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G H Meier

Publications and source records attributed to G H Meier.

29 records · Page 2Linked to original sources
PubMed1993

Captopril renal scintigraphy: a new standard for predicting outcome after renal revascularization.

PURPOSE: Captopril renal scintigraphy (CRS) is a nuclear medicine technique for evaluating each kidney independently for changes in glomerular filtration rate and perfusion induced by captopril-associated alterations in vascular tone. This study was undertaken to determine the role of CRS in predicting the response to renal revascularization. METHODS: The study group consisted of all patients who underwent preintervention CRS and arteriography, followed by renal revascularization performed between December 1987 and February 1992. After cessation of administration of angiotensin-converting enzyme inhibitors for 48 hours, a standard renogram was obtained, a 50 mg dose of captopril was given, and a second renogram was obtained. A captopril-induced change in the renogram was present when a normal pre-captopril renogram became abnormal after captopril administration. An abnormal baseline scan by definition cannot have a captopril-induced change. Blood pressure before revascularization was compared with blood pressure at 3 to 6 months after the procedure according to American Heart Association criteria for hypertension response. RESULTS: Fifty patients received renal revascularization by operation (28 patients) or balloon angioplasty (22 patients). Preoperative captopril-induced changes were present in 29 of the 50 patients. Among the 29 patients with captopril-induced changes, hypertension was cured or improved in 26. When captopril-induced changes were not present, only one of 21 patients improved (p < 0.00001). CONCLUSION: On the basis of these data, CRS appears to reliably predict hypertension response to revascularization in patients with renovascular disease.

Adult↗
PubMed1991

Simplified captopril renography in diagnosis and treatment of renal artery stenosis.

To improve the diagnosis and forecast the response to surgery or renal angioplasty in patients with hypertension and renal artery stenosis, we employed a simplified captopril renography protocol in conjunction with renal arteriography in 94 clinically selected patients. Fifty hypertensive patients (group 1) with a high clinical likelihood of renovascular hypertension were evaluated using a simplified captopril renography protocol and renal angiography on the arterial side. Criteria for normal captopril renal scintigrams were established based on this original cohort and validated in an additional 44 clinically comparable patients (group 2). Renal revascularization or nephrectomy was performed in 39 patients, and success of the procedure was determined in the 34 patients for whom 3-month follow-up was available. In the 94 patients, 44 (47%) had renal artery stenosis. Simplified captopril renography was 91% sensitive and 94% specific in identifying or excluding renal artery stenosis in the combined group, with no difference in the diagnostic utility between groups 1 and 2, or in those with renal insufficiency (n = 38) or those with bilateral disease (n = 17). Scintigraphic abnormalities induced by captopril were strongly associated with cure or improvement in blood pressure control following revascularization or nephrectomy (15 of 18), while the lack of captopril-induced changes was associated with failure of such intervention (13 of 16) (p = 0.0004). We conclude that simplified captopril renography is highly sensitive and specific in the diagnosis of renal artery stenosis in a clinically selected high-risk population and that the test accurately predicts the success or failure of therapeutic intervention.

Aged↗
PubMed1990

Captopril renal scintigraphy--an advance in the detection and treatment of renovascular hypertension.

Despite the risks associated with renovascular hypertension and the durable benefits of revascularization, the detection of patients with renovascular hypertension and the selection of those who will benefit from interventional therapy remains a challenge. We have previously documented the reliability of captopril renal scintigraphy in predicting angiographically significant renal artery stenosis in patients suspected of having renovascular hypertension. In the present study we report our recent experience with this noninvasive technique in predicting outcome after revascularization. Captopril renal scintigraphy involves the administration of 50 mg of captopril 3 hours after a baseline technitium-99m diethylenetriaminepentaacetic acid renal scan and 1 hour before a repeat captopril renal scintigraphy scan. Nineteen of the last 70 patients with clinically suspected renovascular hypertension undergoing captopril renal scintigraphy had abnormal renal scan outcomes, and 17 had a decrease in flow or function after captopril (positive captopril renal scintigraphy). Eight of these 17 with abnormal findings on captopril renal scintigraphy underwent revascularization, and the hypertension was cured or improved in six of the eight: two of three after surgical bypass grafting and four of five after angioplasty. In the seven surviving patients with abnormal renal scan results but no change with captopril (negative captopril renal scintigraphy), improvement in hypertension after treatment occurred in only one: one of two after nephrectomy, zero of three after bypass surgery, and zero of two after angioplasty (p less than 0.05). We conclude that captopril renal scintigraphy is an accurate predictor of hypertension response to revascularization. Further evaluation of this new noninvasive technique for assessing patients with suspected renovascular hypertension appears warranted.

Aged↗
PubMed1989

Endoscopic sclerotherapy: a risk factor for splanchnic venous thrombosis.

Endoscopic sclerotherapy has been widely advocated as primary therapy for patients surviving hemorrhage from esophageal varices. The potential for endoscopic sclerotherapy to limit subsequent surgical options remains unclear. The following study was undertaken to assess the endoscopic sclerotherapy-related incidence of splanchnic venous thrombosis in patients undergoing surgery for variceal bleeding. We retrospectively identified 27 patients who underwent portosystemic shunting after an episode of variceal hemorrhage documented by endoscopic examination. Eleven patients underwent endoscopic sclerotherapy before portosystemic surgery for shunting. Among the patients undergoing prior endoscopic sclerotherapy, 6/11 had partial splanchnic venous thrombosis at surgery compared with 2/16 in the non-endoscopic sclerotherapy group. This difference was statistically significant. Only one of the eight patients with splenic or portal vein thrombosis detected at surgery showed signs of the condition when an angiograph was performed. Endoscopic sclerotherapy appears to impose a significant risk for splanchnic venous thrombosis. This complication, not reliably detected by angiographic means, may limit the operative options and long-term outcomes of patients in whom endoscopic sclerotherapy fails.

Endoscopy↗
PubMed1987

Reoperation for aortofemoral graft limb occlusion: optimal methods and long-term results.

To determine optimal methods of reoperation, experience with 157 secondary procedures for unilateral aortofemoral graft limb occlusion in 110 patients during a 16-year period was reviewed. In earlier years, inflow was reestablished by direct replacement of the graft limb or entire graft (11%); more recently, graft limb thrombectomy has been used most frequently (68%) with equal success, durability, and less morbidity. Femorofemoral grafts from the patent contralateral graft limb were employed in 18% of patients, usually those in whom thrombectomy was not attempted. Thrombolytic therapy (3%) appears to offer little advantage, is time-consuming, and occasionally causes significant complications. In addition to reestablishment of inflow, most patients also required revision of the femoral anastomosis to improve profunda femoris runoff; this was usually best accomplished by short segmental extension of the graft limb to the more distal deep femoral artery. Concomitant femoropopliteal bypass was done in 32% of patients and is indicated when preoperative angiography or specific intraoperative findings suggest inadequate profunda femoris outflow. An aggressive approach to reoperation appeared justified by long-term results (mean follow-up 37 months). Despite the need for repetitive reoperation in 26% of patients (two to five reoperations), graft limb patency was ultimately maintained in 78% and limb salvage achieved in 67% of patients, with an operative mortality rate of only 1.9%.

Adult↗
PubMed1987

Extending the limits of limb salvage.

Over the past several years a combination of diverse steps has culminated in a significant improvement in our ability to save ischemic extremities. Encompassing all phases of vascular surgery, these advances in diagnosis, therapy, and long-term management are outlined. These and future improvements hold promise for extended limb salvage with lower mortality than previously considered possible.

Angioplasty, Balloon↗
PubMed1979

Systemic air embolization from penetrating lung injury.

This study evaluates the role of increased intratracheal pressure in developing systemic air embolization. Twenty healthy mongrel dogs were monitored for air embolization, both by means of an extracorporeal arteriovenous shunt constructed from transparent plastic tubing for visualization of air emboli and by means of a Doppler flow probe implanted at the root of the aorta. Systemic arterial, left atrial, intratracheal, and intrapleural pressures were recorded. In 10 of the dogs, a penetrating wound of the lung 1 cm wide by 4 cm deep was produced; in 5 the chest was left open and in 5 the chest was closed. The remaining 10 dogs served as controls (with no wound of the lung); in 5 the chest was left open and in the other 5 the chest was closed. No air embolization occurred in any animals at intratracheal pressures less than 65 mm Hg. However, systemic air embolization occurred in every dog in all groups upon hyperinflation of the lung above 65 mm Hg. The control groups differed from the groups with penetrating wound only in the quantity of embolized air. This study suggests that hyperinflation of the lung to an intratracheal pressure above 65 mm Hg results in systemic air embolization and that the presence of a penetrating wound of the lung at such intratracheal pressure predisposes to a greater quantity of air embolization.

Animals↗
PubMedDate not supplied

Management of large high-flow arteriovenous malformations of the shoulder and upper extremity with transcatheter embolotherapy.

PURPOSE: To evaluate the efficacy of transcatheter embolization of arteriovenous malformations (AVMs) of the shoulder and upper extremity. PATIENTS AND METHODS: Four men with large AVMs of the shoulder and upper extremity were treated with transcatheter arterial embolization. Symptoms included high cardiac output, pain, paresthesias, and disfigurement. Each patient underwent multiple sessions of embolotherapy. RESULTS: In two patients there was no decrease in cardiac output. In three patients, no permanent decrease in AVM size or resolution of pain was achieved. Two patients experienced postembolization skin necrosis, and one experienced permanent radial neuropathy. CONCLUSIONS: Large, high-flow AVMs in the shoulder and upper extremity may be relatively refractory to intravascular treatment because of the diffuse involvement of the soft tissues by the AVM and the lack of a well-defined nidus. Transcatheter embolotherapy in these lesions should be reserved for patients undergoing resection to help decrease intraoperative bleeding.

Adult↗
PubMedDate not supplied

Medical Grand Rounds: refractory hypertension and renal insufficiency in a patient with renal artery stenosis.

Renal artery stenosis has become increasingly common as a cause of refractory hypertension and renal insufficiency. There is a high prevalence of bilateral disease and the lesions tend to progress over time. Newer, less invasive, imaging modalities such as doppler ultrasound, magnetic resonance angiography, and spiral CT scanning are evolving technologies in the diagnosis of renal artery stenosis. Advances in surgical technique, particularly the development of extra-anatomical procedures such as spleno-renal and hepato-renal by pass, have significantly lowered surgical morbidity and mortality and provides revascularization options for patients with complex vascular disease that would previously not have been considered because of their high surgical risk. Improvements in angioplasty technique and the use of stents are broadening the types of lesions that can be successfully approached with these techniques and may be particularly helpful for patients with more severe cardiac or cerebrovascular disease. The benefits of revascularization may be even greater for preservation of renal function than for control of blood pressure in properly selected patients. It is difficult to predict which patients will benefit from surgical revascularization versus medical management of RAS. Knowledge of the progressive nature of RAS, the high prevalence of bilateral disease, and the clinical characteristics that correlate with progression (e.g., decreasing renal size) are helpful in guiding clinical decisions regarding intervention. Additional studies to determine the predictive value of non-invasive tests such as CRS, doppler ultrasound before and after administration of angiotensin converting enzyme inhibitors, and other tests, are needed to assist the clinician in identifying who will benefit most from revascularization both in terms of renal function and blood pressure control.

Aged↗