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Biomedical subjects

E L Chaikof

Publications and source records attributed to E L Chaikof.

At least 55 records · Page 3Linked to original sources
PubMed1995

Peripheral vascular complications of aortic dissection.

BACKGROUND: The incidence and management of peripheral vascular complications of aortic dissection is unsettled. PATIENTS AND METHODS: Peripheral vascular complications of spontaneous aortic dissection were examined in a 5-year retrospective review. Patients who had peripheral vascular complications were categorized as group A; those without as group B. RESULTS: Thirty-eight major vessels were affected in 18 patients. No patient underwent a peripheral vascular procedure for complications of the carotid, subclavian, celiac, mesenteric, or renal arteries. Three patients underwent femorofemoral bypass for acute iliofemoral occlusion due to dissection. A fourth patient had repair of an iliac aneurysm that developed as a complication of chronic dissection. The mortality rate was 17% for group A, 9% for group B, and 10% overall. Following repair of the aortic dissection, the majority of the peripheral vascular complications resolved. CONCLUSIONS: Peripheral revascularization is infrequently required in aortic dissection following primary dissection repair.

Adult↗
PubMed1995

Carotid artery shortening: a safe adjunct to carotid endarterectomy.

PURPOSE: Kinks and coils of the extracranial carotid artery system have been described in conjunction with atherosclerotic disease of the internal carotid artery. The purpose of this study was to determine whether adding a carotid artery shortening procedure to carotid endarterectomy affected perioperative mortality and stroke-morbidity rates or late restenosis. METHODS: A retrospective chart review of all patients who concurrently underwent carotid endarterectomy and ipsilateral carotid artery shortening between 1983 and 1992 was performed. Long-term follow-up was obtained by contacting the primary physician or patient, and carotid artery duplex scans were obtained. RESULTS: One hundred seven patients were found to have undergone concurrent carotid endarterectomy and carotid artery shortening. The age range was 47 to 89 years, with 53 female and 54 male patients. Indications for surgery in this group were transient ischemic attacks in 28%, stroke in 18%, amaurosis fugax in 7%, and high-grade asymptomatic stenosis in 47%. Shortening procedures were performed by use of a variety of techniques at the completion of endarterectomy. The combined 30-day mortality and stroke morbidity rate was 2.7%, with two postoperative deaths and one stroke. In this same period, a total of 1072 carotid endarterectomies were performed, and the combined 30-day mortality and stroke morbidity rate was 4.0%. During late follow-up there were no ipsilateral strokes, recurrent symptoms, or significant restenoses. CONCLUSIONS: This experience suggests that the addition of a shortening procedure to carotid endarterectomy can be performed without increased morbidity and mortality rates and, when deemed appropriate, is a procedure with which the vascular surgeon should be familiar.

Aged↗
PubMed1995

Treatment of recurrent cerebrovascular disease. Review of a 10-year experience.

OBJECTIVE: The authors determined whether carotid endarterectomy in patients with recurrent cerebrovascular disease poses a greater perioperative risk than for those individuals undergoing first-time carotid endarterectomy. SUMMARY BACKGROUND DATA: A percentage of patients undergoing carotid endarterectomy for atherosclerosis experience recurrent cerebrovascular disease. Reoperation may be difficult because of postoperative scarring of the soft tissues of the neck and the carotid artery itself. Such patients were believed to be at greater risk for perioperative morbidity than those undergoing first-time carotid endarterectomy. METHODS: To address this concern, the authors retrospectively reviewed their experience with 69 patients who underwent repeat carotid endarterectomies over a recent 10-year period of time. This subgroup represented 6.4% of 1072 total carotid endarterectomies performed during the same time period. The average extent of stenosis on the operated side was 81% and the time elapsed after previous endarterectomy averaged 83 months. Twelve patients (17.4%) had contralateral internal carotid occlusion, and 30 patients (43.5%) had undergone previous endarterectomies on the contralateral side. RESULTS: Complications within 30 days of operation included two deaths (2.9%) and one stroke (1.4%), for a combined stroke and death rate of 4.3%. Six patients developed cervical hematomas requiring drainage; one of these had rupture of a saphenous vein patch. No patient had a significant cranial nerve injury in the reoperative group, whereas 2.0% of patients undergoing first-time carotid endarterectomy had cranial nerve injuries. Overall, these results compared favorably with a combined stroke and death rate of 4.0% among 1003 patients who underwent first-time carotid endarterectomy during the same period. CONCLUSIONS: This review suggests that repeat carotid endarterectomy can be performed safely in individuals with severe recurrent carotid stenosis, with morbidity and mortality rates similar to those for patients undergoing first-time carotid endarterectomies. For this population, reoperative carotid endarterectomy represents a safe and important mechanism for the prevention of stroke.

Aged↗
PubMed1994

Carotid endarterectomy in the octogenarian.

During a 10-year period from January 1983 to December 1992, 79 carotid endarterectomies were performed in patients aged 80 years or older. This represented 7.4% of the total patient population undergoing carotid endarterectomy at Emory University Hospital. The indications for surgery in this elderly population were transient ischemic attacks in 24 (30.3%), cerebrovascular accident in 12 (15.2%), amaurosis fugax in seven (8.9%), vascular tinnitus in one (1.3%), and asymptomatic stenosis in 35 (44.3%). The average degree of ipsilateral stenosis was 76.8%. Concomitant risk factors included coronary artery disease in 43%, systemic arterial hypertension in 51.9%, diabetes mellitus in 10.1%, and significant smoking history in 53.2%. Seventy-six percent of the procedures were performed under local anesthesia, and in all but two intraluminal shunts were used. Combined 30-day mortality and postoperative stroke morbidity in this population was 1.3% (one patient). Long-term follow-up ranging from 1 to 10 years (average 35 months) revealed no ipsilateral strokes. This experience suggests that carotid endarterectomy can be performed in an elderly population with morbidity and mortality rates similar to those in a younger cohort.

Aged↗
PubMed1994

Paradoxical embolism and acute arterial occlusion: rare or unsuspected?

PURPOSE: The high prevalence of clinically silent venous thrombosis and the presence of a patent foramen ovale (PFO) in up to 35% of the general population suggests that paradoxical emboli may be the cause of an ischemic stroke or a peripheral thromboembolic occlusion more often than is presently considered. This study was undertaken to review our experience with presumed paradoxical embolism. METHODS: Hospital records were reviewed for all patients diagnosed with both a documented PFO and a thromboembolic event between January 1970 and June 1993. Patients with a ventricular or an atrial septal defect or a probable pulmonary arteriovenous fistula were excluded. RESULTS: The presumptive diagnosis of paradoxical embolism was made in seven patients. There were five men and two women, with a median age of 43 years. Four patients were admitted with an acute cerebral ischemic event, and in three others hospitalization was prompted by the development of an acutely ischemic limb (two upper extremity; one lower extremity). In none was there evidence of angiographically significant peripheral or extracranial atherosclerotic occlusive disease. Symptoms suggestive of pulmonary emboli were noted in two patients, and in only one patient was there evidence on physical examination of a deep venous thrombosis. Before 1988 the diagnosis of paradoxical embolism had been made in only one patient after postmortem examination. All six patients who were discharged were available for follow-up (mean 20 months; range 6 to 60 months). There was one late death from lung cancer. Recurrent paradoxical emboli have not been documented during the follow-up period. CONCLUSIONS: The incidence of presumed paradoxical embolism has increased dramatically in the recent past as a consequence of our improved ability to unequivocally detect PFO with associated physiologic shunting. The suspicion of this heretofore "rare" event should be raised, particularly in the young or middle-aged adult diagnosed with an acute thromboembolic event. Until the risk of recurrent ischemic events in the presence of a PFO is better defined, we currently recommend closure of the foramen ovale after a significant or recurrent paradoxical embolus. Otherwise, the selective use of intracaval filters, antiplatelet therapy, and oral anticoagulation remain undefined.

Acute Disease↗
PubMed1994

Ischemic nephropathy and concomitant aortic disease: a ten-year experience.

PURPOSE: The durability of renal preservation after surgical intervention has not been well defined, particularly in patients with associated aortic disease. A review of all patients at the Emory University Hospital with renal insufficiency (creatinine level > or = 1.8) and concomitant atherosclerotic aortic and renovascular disease was undertaken. METHODS: Fifty patients underwent both renal revascularization (71 kidneys) and the repair of aneurysmal or symptomatic aortic occlusive disease between 1982 and 1992. Hypertension was present in 96% of patients and diabetes was present in 10%. The preoperative estimated glomerular filtration rate (EGFR) was 25.18 +/- 8.29 ml/min (creatinine level 3.1 +/- 1.5 mg/dl). Operative management included bilateral renal artery repair (n = 21), unilateral repair alone (n = 17), and unilateral repair with contralateral nephrectomy (n = 12). The relative percent change in the postoperative EGFR (> or = 7 days after operation) increased by at least 20% in 42% of the patients, had decreased by 20% or more in only 4%, and was otherwise categorized as unchanged in the remaining 54% of the study group. RESULTS: The 30-day operative mortality rate was 2.0% (1 of 50). Forty-five of the surviving 49 patients (91.8%) were available for follow-up (median 49 months). During this period nine patients (18.4%) eventually required dialysis, four within 6 months of operation, and 19 patients died. Neither subgroup experienced a retrieval of renal function after operation. Five-year survival rate was 61%, and a trend was noted between the risk of death and the relative change in EGFR after operation (p = 0.13). The likelihood of eventually requiring long-term dialysis was highest among those patients with low preoperative functional renal reserve as measured by preoperative creatinine level of 3 mg/dl or greater (p < 0.0001), or preoperative EGFR less than 20 ml/min (p = 0.0001). Blood pressure was cured or improved in 50% at late follow-up. CONCLUSIONS: Early improvement of renal function may be observed in nearly one half of patients subjected to combined aortic and renal revascularization. Nonetheless, renal preservation may not be sustainable in patients with compromised preoperative function. Intervention before marked functional decline remains the best option for minimizing the risk of eventual dialysis.

Aged↗
PubMed1993

Spinal cord ischemia after abdominal aortic procedures: is previous colectomy a risk factor?

Pelvic ischemia is a potential cause of spinal cord infarction after abdominal aortic surgery. Although postoperative cord ischemia is often unpredictable, certain patient subgroups may be at greater risk and identified as such before surgery. The case of a 64-year-old man who became paraplegic after an infrarenal aortoiliac aneurysm repair is reported. He had lost his mesenteric arcade as a result of a prior colectomy. Aortoiliac reconstruction required the interruption of antegrade hypogastric blood flow. Restoring circulation to at least one hypogastric artery is a tenet of modern aortic surgery. However, the loss of both internal iliac arteries and the occlusion of the inferior mesenteric artery at its origin are occasionally well tolerated because of a mesenteric collateral pathway. Colectomy eliminates the mesenteric arcade and further increases the risk of spinal ischemia when attempts at pelvic revascularization have failed.

Aorta, Abdominal↗
PubMed1992

PEO enhancement of platelet deposition, fibrinogen deposition, and complement C3 activation.

Whereas it has been commonly thought that adding polyethylene oxide PEO to a surface would diminish the capacity of the surface to cause deposition of platelets and of fibrinogen, and to activate complement C3, we present data showing exactly the opposite. These unexpected results are obtained with low molecular weight (2000) PEO, and are not found with higher molecular weight (20,000) PEO.

Animals↗
PubMed1992

Acute arterial thrombosis in the very young.

The case records of all infants under the age of 6 months who underwent surgery for acute arterial thrombosis between January 1980 and September 1991 were reviewed. Seven infants (nine ischemic limbs) were identified and ranged in age from 5 days to 5 1/2 months (mean 2.4 months); all weighed less than 5 kg (mean 3.9 kg). The cause in each case was iatrogenic. Diagnosis was based on the presence of a cool, mottled extremity associated with the absence of insonated peripheral arterial Doppler signals. Treatment included aortoiliac thrombectomy (n = 2), femoral artery thrombectomy with primary closure (n = 4), femoral artery thrombectomy with autogenous saphenous vein patch (n = 1), and axillary artery thrombectomy with end-to-end anastomosis (n = 1). Palpable pulses were restored in five (56%) of nine limbs and Doppler signals in the remaining limbs. There were no instances of limb loss. Excluding aortoiliac thrombectomy, palpable peripheral pulses were reestablished in only 40% of extremities. Thrombectomy is a safe and simple procedure in even the very youngest of patients with arterial insufficiency, but surgical optimism should be tempered by frequent inability to achieve full and durable success.

Acute Disease↗
PubMed1990

Scanning electron microscopy analysis of polyethylene oxide hydrogels for blood contact.

Hydrogels are a class of synthetic material, composed of a polymer-water matrix and have been proposed as tissue substitutes and drug delivery vehicles. Polyethylene oxide (PEO) hydrogels were synthesized and used to produce coated wires and conduits for baboon blood compatibility studies. Blood-material interactions were studied both by Scanning Electron Microscopy (SEM) and 111In labeled platelet deposition. SEM processing modifications were first evaluated in order to reduce shrinkage and surface distortion incurred during sample preparation of these high water content materials. Pretreatment with 1% tannic acid reduced bulk shrinkage associated with critical point drying by 10-20%. This effect is small, nevertheless, it prevented major sample disruption. Coated guidewires were exposed to baboon blood for one hour in the inferior vena cava and conduits were placed for either 30 or 60 minutes in an ex vivo femoral arteriovenous shunt. Reference materials included Gore-tex, polyethylene and silica-free polydimethyl siloxane (PDMS). In the guidewire studies, 111In labeled platelet levels were highest on Gore-tex (6568.97 platelets/1000 microns 2) and large thrombotic deposits were well visualized by SEM. Formulations containing PEO had low levels of platelet deposition and little evidence of platelet activation was noted by SEM. Shunt studies demonstrated that materials of high PEO content and molecular weight had the lowest levels of platelet deposition. After 60 minutes of blood flow, mean platelet deposition on PDMS and Gore-tex was 50 and 1000 fold higher than on a network composed of 65% PEO 20,000 (p less than 0.05). SEM confirmed these findings.

Analysis of Variance↗
PubMed1989

Development and evaluation of a new polymeric material for small caliber vascular prostheses.

Polyethylene oxide (PEO), because of its low levels of protein and cellular adsorption, may provide a suitable coating for synthetic small caliber vascular prostheses. PEO/polysiloxane networks were synthesized via an acid-catalyzed epoxy/hydroxyl crosslinking reaction and used to produce conduits with a 4-mm internal diameter. Three networks with nominal PEO molecular weights of 2000, 8000, and 20,000 and all 65% PEO by weight were studied. Blood compatibility was assessed by measuring 111In-platelet and 125I-fibrinogen deposition in a baboon ex vivo shunt, over a 1-hr time period and at a flow rate of 50 ml/min. Differences in material performance were noted particularly after the initial 30-min blood contact period. Materials in the mid and high PEO molecular weight range (8000 and 20,000) had significantly lower levels of platelet adsorption than networks of low PEO molecular weight (2000) at 30 min (P less than 0.005) and 60 min (P less than 0.05). The lowest level of platelet deposition was noted on networks of high PEO molecular weight (20,000). During the observation period, platelet accumulation on this surface was less than one platelet per 1000 microns. Platelet deposition on Gore-Tex was two and three orders of magnitude greater than that on the high molecular weight PEO material at 30 and 60 min, respectively (P less than 0.001). Fibrinogen adsorption was also lower on materials of mid and high PEO molecular weights, when compared with low molecular weight networks (P less than 0.05) and Gore-Tex (P less than 0.05). Scanning electron micrographs confirmed these observations. Overall, platelet and fibrinogen depositions are low for PEO networks, particularly for materials of high PEO molecular weight. This latter observation may be related to increased surface molecular mobility and a relative enhancement of PEO content at the blood-material interface.

Animals↗
PubMed1987

Nontraumatic perforation of the small bowel.

Small intestinal perforation is an infrequent but often fatal complication of a variety of disorders. Treatment of 76 adults with nontraumatic perforation occurring during a 21 year period was reviewed. The majority of perforations were due to mechanical causes, malignancy, and Crohn's disease. An abdominal mass (53 percent, p less than 0.05) and fever (81 percent, p less than 0.01) were most frequently documented in patients with Crohn's disease, whereas a positive result on fecal occult blood testing (77 percent, p less than 0.025) was common in those with malignant perforations. Otherwise, clinical and laboratory manifestations, including radiographic evidence of free air, were inconstant. The overall mortality rate was 29 percent, with 65 (86 percent) of the patients undergoing operation. Survival was independent of diagnostic delay (p greater than 0.10). In general, despite various causes and delays in diagnosis, resection and primary anastomosis remains an effective treatment for perforation of the small bowel.

Adolescent↗
PubMed1985

Colouterine fistula secondary to diverticulitis.

Colouterine fistula complicating diverticulitis is rare. Our experience with two patients, one with chronic vaginal discharge and the other with acute overwhelming sepsis, emphasizes the wide spectrum of clinical presentations that may accompany this entity. In patients with chronic symptoms, surgery is indicated to forestall further local infectious complications, and a single-stage sigmoid resection without hysterectomy may be adequate. If malignancy cannot be excluded, a single-stage en bloc resection of the uterus and colon is the procedure of choice. Hysterectomy may also be mandatory to extirpate a nidus of acute infection. When severe local inflammation or obstruction mandate urgent operation, a two-stage procedure involving resection and end colostomy, followed by reanastomosis at a later time, is safest and most effective.

Aged↗
PubMed1985

Fatal overwhelming postsplenectomy infection.

A total of 776 patients underwent splenectomy at the Massachusetts General Hospital between 1962 and 1972. Follow-up information was obtained on 637 patients (82 percent), including 584 adults and 53 children. There was a total of 4,837 person-years of follow-up with a mean observation interval of 8.4 years. Four cases of fatal overwhelming postsplenectomy infection were identified. In our pediatric population, the incidence of fatal overwhelming postsplenectomy infection was 3.77 percent, which was significantly higher than the incidence of 0.34 percent in our asplenic adults. Overwhelming postsplenectomy infection is a unique clinical entity distinguishable from other infections. It may occur during the lifetime of any asplenic patient and especially in those patients who have had a splenectomy in childhood. In asplenic adults, the incidence is low. The aggressive approach to splenic preservation in the adult should be tempered by these results.

Adolescent↗
PubMed1985

Traumatic pseudoaneurysms of the abdominal aorta.

The present report describes a patient with a traumatic pseudoaneurysm of the abdominal aorta and reviews the past literature. Traumatic aneurysms occur in a young patient population, and may present as late as 27 years after initial injury. Sonography and computed body tomograms (CBT) with contrast are especially useful screening tools. However, aortography is mandatory for complete preoperative evaluation. Aortic repair may require either suture aortorrhaphy, patch aortoplasty or graft replacement. Adequate exploration and repair at the time of initial injury will prevent pseudoaneurysm formation and the potential of delayed aortic rupture.

Adolescent↗
PubMedDate not supplied

High-resolution analysis of engineered type I collagen nanofibers by electron microscopy.

Collagen nanofibers were generated at ambient temperature and pressure by electrospinning a 1 wt% solution of type I collagen and polyethylene oxide. Products were imaged with high-resolution scanning electron microscopy (HRSEM) at medium (approximately 30,000 x) and high magnifications (approximately 100,000 x) and with transmission electron microscopy (TEM). The capacity to produce collagen nanofibers may lead to the generation of extracellular matrix-based fabrics with applications in the fields of wound healing and tissue engineering.

Collagen Type I↗