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Biomedical subjects

R G Atnip

Publications and source records attributed to R G Atnip.

16 recordsLinked to original sources
PubMed1995

Renal revascularization in patients on dialysis.

Five patients requiring dialysis for acute pulmonary edema and uremia from severe renal artery occlusive disease underwent surgical revascularization. Three patients with oliguria had excellent outcomes and remain dialysis-independent as long as twenty-four months following operation (mean serum creatinine 2.0 mg/dl). The two patients who were anuric both had technically successful operations but remained dialysis-dependent. Diagnostic evaluation of the azotemic patient suspected to have renal arterial occlusive disease should include a history and physical examination, urinalysis, renal ultrasound, and duplex scan of the renal arteries. In appropriate patients, arteriography should then be considered if other diagnoses appear unlikely. This algorithm may help identify those patients who might benefit from renal revascularization. It appears that oliguria rather than anuria and the angiographic demonstration of a patent distal vessel and nephrogram suggest a better functional outcome after revascularization. Unfortunately, the response to surgery cannot be reliably predicted and patient selection remains a challenge, but retrieval of renal function can be achieved in some cases even if patients are already being hemodialyzed.

Acute Kidney Injury↗
PubMed1994

Validation of air plethysmography, photoplethysmography, and duplex ultrasonography in the evaluation of severe venous stasis.

PURPOSE: The purpose of this study was to validate the diagnostic capabilities of the most commonly used noninvasive modalities for evaluation of chronic venous insufficiency. METHODS: Twenty limbs in 20 patients were studied with air plethysmography (APG), photoplethysmography (PPG), and duplex ultrasonography. Ten limbs (group 1) were clinically without any venous disease. Group 2 consisted of 10 limbs with severe, class 3 venous stasis. Duplex ultrasonography, complemented with Doppler color-flow imaging was used to examine the superficial and deep venous systems to identify reflux. RESULTS: Ultrasonography identified deep venous reflux in eight of 10 limbs in group 2. Severe superficial reflux was identified in the two remaining limbs. Seven limbs with deep reflux also demonstrated severe superficial reflux. Superficial venous reflux was identified in one leg in group 1. APG accurately separated normal limbs from those with reflux. Parameters that were significantly different (p < 0.05) between the two groups were the venous filling index, (group 1 = 1.37 +/- 1.16 ml/sec, group 2 = 29.5 +/- 6.2 ml/sec.), venous volume (group 1 = 107 +/- 10.1 ml, group 2 = 220 +/- 22.5 ml), ejection fraction (group 1 = 52.5% +/- 2.3%, group 2 = 32.5% +2- 4.6%), and residual volume fraction (group 1 = 21.4 +/- 2.0%, group 2 = 52.1% +/- 2.5%). PPG refill times were significantly shortened in group 2 versus those of group 1 (6.4 +/- 0.89 sec vs 20.2 +/- 1.1 sec). The sensitivity of PPG refill times to identify reflux was 100%, but the specificity was only 60%, whereas the sensitivity and specificity for the residual volume fraction was 100%. The venous filling index was able to identify reflux and determine whether only superficial reflux was present with a sensitivity of 100% and a specificity of 90%. The kappa coefficient of agreement between duplex scanning and APG was 0.83, whereas between duplex and PPG it was only 0.47. CONCLUSION: APG accurately identifies limbs with and without venous reflux when compared with duplex ultrasonography. APG is a better method of evaluating clinically significant venous reflux than PPG. PPG is a sensitive method of detecting reflux, but the specificity is poor, and PPG refill times cannot accurately predict the location of reflux. The combination of APG and duplex ultrasonography provides the best means of assessing venous reflux.

Adolescent↗
PubMed1994

Relative risks of limb revascularization and amputation in the modern era.

A retrospective review of 266 patients undergoing infrainguinal revascularization for limb salvage and/or major amputation (transmetatarsal, below-knee or above-knee) from 1984 to 1990 was conducted to determine comprehensive procedure-specific 30-day operative morbidity and mortality rates. Some 211 patients underwent 295 infrainguinal vascular reconstructions (195 primary and 100 secondary reconstructions). There were 122 major amputations in 98 patients (29 above-knee, 70 below-knee and 23 transmetatarsal). Most amputations were performed in patients with unreconstructable vascular disease, including 39 patients (41 extremities) with failed infrainguinal reconstruction. Procedure-specific morbidity and mortality rates were 48 and 2% for primary revascularization, 35 and 2% for secondary revascularization and 37 and 4%, for amputation, respectively. The difference in mortality between revascularization and amputation approached but did not achieve statistical significance. Cardiac, graft and wound complications were the major causes of morbidity in all groups. Nine of the 12 deaths were of cardiac etiology. Revascularization can be performed in almost all patients with advanced limb ischemia, with a mortality rate equivalent to, or perhaps lower than, that of amputation. When limb amputation is required, it can be performed with a mortality rate remarkably lower than that described in the older literature.

Acute Disease↗
PubMed1992

Evaluation of celiac and mesenteric vascular disease with duplex ultrasonography.

A retrospective study of 25 patients was performed to evaluate the applicability of duplex ultrasonography to the celiac and superior mesenteric circulation. Lateral contrast aortograms were compared to the pulsed-Doppler spectral data from duplex examinations in fasting subjects. A significant correlation was identified between the celiac-aortic diastolic ratio and the degree of stenosis measured angiographically, but such a relationship could not be established for the superior mesenteric artery. These data suggest that duplex ultrasonography may not be a reliable screening test for mesenteric vascular disease.

Angiography↗
PubMed1991

Crossover ilioprofunda reconstruction: an expanded role for obturator foramen bypass.

The standard obturator foramen bypass extends from the aorta or iliac artery to the ipsilateral superficial femoral or popliteal artery. This operation has been both effective and versatile as an indirect bypass procedure for circumventing difficult vascular problems in the femoral triangle. A case is presented of a patient whose limb was salvaged by an obturator foramen bypass from the contralateral iliac artery to the profunda femoris artery. This unique case is compared to other published cases to emphasize the potential advantages of the profunda femoris as the preferred graft outflow in selected cases of arterial reconstruction through the obturator foramen.

Aged↗
PubMed1990

Ischemic gastroparesis: resolution after revascularization.

Patients with chronic nausea and vomiting frequently present challenging diagnostic and therapeutic problems. In such patients, gastroparesis of unknown cause, or "idiopathic" gastroparesis, may be the only objective finding. Two middle-aged women with nausea, vomiting, and weight loss of 10 and 26 kg over 6 and 18 months, respectively, were evaluated. Routine laboratory and barium study results were normal. Solid-phase gastric emptying studies showed severe gastroparesis in both patients. Upper endoscopies excluded gastric outlet obstruction. Gastric dysrhythmias (4-cpm and 1-cpm patterns) were recorded using cutaneous electrodes. An abdominal bruit was ascultated in one patient. Abdominal arteriograms in both patients showed total occlusion of all three major mesenteric vessels with collaterals supplied via hemorrhoidal arteries. Bypass grafting procedures of the celiac and superior mesenteric arteries in one patient and of the celiac artery in the other patient were performed. Six months after mesenteric artery revascularization, upper gastrointestinal symptoms had resolved and original weights were regained. Furthermore, normal 3-cpm gastric myoelectrical activity and normal gastric emptying of solids were restored in both patients. In these patients, chronic mesenteric ischemia resulted in a novel and reversible cause of gastroparesis, gastric dysrhythmias, and accompanying symptoms.

Blood Vessel Prosthesis↗
PubMed1990

Wound complications of autogenous subcutaneous infrainguinal arterial bypass surgery: predisposing factors and management.

To identify factors predisposing to wound infection and necrosis complicating in situ or other subcutaneous autogenous lower extremity vein bypass procedures, we retrospectively analyzed all such cases performed in our hospital between July 1983 and July 1988. Among 163 subcutaneous autogenous bypass grafts, wound complications developed in 28 (17%). According to progressive depth of involvement as defined in the text, 10 patients had grade I complications, six had grade II, and 12 had grade III complications with threatened or actual graft exposure. Factors significantly associated with wound morbidity were female gender, chronic steroid therapy, in situ bypass grafting, use of continuous incision (all p less than or equal to 0.05, chi square); diabetes mellitus, ipsilateral limb ulcer, limb salvage indication (all p less than 0.01); and bypass grafting to the dorsalis pedis artery (p less than 0.02). A logistic regression analysis identified four factors (in situ bypass grafting, steroid therapy, ipsilateral ulcer, and dorsalis pedis bypass grafting) that predicted a cumulatively increasing risk of wound complications, and in whose absence wound complications were rare. Grade I and II complications responded to standard regimens of wound care and intravenous antibiotics without loss of any graft or limb. In spite of aggressive efforts to provide secondary soft tissue coverage, grade III complications led directly to four major amputations and one death. Measures to prevent these morbid sequelae must include preoperative control of infection in the ischemic foot and meticulous attention to operative technique.

Aged↗
PubMed1990

Combined aortic and visceral arterial reconstruction: risks and results.

The indications, morbidity, and efficacy of combined reconstruction of the abdominal aorta and visceral arteries (renal and superior mesenteric; excluding suprarenal aortic aneurysms) were analyzed retrospectively in 29 consecutive patients who underwent surgery from June 1984 through February 1990. Seventeen men and 12 women ages 32 to 76 years (mean, 66 years) were studied. Follow-up was complete in all patients to either death or calendar year 1989 to 1990 (mean, 31.9 months; range, 2 to 66 months). All patients underwent bypass of angiographically proven severe lesions of one renal artery (19 patients), both renal arteries (8 patients), or the superior mesenteric artery and renal arteries (2 patients), in concert with synthetic distal aortic replacement for occlusive disease (10 patients) or aneurysm (19 patients). Indications for renal artery repair included severe hypertension in 13 patients, ischemic renal insufficiency in 8 patients, and lesion morphology alone in 8 patients. Operative mortality rate was 3 of 29 (10.3%), and each death was the result of multisystem organ failure. Nonfatal complications occurred in 11 of the 26 survivors (42%), and this group differed significantly from the uncomplicated 15 patients only in having a higher mean preoperative serum creatinine (2.5 +/- 1.1 mg/dl vs 1.6 +/- 0.9 mg/dl, p = 0.04, t test). The mortality rate of patients with preoperative serum creatinine greater than or equal to 2.0 mg/dl, was 15.4% (2/13 patients), compared to 6.2% (1/16) in patients with creatinine less than 2.0 mg/dl. Three late deaths occurred (2 stroke, 1 cancer). Hypertension control improved in 64% of patients overall, and in 7 of 9 patients whose major operative indication was renovascular hypertension. Renal function remained stable or improved in 12 of 15 patients (80%) with renal insufficiency, but 3 patients progressed to require dialysis. Long-term graft patency was demonstrated by angiography or on duplex scan in all studied survivors (21 patients). Although operative risks are clearly increased compared to less complex vascular procedures, careful patient selection and management will yield a favorable outcome in most patients with such combined lesions.

Adult↗
PubMed1990

A rational approach to recurrent carotid stenosis.

To further characterize the incidence and morbidity of recurrent carotid stenosis, we reviewed 184 consecutive carotid endarterectomies performed in a university hospital between August 1983 and January 1988, in patients followed after operation with serial duplex ultrasonography. Recurrent stenosis of greater than 50% diameter reduction developed in eleven arteries (6.0%) at a mean interval of 10.2 +/- 7.8 months. Three of the eleven (1.6% of the total) had associated transient ischemic attack, and none had strokes. Restenosis was significantly more frequent in diabetic patients than in nondiabetic patients (13.3% vs 4.5%; p less than 0.05); and among patients whose primary stenoses had been symptomatic compared to asymptomatic (11.0% vs 1.5%; p less than 0.02). No statistically significant association with restenosis could be established for gender, hypertension, or smoking. Completion angiography and/or Doppler spectral analysis had been performed, and results were normal at the primary operation in 10 of the 11 patients. Only six of 184 arteries (3.3%) had vein patch closure, but none of these restenosed. Uneventful reoperation with patch closure was performed in three patients with transient ischemic attacks and two with preocclusive restenoses. Lesions were myointimal hyperplasia in four and atheroma in one. Three of the unoperated restenoses have shown regression on duplex scanning, but a fourth progressed to asymptomatic occlusion. Carotid restenosis is uncommon, even without routine use of vein patch angioplasty. Reoperation should be reserved for patients with associated symptoms or greater than 80% restenosis.

Carotid Artery Diseases↗
PubMed1989

Mycotic aneurysms of the suprarenal abdominal aorta: prolonged survival after in situ aortic and visceral reconstruction.

Necrotizing infection of the arterial wall causes rupture and false ("mycotic") aneurysm formation, with a very poor prognosis if untreated. Cure can be achieved by surgical drainage and debridement, with restoration of arterial continuity through uncontaminated tissues. The dilemma of applying these principles to the treatment of mycotic aneurysms of the suprarenal aorta is that no remote or extraanatomic routes are available to maintain perfusion to the viscera. We report the first case of Klebsiella suprarenal mycotic aortic aneurysm successfully treated with in situ prosthetic reconstruction of the aorta and visceral arteries, and we have reviewed the 21 other suprarenal mycotic aortic aneurysms reported in the English-language literature. Repair was performed in 20 of the 22 cases, with in situ prosthetic reconstruction performed in 18. Prolonged survival has been achieved in 16 patients after in situ repair. No long-term survival has been reported after extraanatomic reconstruction of the aorta and visceral arteries in patients with such aneurysms. We conclude that in situ prosthetic reconstruction, accompanied by thorough drainage and debridement, prolonged parenteral antibiotic therapy, and permanent suppressive oral antibiotics, offers the best chance for survival in these patients.

Aneurysm, Infected↗
PubMed1986

Use of the splenic and hepatic arteries for renal revascularization.

During a 16-year period at the Massachusetts General Hospital 77 patients underwent 79 procedures (29 hepatorenal bypasses, 50 splenorenal arterial anastomoses) for treatment of renovascular hypertension, renal preservation, or both. The procedure was chosen primarily to avoid a diseased or scarred aorta in 41, to allow a staged approach to bilateral renal artery stenoses or multiple vascular lesions in 17, as a "lesser operation" for five poor-risk patients, for complex problems including trauma, mycotic aneurysm, aortic dissection, thoracoabdominal aneurysm, and renal artery aneurysm in five, and as the procedure of choice in 11 patients. The perioperative mortality rate was 6% for the 77 patients studied. No hepatic dysfunction was seen. Deterioration of renal function occurred on three occasions but only in patients with bilateral simultaneous repair. Cure or improvement of hypertension was achieved in 52 of 63 patients and renal function preserved or improved in 67 of 77 patients. Long-term functional results remain good during follow-up periods up to 14 years. Our experience indicates that use of the hepatic or splenic artery may provide a safe and largely successful alternative for renal revascularization in selected circumstances.

Follow-Up Studies↗
PubMed1983

Skin coverage.

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Artificial Organs↗
PubMedDate not supplied

Recurrent pulmonary embolism after inferior vena caval interruption with a Greenfield filter.

Twenty-six patients have undergone inferior vena caval interruption with a Greenfield filter. One patient (3.8%) developed a fatal, recurrent pulmonary embolism. Postmortem examination documented the presence of thrombus within the filter, proximal extension of thrombus beyond the filter apex, and fresh pulmonary emboli. In a combined series of 556 patients, 12 patients (2.2%) developed recurrent pulmonary emboli, 2 (0.36%) of which were fatal. Including case reports, 18 patients have had documented recurrent pulmonary emboli following Greenfield filter insertion. In 4 patients, the recurrent embolism was fatal. Six (60%) of 10 patients had a concomitant malignancy. A work-up and treatment plan for patients having recurrent pulmonary emboli after the insertion of a Greenfield vena caval filter is proposed.

Hemofiltration↗
PubMedDate not supplied

Thrombolytic therapy and balloon catheter thrombectomy in experimental femoral artery thrombosis: effect on arterial wall morphology.

PURPOSE: To determine vessel wall architectural changes after lytic therapy and balloon catheter thrombectomy in experimentally thrombosed arteries. MATERIALS AND METHODS: Bilateral 5-cm femoral artery occlusions were created by ligation in 14 dogs. Two dogs served as controls, and 12 animals underwent balloon catheter thrombectomy on the left and lytic therapy with urokinase on the right either 24 hours (group 1, n = 6) or 7 days (group 2, n = 6) after creation of the occlusion. After treatment, the area of thrombosis was subjected to light and scanning electron microscopy. RESULTS: The IEL was intact in all lysed arteries. IEL fractures were present in 11 of 12 arteries treated with thrombectomy. For group 1 arteries, average luminal area after thrombectomy was 5.63 mm2 +/- 0.66 versus 1.94 mm2 +/- 0.7 after lytic therapy (P < .007). Mean control artery luminal area was 2.86 mm2 +/- 0.52. Similar differences were found in group 2 arteries. With lytic therapy, scanning electron microscopy grading revealed surfaces to be intact in group 1, but moderate injury was exhibited in group 2. All arteries treated with thrombectomy had severe injury. CONCLUSIONS: Lysis of acute thrombi (group 1) preserved arterial wall architecture, with an intact IEL and no endothelial injury. Lysis of chronic thrombi (group 2) was associated with mild to moderate injury. Catheter thrombectomy caused severe injury regardless of the time of intervention. These results may help explain the poor long-term patency observed after these interventions.

Animals↗