Search PubMed⌕ Search

Biomedical subjects

D B Williams

Publications and source records attributed to D B Williams.

At least 127 records · Page 7Linked to original sources
PubMed1984

Management of patients with carotid bruit undergoing cardiopulmonary bypass.

During a 31 month period, 1,433 consecutive patients undergoing cardiac procedures were screened for carotid bruit. A total of 94 patients with carotid bruit were identified who had ultrasonic carotid duplex scans. Nine patients had a history of transient ischemic attack, carotid bruit, and reduction in internal carotid artery diameter by greater than or equal to 50% according to ultrasonic carotid duplex scanning. All nine patients underwent carotid angiography followed by thromboendarterectomy prior to or simultaneous with cardiopulmonary bypass. There was one neurological complication leading to death in this subset. Sixteen patients with asymptomatic carotid bruit had ultrasonic carotid duplex scanning revealing an internal carotid artery lesion of greater than or equal to 50% but did not undergo arteriography or thromboendarterectomy prior to the cardiac procedure. Perfusion pressure was maintained at greater than or equal to 70 mm Hg during bypass. There were no focal neurological events in this subset. Sixty-six patients with internal carotid artery stenosis of less than 50% diameter reduction and asymptomatic bruits had no further work-up or modification in perfusion technique, and there were no focal neurological events in this group. Thus there were no focal neurological events in any of the 82 patients with asymptomatic carotid bruit. An additional group of three patients with a previous stroke and internal carotid artery occlusion by ultrasonic carotid duplex scanning had transient exacerbation of neurological symptoms after cardiopulmonary bypass. The remaining 1,339 patients without carotid bruit had nine (0.7%) focal neurological events postoperatively. We believe that asymptomatic patients with or without hemodynamically significant stenosis can safely undergo cardiopulmonary bypass procedures without carotid thromboendarterectomy. Patients with asymptomatic bruits can be safely screened with ultrasonic carotid duplex scanning and do not require arteriography prior to cardiopulmonary bypass.

Auscultation↗
PubMed1983

Postinfarction angina: results of early revascularization.

To assess the efficacy of surgical revascularization for postinfarction angina within 30 days of acute infarction, the clinical course of 103 patients treated surgically from January 1979 to July 1982 was reviewed. There were 84 men (82%) and 19 women (18%) with a mean age of 58 years (range 34 to 80). Group A (11 patients) underwent surgery within 24 hours of infarction, Group B (21 patients) within 7 days and Group C (71 patients) within 30 days. Eighty-four patients (82%) had subendocardial infarctions and 19 patients (18%) had transmural infarction. Transmural infarction was more common in patients in Group A (36%) than in those in either Group B (19%) or Group C (15%). There were two deaths, both in Group C (1.9%), within 30 days of surgery. The use of intraaortic balloon or inotropic support and the occurrence of major arrhythmias or perioperative infarction was noted in 30 patients (29%) (64% in Group A, 33% in Group B and 18% in Group C). The average time in the intensive care unit was 3.2 days, with an average total hospital stay after surgery of 8.3 days. Late follow-up (mean 15.4 months, range 1 to 39) is complete for 97 patients (97%). There were no late myocardial infarctions and 93 patients (96%) were essentially free of angina. The only late death (1.0%) was caused by septicemia from delayed sternal wound infection. This study suggests that myocardial revascularization within the first 30 days after myocardial infarction can be accomplished with an acceptable operative mortality in selected patients with postinfarction angina refractory to medical management.

Adult↗
PubMed1983

Influence of propranolol on supraventricular tachycardia early after coronary artery revascularization. A randomized trial.

A total of 116 patients undergoing coronary revascularization were randomized preoperatively in a double-blind manner to receive 80 mg daily of propranolol or placebo in the postoperative period. Preoperatively, all patients had been receiving at least 80 mg of propranolol a day to the time of the operation. In addition, all patients had a left ventricular ejection fraction of 0.4 or more, no history of supraventricular tachyarrhythmia (SVT), and no need of digitalis preparations or other antiarrhythmic drugs. All patients were monitored for 5 days and propranolol or placebo was started 24 hours postoperatively. SVT was documented with biatrial electrograms in all cases. Study groups were similar in postoperative creatine kinase MB levels and postoperative weight gain, but the placebo group tended to be older and have more grafts per patient. Seven patients randomized were dropped from the study, two with perioperative infarction, four with persistent ventricular arrhythmias necessitating quinidine or procainamide, and one with persistent postoperative hypotension (placebo). There were no significant differences in the incidence of postoperative SVT in these two groups: 13.2% in the propranolol group and 16.1% in the placebo group. We conclude that 80 mg daily of propranolol given postoperatively to patients undergoing coronary revascularization does not effectively reduce the incidence of SVT.

Clinical Trials as Topic↗
PubMed1982

The hemodynamic response to dopamine and nitroprusside following right atrium-pulmonary artery bypass (Fontan procedure).

Cardiac output is critically dependent upon pulmonary vascular resistance after right atrium-pulmonary artery bypass (Fontan procedure), since there is no pulmonary ventricle in the circulation. Inotropic agents, including dopamine, may increase pulmonary vascular resistance and, therefore, might have an adverse effect on cardiac output. The present study determined the hemodynamic responses to dopamine and nitroprusside of 9 patients following right atrium-pulmonary artery bypass. Particular attention was given to effects on cardiac output (CI), pulmonary vascular resistance, and right atrial pressure (RAP). Baseline hemodynamic data were measured without drugs, with dopamine at 7.5 micrograms/kg/min, with sodium nitroprusside up to 5.0 micrograms/kg/min, and with a combination of dopamine, 7.5 micrograms/kg/min, and sodium nitroprusside, 1.0 micrograms/kg/min. Right and left atrial pressures (LAP), mean arterial blood pressure (BP), heart rate (HR), and CI were measured. Stroke volume index and pulmonary arteriolar resistance index were calculated. The increase in CI from baseline (1.98 +/- 0.86 liters per minute) was significant for infusions of dopamine (2.75 +/- 1.05, p less than 0.001), sodium nitroprusside (2.57 +/- 0.78, p less than 0.001), and both drugs (2.74 +/- 0.84, p less than 0.001). The increased CI was achieved primarily by a significant increase in HR with dopamine and by an increase in stroke volume index with sodium nitroprusside. With a similar increment in CI, the RAP was significantly decreased from baseline (21 +/- 4 torr) with sodium nitroprusside (15 +/- 3, p less than 0.001) but was unchanged with dopamine. Pulmonary arteriolar resistance index decreased significantly from baseline (375 +/- 230 dynes sec cm-5/m2) with sodium nitroprusside (169 +/- 132, p less than 0.001), and, interestingly, with dopamine as well (273 +/- 165, p less than 0.05). Both dopamine and sodium nitroprusside in these dosages have favorable effects on CI and pulmonary arteriolar resistance index in patients after right atrium-pulmonary artery bypass. Whenever feasible, sodium nitroprusside is preferred for increasing CI after such a bypass procedure, since lower RAP decreases the severity of fluid retention, ascites, and chest tube drainage.

Adolescent↗
PubMed1982

Spontaneous thrombosis of a giant intracranial aneurysm and ipsilateral internal carotid artery. Case report.

Computerized tomography revealed a thrombosed giant intracavernous carotid aneurysm in a man who presented with ophthalmoplegia and headache. Angiography confirmed complete aneurysmal thrombosis and also revealed complete occlusion of the ipsilateral internal carotid artery. Aneurysmotomy and thrombectomy produced substantial reduction in mass effect, with symptomatic improvement. The spontaneous thrombosis of giant intracranial aneurysms is discussed.

Adult↗
PubMed1982

Observations on esophageal blood supply.

The recent surgical treatment of two patients with relatively complex esophageal problems is described. In one patient, a long segment of proximal intrathoracic esophagus was mobilized during the course of surgery, and it was noted that the esophagus was viable and had a good blood supply at the distal margin of resection. In the other, the entire cervical and intrathoracic esophagus remained viable after mobilization. The obvious viability of these long esophageal segments detached from the segmental blood supply prompted us to preserve and use them in reconstruction. These observations suggest that there is a rich intramural arterial and venous network complementing the segmental blood supply of the esophagus. Although previous studies have clearly demonstrated a rich intramural esophageal vasculature, to the best of our knowledge it had not been clearly demonstrated that such lengths of esophagus could be mobilized from their segmental blood supply and remain viable. The details of these two cases are presented and discussed to document this observation and the manner in which it was possible to modify the esophageal reconstruction favorably by the use of the mobilized segment of esophagus.

Cervical Vertebrae↗
PubMed1982

Cardiac fibroma: long-term survival after excision.

Four patients have had operation at the Mayo Clinic for a cardiac fibroma and all survived. Three patients have an excellent clinical result and are free of tumor 1 year, 13 years, and 17 years postoperatively. The fourth shows radiographic evidence of residual tumor near the mitral anulus, but is clinically well 15 years postoperatively. A fifth unoperated patient died suddenly 8 years after presumptive diagnosis of fibroma at the age of 83 years. This experience suggests that patients who have undergone successful excision of cardiac fibroma have an excellent probability of remaining free of disease.

Child↗
PubMed1982

Porcine heterograft valve replacement in children.

From 1973 to 1980, 49 patients under 18 years of age survived cardiac valve replacement with Hancock porcine heterografts. Complete follow-up has been obtained on 44 patients (90%) in whom 46 valves were placed. There were 30 boys and 14 girls with an age range of 2 to 18 years (mean 10.0 years). Severe prosthetic valvular dysfunction requiring valve replacement occurred in eight valves in seven patients at 15 to 60 months postoperatively (mean 34.1 months), yielding a calculated replacement rate of 7.1% per patient-year. All eight valves demonstrated severe calcification with stenosis, two valves had significant insufficiency secondary to leaflet disruption, and one valve had a large leaflet perforation. Thirty-one patients with valves in place at 7 to 90 months (mean 38.4 months) are alive, but six have clinical evidence of progressive valvular dysfunction. The mean age at the time of the original Hancock valve placement of the group of patients having undergone replacement of a failed prosthesis together with those with clinical evidence of prosthetic dysfunction was 8.0 years, which is significantly less than that of the remaining group of patients with normally functioning valves (mean 11.2 years, p = 0.043). Actuarial curves demonstrate a predicted replacement-free rate of 87.4% +/- 5.9% at 3 years. 82.3% +/- 7.5% at 4 years, and 58.5% +/- 15.7% at 5 years. On the basis of these data and other reports of early failure in the literature, we have discontinued the routine use of Hancock porcine heterografts for cardiac valve replacement in children in favor of mechanical prostheses.

Actuarial Analysis↗
PubMed1981

Extrinsic obstruction of the Björk-Shiley valve in the mitral position.

Four recently seen patients with acute, extrinsic obstruction of a Björk-Shiley prosthesis in the mitral position are described. In 2 of them, the disc occluder was stuck in the closed position by a strand of chordal tissue, which was compressed between the disc edge and valve rim. In another patient, sticking of the disc by a similar mechanism was caused by a suture that migrated into the valve orifice. Intermittent malfunction of the valve in the fourth patient was related to interference with valve opening by ventricular myocardium and occurred when the patient lay on his right side. The mechanism of extrinsic obstruction of the Björk-Shiley valve and their recognition, treatment, and prevention are discussed.

Aged↗
PubMed1981

Intestinal injury associated with low-voltage electrocution.

A 16-month-old girl suffered low-voltage electrocution from a hairdryer while playing in the bathtub. At exploratory laparotomy about 18 hours postinjury because of distention and persistent, unexplained acidosis, a 1.5-cm diameter necrotic lesion in the terminal ileum surrounded by multiple superficial serosal burns and a 1.5 x 1.0 cm eschar in the mid-transverse colon were found. The lesion in the small intestine was resected with wide margins and the colon lesion exteriorized. The child ultimately expired 12 hours after surgery from recurrent cardiac arrest. Abdominal visceral injury associated with major electrical injury is reviewed. Although the colon is probably the most frequently injured, the esophagus, pancreas, gallbladder, and small intestine have also been reported as directly injured by electric current. The importance of meticulous examination of the abdominal contents at laparotomy is stressed. Lesions of the small intestine should be resected with wide margins when possible and lesions of the colon resected with a colostomy of the injured segment exteriorized.

Baths↗
PubMed1980

Measurement of deep muscle temperature in ischemic limbs.

Temperature profiles extending from the deep muscle out to the surface at points above and below the knee were measured using a 22 gauge thermistor probe in the form of a hypodermic needle in 15 ischemic limbs before amputation and 3 normal limbs before and elective surgery. Of the 15 ischemic limbs studied, 8 had below-knee and 7 above-knee amputations, all of which healed without requiring revision. The mean difference between the maximum deep muscle temperature measured 15 cm above and 10 cm below the knee was 1.01 degree C in the below-knee amputation group and 1.06 degree C in the normal group. The temperature difference in the below-knee and above-knee groups was statistically significant (p less than 0.027). This relatively simple and easily performed technique of measuring deep muscle temperature appears to be a useful adjunct in choosing the amputation level.

Aged↗
PubMed1980

Splenic arteriovenous fistula.

A patient with an uncalcified splenic artery aneurysm with an arteriovenous fistula and aneurysmal dilatation of the splenic vein who underwent splenectomy and resection of the fistula is described. Splenic arteriovenous fistulas are rare and are usually associated with aneurysms of the splenic artery. Patients with these fistulas frequently have signs and symptoms of portal hypertension and may often present with upper gastrointestinal hemorrhage. The patient described in this report was asymptomatic, and the only manifestation of the fistula was a loud, continuous bruit in the left flank noted on routine physical examination. Although an upper abdominal incision can be used to manage most splenic artery aneurysms, a left thoracoabdominal incision is advocated in the presence of an arteriovenous fistula, particularly in anticipation of portal hypertension or aneurysm of the splenic vein.

Arteriovenous Fistula↗
PubMed1979

A simple technic for predicting daily maintenance dose of warfarin.

Warfarin anticoagulation data from forty-seven patients studied retrospectively was used to develop an algorithm for predicting daily maintenance dose of warfarin. A plot of prothrombin time versus cumulative warfarin loading dose was made for each of the forty-seven patients and the aera under the curve (AREA) measured from the baseline prothrombin time to a prothrombin time of 20 seconds. A linear correlation between the established daily maintenance dose of warfarin and AREA was derived regression analysis: Daily maintenance dose (mg/day) = 0.0465 x (AREA) + 1.5. The correlation was then used to predict daily maintenance dose in twenty-four patients studied prospectively. The mean prothrombin time for a seven day stabilization period after loading for all patients in the prospective study was 21.5 +/- 2.2 seconds and the seven day mean prothrombin time for each patient fell between 19 and 24 seconds. The results of the prospective study indicate that this technic is useful in the early, accurate prediction of a daily maintenance dose of warfarin.

Adult↗