic reconstructions. Registry data from several institutions were compiled to examine results of cryopreserved aortic allograft (CAA) placement. METHODS: The experience of 31 institutions was reviewed for CAAs inserted from March 4, 1999, to August 23, 2001. Indications for CAA, organisms, mortality, and complications were identified. RESULTS: Fifty-six patients, 43 men and 13 women, with a mean age of 66 years (range, 44 to 90 years) had in situ aortic replacement with CAA. Indications for CAA placement were PGI in 43 patients (77%), MA in seven (14%), AEE in four (7%), and aortic reconstruction with concomitant bowel resection in two (4%). Infectious organisms were identified in 33 patients (59%); the most frequent organism was Staphylococcus aureus in 17 (52%). Thirty-one patients (55%) needed an additional cryopreserved segment for reconstruction. The mean follow-up period was 5.3 months (range, 1 to 22 months). One patient died in the operating room, and the 30-day surgical mortality rate was 13% (7/56). Seven additional patients died during the follow-up period, yielding an overall mortality rate of 25% (14 patients). Two patients (4%) had graft-related mortality as the result of hemorrhage from the CAA and persistent infection. Graft-related complications included persistent infection with perianastomotic hemorrhage in five patients (9%), graft limb occlusion in five (9%), and pseudoaneurysm in one (2%). Three patients (5%) needed amputation. CONCLUSION: In situ aortic reconstruction with CAA in infected fields carries a high mortality rate, but most deaths are not the result of allograft failure. However, CAA infection and lethal hemorrhage caused by graft rupture occurs and is concerning. Early reinfection was not reported. Late graft-related complications, such as reinfection, thrombosis, or aneurysmal changes, are unknown. Preliminary data from this registry fail to justify the preferential use of CAA for PGI, MA, or AEE. A multicenter, randomized study is needed to compare results with established techniques.

Adult↗

PubMedDate not supplied

Abdominal wall hernias after open abdominal aortic aneurysm repair: prospective radiographic detection and clinical implications.

The purpose of this study was to evaluate the prevalence of radiographically detected abdominal wall defects (AWD) after open abdominal aortic aneurysm (AAA) repair and to correlate it with prospectively gathered clinical information. Fine collimation, high-resolution, serial follow-up computed tomography (CT) scans for 99 patients in the control group of the Guidant Ancure device trial were reviewed. CT scans were obtained at 12, 24, 36, 48, and 60 months. AWDs, defined as discontinuity of the fascial layer with protrusion of abdominal contents, were identified. Clinical information regarding AWDs was retrieved from the study registry. The prevalence of AWD exceeds 20% and plateaus at 24 months. Eight patients (8%) had clinical evidence of ventral incisional hernias. One patient underwent repair, but no other patient developed hernia incarceration or intestinal obstruction or required additional procedures related to the AWD. AWDs are radiographic findings occurring frequently after open AAA repair. Radiographic evaluation is more sensitive than clinical observation for detection of ventral hernias. Clinical events and reinterventions related to these radiographic abnormalities are rare.

Aortic Aneurysm, Abdominal↗