Biomedical subjects

G C Hunter

Publications and source records attributed to G C Hunter.

At least 37 records · Page 2Linked to original sources

PubMed1997

Edgar J. Poth Memorial/W.L. Gore and Associates, Inc. Lectureship. The clinical and pathological spectrum of recurrent carotid stenosis.

BACKGROUND: Hemodynamically significant (> or =50%) carotid restenosis occurs in approximately 10% to 12% of individuals undergoing carotid endarterectomy. The underlying pathology is usually neointimal thickening within 3 years and recurrent atherosclerosis thereafter. Although a number of etiologic factors have been implicated in the development of restenosis, the etiology remains unclear and preventative measures relatively ineffective. METHODS: A review of the English literature was undertaken to determine the incidence, clinical presentation, and pathologic features of carotid restenosis. CONCLUSIONS: Carotid restenosis is the major factor limiting long-term patency after carotid endarterectomy. Although drug therapy has been shown to be effective in preventing restenosis in animal models, the results of clinical human trials have been disappointing. Delineation of the biochemical and molecular mechanisms contributing to the development of restenosis is essential if effective therapeutic interventions are to be developed.

Carotid Arteries↗

PubMed1997

Distal revascularization-interval ligation for limb salvage and maintenance of dialysis access in ischemic steal syndrome.

PURPOSE: Traditional options for treating ischemic steal syndrome related to a functioning dialysis access graft or fistula include banding or ligation. Unfortunately, these techniques usually result in inconsistent limb salvage, loss of a functional access, or both. We report our experience with an alternative method of limb revascularization that eliminates steal while maintaining continuous dialysis access. METHODS: Patients who had critical limb ischemia and functioning arteriovenous fistulae (AVF) underwent color-flow duplex scanning, digital photoplethysmography, and arteriography. Arterial ligation distal to the AVF origin eliminated the steal physiologic mechanism while arterial bypass grafting from above to below the AVF revascularized the extremity (distal revascularization-interval ligation [DRIL] procedure). RESULTS: From March 1994 through December 1996, 21 patients with functioning extremity AVFs presented with critical ischemia and steal syndrome. Eleven patients had chronic ischemia with rest pain, paresthesias, or ulcerations related to nine native fistulae (six brachiocephalic, two basilic vein transpositions, one radiocephalic) and two prosthetic bridge grafts (one upper arm, one lower extremity). Acute ischemia developed in 10 patients related to three native fistulae (two brachiocephalic, one radiocephalic) and seven prosthetic bridge grafts (three forearm, three lower extremity, one upper arm). All 21 patients were treated with the DRIL technique. Three of these patients required treatment for ischemia at the time of AVF construction. Nineteen of 21 bypass procedures were performed with autogenous vein, including nine brachial-brachial, three brachial-radial, two radial-radial, two brachial-ulnar, one popliteal-popliteal, one femoral-popliteal, and one femoral-peroneal. Polytetrafluoroethylene grafts were used for one external iliac-popliteal bypass graft and one axillary-brachial bypass graft. Limb salvage and maintenance of a functional fistula were achieved in 100% and 94%, respectively, at 18 months by life-table analysis. CONCLUSION: The DRIL technique reliably restores antegrade flow to the ischemic limb, eliminates the potential pathway for the steal physiologic mechanism, and maintains continuous dialysis access in these difficult patients.

Aged↗

PubMed1997

Endothelium on the flow surface of human aortic Dacron vascular grafts.

PURPOSE: We have previously observed endothelium on two human vascular prostheses explanted under optimal conditions for flow surface preservation. In this study we sought to further verify the hypothesis that endothelialization can occur on clinical grafts and that it can be detected in specimens that have been promptly removed and properly preserved in a timely manner. METHODS: We studied 29 aortic grafts. Of these, 11 Dacron bypass grafts were in a condition suitable for analysis with light microscopy and immunocytochemistry staining, and scanning and transmission electron microscopy. RESULTS: Three grafts had endothelium beyond the pannus, identified by factor VIII/ vWF, Ulex europaeus agglutinin, and collagen IV positivity. Specimen A, a knitted 6-year implant, was preserved by embalming 3 hours after the patient's death and had a firmly attached outer capsule with fibroblasts, collagen, giant cells, and microvessels in the interstices. Specimen B, a woven 18-year implant, was retrieved at reoperation and immediately fixed in 10% formalin; it had no outer capsule and no tissue ingrowth. Specimen C, a woven 7-year implant, was removed and fixed 5 hours after the patient's death; it had a firmly attached outer capsule but no tissue ingrowth beyond the outer portion of the wall. CONCLUSIONS: The rapidity with which the specimens were fixed probably enabled identification of endothelium. These findings suggest that endothelialization of synthetic arterial grafts may occur more frequently in human beings than previously recognized.

Aged↗

PubMed1997

Immunocytochemical determination of cell type and proliferation rate in human vein graft stenoses.

PURPOSE: Vascular reconstructions are prone to fail as a result of the development of stenotic lesions, which have historically been attributed to myointimal hyperplasia. In animal models, these lesions are associated with marked proliferative smooth muscle cell (SMC) response to vascular injury. However, recent studies using sensitive immunocytochemical techniques in human lesions have generally failed to detect significant cellular proliferation. To clarify the role of cellular proliferation in humans, we characterized the cellular composition and proliferative index of 14 early infrainguinal vein graft stenoses. METHODS: All infrainguinal vein grafts at our institution are prospectively enrolled in a duplex surveillance protocol, the details of which have been previously reported. Among 98 grafts placed within the last year, 11 patients were identified with 14 progressive, focal, high-grade lesions that met previously established threshold criteria for prophylactic revision to prevent graft thrombosis. Lesions were first detected from 1 week to 7 months after surgery and were removed and replaced with segmental interposition grafts (1.5 to 10 months). Freshly excised lesions were placed in Methyl Carnoy's fixative, paraffin embedded, and serially sectioned. The cellular composition of each lesion was determined with cell-specific immunochemical reagents: alpha SMC actin, von Willebrand factor (endothelial cell), CD 68 (macrophage), and CD 45RB (monocyte). Actively proliferating cells were identified using antibody to proliferating cell nuclear antigen (PCNA). The identity of PCNA-positive cells was determined by double-label immunocytochemical staining, and the proliferative index (PCNA-positive cells/total cells x 100) was calculated by computer-assisted counts of representative gridded cross-sections of each lesion. RESULTS: All excised lesions demonstrated marked thickening with severe luminal encroachment and were highly cellular, with a predominance of alpha SMC actin+. Endothelial cells on the blood flow surface were present to a variable degree, and seven lesions exhibited striking numbers of macrophages and monocytes. The latter cell types were most abundant near microvessels in the deep neointima and adventitia. Active cellular proliferation was identified primarily in SMCs, with a mean PCNA index of 1.34%. However, significant PCNA reactivity was not limited to SMCs, but was also identified in macrophages and monocytes, particularly in lesions greater than 3 months old. CONCLUSIONS: Previous immunocytochemical studies of human coronary restenosis atherectomy specimens have generally detected low rates of cellular proliferation (0.5%), but these lesions may not truly represent myointimal hyperplasia, rather a mixture of atherosclerosis, thrombosis, and "restenosis." In contrast, the present study of early human vein graft lesions detected by duplex surveillance indicates that significant cellular proliferation occurs, although rates are lower than those obtained in animals such as the rat carotid injury model. In addition, although SMCs are the predominant proliferating cell type in human vein grafts, our identification of proliferating monocytes and macrophages raises the question of the contribution of an inflammatory component to the development of human lesions. The present study represents the first report of PCNA determination in a series of human infrainguinal vein grafting procedures.

Cell Division↗

PubMed1996

Vitamin E levels in human atherosclerotic plaque: the influence of risk factors.

Recent studies suggest that vitamin E may be an important preventative factor in the development and progression of atherosclerosis. In order to more clearly define the role of vitamin E in atherosclerosis, we measured vitamin E, conjugated diens, and lipid flurochromes, as well as cholesterol, triglycerides and phospholipid in arterial and venous tissue of 83 patients. Serum cholesterol and triglyceride levels were significantly higher (P < 0.05) in patients with aortic occlusive (AIOD) and aneurysmal (AAA) disease than in control organ donors (OD). Tissue cholesterol concentrations were significantly elevated in AAA tissue when compared to OD and tissue from patients with peripheral occlusive disease (POD). Tissue from patients with AIOD contained greater concentrations of phospholipid (PL) than were measured in patients with POD and in OD. Vitamin E concentrations were highest in POD tissue and approximately 3.0, 2.0, and 1.6 fold greater than OD, AIOD and AAA tissue respectively. Diene conjugates and lipid flurochromes, measures of early and intermediate products of lipid peroxidation, were markedly elevated in all diseased arterial tissue compared to controls. There were no significant differences in tissue or serum lipid levels between saphenous vein (SVBG) and diseased vein grafts (DVG). However, conjugated diene concentrations were elevated in DVG compared to SVBG. Vitamin E levels were significantly elevated in diseased arterial and venous tissue (AIOD, AAA, POD, DVG) removed from patients with diabetes (P = 0.013) and hypertension (P = 0.049) compared to those without these risk factors. Diabetes was the only risk factor associated with significantly increased (P = 0.005) levels of vitamin E when only data from atherosclerotic arterial tissue (AAA, POD, AIOD) were analyzed. These preliminary data provide additional evidence of altered vitamin E metabolism and free radical processes in the tissues of patients with various manifestations of atherosclerosis.

Adolescent↗

PubMed1996

Clinical presentation and management of iatrogenic colon perforations.

BACKGROUND: Because iatrogenic colonic perforation is uncommon, surgical management of this complication has been based on the civilian trauma experience. In this study, we determine the incidence, clinical presentation, and management of colonic perforations resulting from colonoscopy or barium enema. PATIENTS AND METHODS: The medical records of all patients with colorectal perforations due to barium enema or colonoscopy seen over a 5-year period were reviewed. RESULTS: Twenty-one patients, 12 males and 9 females aged 66 +/- 16 years, undergoing evaluation for polyps and bleeding (11), diverticulosis (4), diarrhea (2), or miscellaneous indications (4) sustained colonic perforation from colonoscopy (18; 0.20%) or barium enema (3; 0.10%). Abdominal pain, 66% (13), and fever, 24% (5), were the most frequent symptoms encountered and extraluminal air, 67% (14), the most common radiologic finding. The site of perforation was the rectosigmoid in 62% (13) of patients. Eighteen patients underwent surgery; 11 within 24 hours (group I) and 7 patients within 6.0 +/- 4 days (group II). Fifty percent (9 of 18) had primary repair or resection with anastomosis without mortality. Of the 6 patients initially treated nonoperatively, 3 subsequently underwent surgery. Both deaths, one in group I and one in group II, occurred in patients who had colonic diversion for perforation following colonoscopy. CONCLUSION: We conclude that in the absence of significant contamination either primary repair or resection and anastomosis can be performed with acceptable morbidity for iatrogenic perforations of the colon.

Adolescent↗

PubMed1996

Comparative analysis of percutaneous transluminal angioplasty and operation for renal revascularization.

Contemporary patients requiring renal revascularization often have diffuse atherosclerosis, and increasingly undergo intervention for salvage of renal function rather than control of hypertension alone. Risk-benefit analyses and outcome data are difficult to obtain, since few reports have analyzed a modern, unselected series of consecutive patients subjected to renal revascularization by surgical as well as interventional techniques. We reviewed our 5-year experience with 76 consecutive renal revascularizations in 63 patients. Indications for intervention were hypertension and renal salvage, 60 percent (n = 38); hypertension, 24 percent (n = 15); renal salvage, 9.5 percent (n = 6); and other, 6.5 percent (n = 4). Ninety-four percent (n = 59) of patients had atherosclerotic occlusive disease of the renal arteries. Percutaneous transluminal angioplasty (PTA) was initially performed on 18 renal arteries in 16 patients, of whom 56 percent (n = 9) subsequently required surgical reconstruction. Fifty-eight surgical reconstructions were performed in 56 patients and consisted of aortorenal bypass (n = 27), aortorenal endarterectomy (n = 18), and extra-anatomic bypass (n = 13). Concomitant aortic replacement was required in 57 percent (n = 32) of patients. Preoperative risk factors and operative indications did not differ between the PTA and surgical reconstruction groups. Morbidity and mortality rates associated with PTA were 33 percent and 4.8 percent, respectively, while for surgical treatment the morbidity rate was 7 percent and the mortality rate 5.3 percent (P = NS). Functional improvement was achieved in 74 percent of surgically treated patients compared with 22 percent of PTA-treated patients (P < 0.01). Actuarial renal artery primary patency at 48 months was 81 percent for the surgery group and 17 percent for the PTA group (P < 0.01). Aortorenal bypass, endarterectomy, and extra-anatomic bypass were equally efficacious (P > 0.05). The results of surgical reconstruction are excellent, offering more durable patency and functional improvement than PTA, without increased risk. The operation should be tailored to fit the individual patient's disease, since the results of endarterectomy and bypass procedures are equivalent.

Aged↗

PubMed1996

Incidence and histologic characteristics of blebs in patients with abdominal aortic aneurysms.

PURPOSE: Aortic blebs-focal outpouchings within aortic aneurysms-may contribute to their eventual rupture. In this study we determine the incidence of aortic blebs and describe their microscopic features. METHODS: Computed tomographic scans of the abdominal aorta were obtained in 188 patients with aortic diameters measuring > or = 3 cm and were independently evaluated by a radiologist. The number and location of blebs were recorded, and each was measured with calipers. Sixteen blebs, with an adjacent uninvolved aneurysmal segment of aorta, and tissue from two patients with ruptured aneurysms were examined by light microscopy and immunohistochemical analysis. Specimens from six blebs and five aneurysms were examined for alpha 1 (I) procollagen messenger RNA by in situ hybridization. RESULTS: Twenty blebs, ranging in size from 5 to 30 mm (mean, 12 +/- 7 mm), were detected in 11% (20 of 188) of computed tomographic scans. Blebs were observed in 10% (11 of 111) of patients with aortic diameters between 3.0 and 4.9 cm, 10% (6 of 61) of patients with aneurysms between 5.0 and 6.9 cm, and 19% (3 of 16) of patients with aortic diameters > or = 7 cm. Histologically, the major difference between the aneurysmal aortic wall and blebs was found in the media. In aneurysmal aortas, the media consisted of multiple layers of fragmented elastic lamellae, whereas the number of elastic tissue elements along the circumference of the blebs progressively decreased; only a few isolated fragments of elastic tissue were present at the apices. Histologic evidence of rupture was evident in two specimens. A chronic inflammatory cell infiltrate composed of T and B lymphocytes, plasma cells, and macrophages, common to both the aneurysmal and the blebs, was most prominent in the adventitia of aneurysmal tissue, but involved both the media and adventitia of the blebs. In situ hybridization demonstrated the presence of alpha 1 (I) procollagen messenger RNA in four of the five aneurysm segments that were evaluated, compared with only one of six blebs. CONCLUSIONS: Blebs were discovered in aneurysms of all sizes; their frequency appeared to be unrelated to aneurysm size. The presence of inflammatory cell infiltrates and absence of alpha 1 (I) procollagen messenger RNA in five of six blebs suggest that a local imbalance of matrix degradation and repair plays a role in the cause of these lesions. Attenuation of the aortic wall accompanying the formation of blebs may predispose these sites to rupture.

Aorta, Abdominal↗

PubMed1996

The relative contributions of carotid duplex scanning, magnetic resonance angiography, and cerebral arteriography to clinical decisionmaking: a prospective study in patients with carotid occlusive disease.

PURPOSE: Recent reports suggest that 80% to 90% of patients can safely undergo carotid endarterectomy on the basis of duplex scanning alone without cerebral angiography. Other investigators have recommended that a complementary imaging study such as magnetic resonance angiography (MRA) also be obtained. METHODS: We prospectively evaluated 103 consecutive patients with carotid occlusive disease. Eighty percent of patients were symptomatic. All 103 patients underwent duplex scanning and arteriography. Additional noninvasive tests included computed tomography, magnetic resonance imaging, and MRA in 50%, 56%, and 48% of patients, respectively. At a multispecialty conference all studies except angiograms were reviewed, and a treatment decision was made by a panel of attending vascular surgeons, neurosurgeons, and neurologists. The cerebral angiograms then were reviewed and changes made to final treatment plans were noted. RESULTS: After review of noninvasive studies, 30 of 103 of patients (29%) were believed to require arteriography because of diagnostic uncertainty of carotid occlusion in three patients, suggestion of nonatherosclerotic disease in four, suggestion of proximal disease in two, suboptimal noninvasive studies in one, and uncertainty of therapy despite good-quality noninvasive studies in 20 patients primarily with borderline stenoses and unclear symptoms. In 10 of these 30 patients (33%) management decisions were changed on the basis of angiogram results. Of the remaining 73 patients (71%) in whom the panel felt comfortable proceeding with operative or medical therapy without angiography, only one patient (1.4%) would have had management altered by results of angiography. MRA results concurred with duplex findings in 92% of studies, but did not alter management in any patient. CONCLUSIONS: In patients with good-quality duplex images, focal atherosclerotic bifurcation disease, and clear clinical presentation, treatment decisions can be made without arteriography. In 30% of patients angiography is useful in clarifying decisionmaking. MRA is unlikely to influence management decisions and is thus rarely indicated.

Aged↗

PubMed1995

Cellular origin and rate of endothelial cell coverage of PTFE grafts.

To determine the origin, cell type present, and rate of endothelial cell coverage of PTFE grafts, 5-cm segments of 4-mm-diameter, 60-microns PTFE grafts were implanted end-to-end bilaterally in the carotid arteries of greyhound dogs. An external jugular vein wrap was applied to the outer surface of one of the PTFE grafts; the contralateral PTFE graft, which was unwrapped, served as its control. Two dogs each were sacrificed at 3, 5, 7, 14, 21, 28, and 35 days postimplantation. Anastomotic endothelial ingrowth was analyzed using scanning electron microscopy. Microvessel ingrowth was documented in longitudinal H&E sections. Cell identity was established by immunohistochemistry with factor VIII antibody, Ulex europaes, leukocyte common antigen, and antibodies to alpha-actin, desmin, vimentin, and basic fibroblast growth factor. All grafts were patent at the time of harvest. Endothelial cell migration from the native artery adjacent to the anastomosis commenced at 7 days, extended to 5 mm beyond the proximal and distal anastomoses by 14 days and to 1.0 cm by 35 days. Endothelialization of the mid-portion of the wrapped grafts occurred via microvessel ingrowth, a process which began at 7 days. Microvessels reached the luminal surface by 28 days and an endothelial cell monolayer was established by 35 days. Wrapping the external surface of the graft with vein increased the rate of graft healing. Basic fibroblast growth factor was detectable by immunohistochemistry at the vein wrap-graft interface in the first 14 days.

Animals↗

PubMed1995

Clinical and CT evaluation of a new stretch polytetrafluoroethylene aortic graft.

A new stretch polytetrafluoroethylene (PTFE) aortic graft became available for clinical use in early 1991. We prospectively evaluated our first 107 stretch aortic PTFE grafts by means of serial CT imaging and compared them with a cohort of concurrently placed Dacron grafts. Stretch PTFE requires no preclotting and is claimed to resist long-term dilation and conform well to anastomoses. Consecutive patients undergoing placement of stretch PTFE grafts were seen at least yearly. Within the first 2 years after implantation, contrast-enhanced CT scans of the abdomen and pelvis were obtained. Caliper measurements were made of the native arteries and the body and any limbs of the aortic grafts. Graft elongation was assessed by noting distortions from the normally circular or minimally ovoid configuration of the grafts on transverse CT images. Indications for grafting were elective repair of abdominal aortic aneurysm in 60 patients, aortoiliac occlusive disease in 31, both aneurysm and occlusive disease in eight, and ruptured abdominal aortic aneurysm in eight. The overall operative mortality rate was 6.5%. There were two early postoperative graft limb thromboses resulting from hypercoagulable states, and there was one graft infection. Mean follow-up was 14.1 months (range 1 to 34 months). CT scans were obtained from 61 patients with stretch PTFE grafts and 10 with concomitantly placed Dacron grafts. Ten patients had two or more postoperative CT scans. Primary stretch PTFE patency was 98% and secondary patency, 100%. There was significantly less dilation of both the graft body and limbs in the stretch PTFE group (body mean 16.5%, range 6.3% to 28.1%; limb mean 19.3%, range 10% to 43%) compared to the Dacron group (body mean 33%, range 22% to 78%; limb mean 62%, range 12.5% to 88.9%) (p < 0.01, unpaired t test).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

Aspiration pneumonia following surgically placed feeding tubes.

BACKGROUND: The enteral route is preferred in surgical patients requiring nutritional support; however, controversy surrounds the choice of location of feeding tube placement. Although jejunostomy has been commonly accepted as superior to gastrostomy for long-term nutritional support because of an assumed lower risk of aspiration pneumonia, recent studies suggest that reevaluation of common practices of surgical tube placement is warranted. PATIENTS AND METHODS: We conducted a retrospective chart review of gastrostomy and jejunostomy procedures from 1986 to 1993. Demographic information and complications related to the procedure were reviewed. Aspiration pneumonia was defined as respiratory symptoms, leukocytosis, and infiltrate on chest radiograph. RESULTS: Sixty-nine gastrostomies and 86 jejunostomies were performed during the study period. Six patients were diagnosed with aspiration pneumonia; 2 cases of which occurred with jejunostomy and 4 cases occurred with gastrostomy (P = not significant). CONCLUSIONS: There was no difference in rates of pulmonary aspiration or other complications between gastrostomy and jejunostomy. We suggest that when a surgically placed feeding tube is required, the determination of appropriate procedure be based on clinical factors such as the technical difficulty of the operation or long-term feeding goals.

Enteral Nutrition↗

PubMed1995

Abdominal wall hernias in patients with abdominal aortic aneurysmal versus aortoiliac occlusive disease.

BACKGROUND: This study was undertaken to determine the incidence of ventral incisional hernias (VIHs) and inguinal hernias (IHs) in patients with abdominal aortic aneurysmal (AAA) versus those with aortoiliac occlusive disease (AIOD). PATIENTS AND METHODS: The medical records of 193 patients (128 with AAA and 65 with AIOD) who had undergone elective aortic reconstruction were reviewed to determine the number and location of abdominal wall hernias (AWHs). RESULTS: Forty-one AWHs (28 IHs and 13 VIHs) were detected in patients with AAA compared to 13 (11 IHs and 2 VIHs) in patients with AIOD. There was a significantly greater incidence of VIHs in patients with AAA versus patients with AIOD (10% versus 3%, P < 0.05) and recurrent AWHs (28% versus 19%, P < 0.01), but not of IHs (22% versus 17%). CONCLUSION: Patients with AAA have a higher incidence of VIHs and recurrent AWHs--without a corresponding increase in patient-related risk factors--than patients without aneurysm, suggesting that as yet unidentified etiologic factors may contribute to the development of AWHs in these patients.

Aorta, Abdominal↗

PubMed1995

Application of computed tomography for surveillance of aortic grafts.

BACKGROUND: This study was undertaken to assess the application of computed tomography (CT) for surveillance of aortic grafts. METHODS: Demographics, operative technique, and graft type and size at the time of implantation of aortic grafts in 178 patients were recorded. CT measurements of graft diameters were made with calipers. Data were analyzed by analysis of variance, multiple regression, and chi-squared methods. RESULTS: One hundred twenty-eight (72%) bifurcated grafts and 50 (28%) tube grafts were placed for aneurysmal disease (49%), aortoiliac occlusive disease (47%), ruptured aneurysm (2.3%), anastomotic aneurysm (1%), and graft aneurysm (0.6%). Mean implant time was 43.3 +/- 3.2 months. A total of 143 Dacron prostheses (74 woven, 69 knitted) and 35 polytetrafluoroethylene prostheses were placed. Mean percentage dilation was 49.2 +/- 4.0 for knitted prostheses, 28.5 +/- 3.0 for woven prostheses, and 20.6 +/- 1.9 for polytetrafluoroethylene prostheses compared with the graft implant size. A significant correlation was seen between graft dilation (more than 50%) and graft construction with knitted prostheses (p < 0.01, Tukey's range test). Complications detected by CT occurred in 24 (13.5%) patients including supragraft aneurysms (seven), distal anastomotic aneurysms (five), proximal anastomotic aneurysms (three), graft infections (two), perigraft fluid collections (two), graft aneurysm with thrombus and distal embolization (two), and nonvascular complications (three). CONCLUSIONS: CT is a useful modality for postoperative imaging of aortic prostheses. Routine surveillance may detect complications before they become clinically apparent.

Aged↗

PubMed1995

Prospective evaluation of peripheral vascular disease in heart transplant recipients.

PURPOSE: Retrospective reviews suggest that the progression of peripheral vascular disease (PVD) may be accelerated in heart transplant recipients. This study was undertaken to determine the incidence and to identify those risk factors that may be associated with the development or progression of PVD in these patients. METHODS: Between January 1990 and December 1993 a prospective vascular screening protocol including abdominal ultrasonography, Doppler-derived ankel-brachial pressure indexes (ABI), and carotid artery duplex imaging was added to the routine preoperative and annual postoperative evaluation of 239 heart transplant recipients. RESULTS: Thirty-one significant vascular lesions were detected in 10% (24 of 239) of patients 52 +/- 9 years of age at a mean of 3.2 years after transplant. The distribution of lesions included carotid artery stenosis (11), femoropopliteal occlusive disease (10), aortoiliac occlusive disease (five), aortic aneurysm (four), and renal artery stenosis in one patient. Revascularization procedures were performed in 12 (50%) patients (carotid endarterectomy (four), aortobifemoral bypass grafting (three), abdominal aortic aneurysm repair (two), transluminal angioplasty (two), splenorenal bypass (one), and femorotibial bypass grafting (one)). One patient with diabetes mellitus (DM) was found to have noncompressible vessels during pretransplant evaluation. An additional 26 patients (11%), seven with DM, had noncompressible vessels in the lower extremities during the follow-up period. Logistic regression analysis revealed that the development of posttransplant PVD was associated with smoking (p < 0.05) and ischemic cardiomyopathy as an indication for transplantation (p < 0.05). The development of noncompressible vessels was associated with younger age (p < 0.05) and the presence of diabetes (p < 0.05). CONCLUSION: Posttransplant peripheral vascular disease occurred in 10% of heart transplant recipients and is associated with pretransplant ischemic cardiomyopathy and smoking. A previously unrecognized subgroup of patients who have noncompressible vessels after operation is described. If the long-term survival of the heart transplant recipient is to be improved, routine follow-up to identify and treat those patients at greater risk appears justified.

Adolescent↗

PubMed1995

Distinguishing carotid artery pseudo-occlusion with color-flow Doppler.

BACKGROUND AND PURPOSE: This study was undertaken to determine the impact of color-flow Doppler on the accuracy of noninvasive carotid imaging for distinguishing an internal carotid artery pseudo-occlusion (string sign) from a complete occlusion. METHODS: From January 1985 to January 1994, review of noninvasive vascular studies, arteriograms, and operative reports of 26 consecutive patients undergoing 27 carotid endarterectomies for carotid pseudo-occlusion was performed. Further review was conducted of all patients identified with carotid occlusion by noninvasive testing who underwent confirmatory arteriography during the same interval. RESULTS: Conventional gray-scale duplex scanning (January 1985 to December 1989) correctly identified 3 of 11 (27%) pseudo-occluded internal carotid arteries compared with 15 of 16 (94%) internal carotid artery pseudo-occlusions correctly identified by color-flow Doppler (January 1990 to June 1994) (P < .01). Similarly, carotid occlusion was more accurately identified by color-flow Doppler (33 of 33, 100%) compared with gray-scale duplex scanning (19 of 27, 90%) (P < .01). CONCLUSIONS: The addition of color-flow Doppler to the duplex evaluation of the extracranial carotid circulation improves the accuracy of distinguishing carotid pseudo-occlusion from the occluded internal carotid artery and may obviate the need for arteriography to identify patients with this critical level of carotid stenosis.

Acute Disease↗

PubMed1995

Surgical treatment of symptomatic biliary stones in patients with cystic fibrosis.

Patients with cystic fibrosis have a high incidence of cholelithiasis. However, few studies have addressed the operative therapy for cholelithiasis in this group of patients with poor pulmonary function. We reviewed six patients with cystic fibrosis who were treated for symptomatic biliary stones. Five patients underwent cholecystectomy for chronic cholecystitis. One patient with extremely poor pulmonary status presented with choledocholithiasis and cholangitis, which was successfully treated with endoscopic sphincterotomy followed by ursodeoxycholic acid therapy. Five of these six patients had significant relief of their symptoms. One patient never recovered completely from the operation and eventually died from continued pulmonary deterioration. We conclude that in patients with cystic fibrosis and symptomatic biliary stones, careful attention to pulmonary care can afford safe, elective cholecystectomy. More conservative treatment is indicated in patients with marginal pulmonary reserve.

Adolescent↗

PubMed1994

Factors influencing the safety of colostomy closure in the elderly.

Although colostomy closure is a commonly performed surgical procedure, there remains concern that the attendant risks may be misjudged, especially in the elderly. The purpose of this study was to evaluate the safety of performing colostomy closure and to define the factors that may influence morbidity and mortality in patients over the age of 70. Three hundred seven patients (178 males, 129 females) underwent colostomy closure over a 5-year period. The mean age was 52 years and 84 (27%) of the patients were 70 years or older. The indications for colostomy included diverticulitis, 115 (38%); malignancy, 47 (15%); perforation 35 (11%); trauma, 34 (11%); congenital anomalies, 26 (8%); obstruction, 13 (4%); bleeding, 6 (2%); colovesical fistulae, 6 (2%); polyps, 2 (0.7%); and miscellaneous, 23 (8%). An end colostomy was performed in 193 (63%) patients and a transverse loop colostomy in the remaining 114 (37%). There were no deaths. Complications occurred in 27 (9%) patients: 17 were directly related to colostomy closure (8 wound infections, 3 intraabdominal abscesses, 3 small bowel obstructions, 2 anastomotic strictures, and 1 anastomotic leak) while 10 were nonsurgical. Risk factors statistically associated with increased morbidity included age > 70 years (13% versus 5%), end versus loop colostomy (10% versus 2%), an operative time > 2 hr, and estimated blood loss > or = 500 ml (P < 0.05). ASA classification was only predicative of postoperative complications in patients over 70 years of age. We conclude that although colostomy closure can be performed without mortality, the increased morbidity associated with this procedure in patients 70 years or older necessitates careful preoperative assessment.

Adolescent↗