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Biomedical subjects

W C Alford

Publications and source records attributed to W C Alford.

At least 19 recordsLinked to original sources

Videothoracoscopy: improved technique and expanded indications.

Current videoendoscopic technology and percutaneous techniques of exposure and dissection have been successfully applied to abdominal surgery with favorable results. Application of this technology to our practice of thoracoscopy is the basis of this report. Videothoracoscopy has been performed in 39 patients for the following indications: chronic pleural effusion, interstitial lung disease, mediastinal lymphadenopathy in lung cancer, persistent air leak after decortication, mediastinal mass, recurrent spontaneous pneumothorax, hydropneumothorax with persistent air leak, and pleural-based mass. The technique we employ includes lateral decubitus positioning and double-lumen endotracheal intubation with ipsilateral lung collapse. The videoscope, retractors, and instruments are introduced through separate 10-mm incisions. Percutaneous manipulation of instruments and the videoscope is guided by images produced on television screens without dissection, and if resection is performed, the incision is enlarged to allow specimen retrieval. Procedures performed using this technique include pleural biopsy, partial pleurectomy, lysis of adhesions, lung biopsies, staging lymph node biopsy, lung nodule biopsy, pleural-based mass resection, and mediastinal mass biopsy and resection. This videoendoscopic technique greatly improves visualization of thoracic anatomy, facilitating thoracoscopy and enhancing exploration of the chest. It is preferred over conventional thoracoscopy and, in some patients, reduces the magnitude of operation by avoiding thoracotomy.

Adult

Prophylaxis of atrial fibrillation with magnesium sulfate after coronary artery bypass grafting.

Ninety-nine consecutive consenting patients were prospectively entered into a randomized, double-blind, placebo-controlled trial to determine the efficacy of postoperative magnesium therapy on the incidence of cardiac arrhythmias after elective coronary artery bypass grafting. No patient had documented or suspected arrhythmias preoperatively. Forty-nine patients received 178 mEq of magnesium given over the first 4 postoperative days, and 50 patients received only placebo. The clinical characteristics of both groups were similar. The preoperative mean serum magnesium concentration was similar in both study (1.90 mEq/L) and placebo (1.90 mEq/L) groups. The mean postoperative serum magnesium concentration in study patients was significantly elevated over postoperative days 1 through 4 when compared with preoperative levels (p less than 0.001). The postoperative mean serum magnesium concentration in control patients declined and remained significantly depressed through postoperative day 3 (p less than 0.001), but increased to preoperative levels by postoperative day 4. The mean serum magnesium concentration was significantly greater in the study patients as compared with the control patients over postoperative days 1 through 4 (p less than 0.001). Although there was no significant difference between groups with respect to episodes of ventricular arrhythmias, there was a significant decrease in the number of episodes of atrial fibrillation in the group receiving magnesium therapy (p less than 0.02). There were no recognized adverse effects of magnesium therapy. Prophylactic magnesium administration seems to lessen the incidence and severity of atrial fibrillation after coronary artery bypass grafting.

Adult

Internal mammary artery graft at reoperation: risks, benefits, and methods of preservation.

To determine the effect of a prior internal mammary artery (IMA) graft on coronary artery bypass reoperation (CABR), we reviewed our experience with 410 consecutive patients: 313 received only saphenous vein grafts at initial coronary artery bypass grafting (CABG), and 97 received at least one IMA graft at CABG. Cardiac catheterization data before CABG were available in 110 patients (56 received only saphenous vein grafts, 54 received at least one IMA graft), allowing comparison of left ventricular function at CABG and CABR. Injury of the IMA graft occurred in 5 patients (1 death), but presence of an IMA graft was not an independent predictor of morbidity or mortality. Overall, the incidences of complications and deaths were higher in patients with saphenous vein grafts than in patients with IMA grafts, though not significantly so. Internal mammary artery grafts better preserved cardiac function: patients with IMA grafts had worse left ventricular function before CABG but better left ventricular function before CABR than patients with saphenous vein grafts. Left ventricular function deterioration from before CABG to before CABR was significantly less in patients with IMA grafts. We conclude that the risk of CABR is not increased by a previously constructed IMA graft and that left ventricular function is better preserved at CABR when an IMA graft was constructed at the initial operation.

Confounding Factors, Epidemiologic

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History, 20th Century

Efficacy of cefazolin, cefamandole, and gentamicin as prophylactic agents in cardiac surgery. Results of a prospective, randomized, double-blind trial in 1030 patients.

In an effort to develop an improved regimen of antibiotic prophylaxis in cardiac surgery, 1030 patients who were to have elective cardiothoracic surgery involving a median sternotomy were selected at random to receive cefamandole or cefazolin, with or without gentamicin, in a prospective double-blind study. Cefazolin was significantly less effective than cefamandole at both the sternal (1.8% vs. 0.4%, respectively, p less than 0.05) and donor sites (1.3% vs. 0%, respectively, p less than 0.02). Seven Staphylococcus aureus infections occurred among cefazolin recipients as compared with no such infections among the patients receiving cefamandole (p less than 0.01). All five wound infections yielding fungi or gentamicin-resistant gram-negative rods occurred in patients who had received gentamicin as a second prophylactic agent. These data suggest that gentamicin has no role as a prophylactic antibiotic in cardiac surgery and that, compared with cefamandole, cefazolin offers unreliable prophylaxis against deep infection at both the sternal and donor sites.

Cardiac Surgical Procedures

Internal mammary artery grafts: technical factors influencing patency.

Eight hundred fourteen patients with internal mammary artery (IMA) coronary artery bypass grafts have been restudied 961 times with coronary arteriography, primarily to evaluate the patency of the grafts in the setting of symptomatic coronary occlusive disease. Their records were reviewed to assess graft patency as related to the technical aspects of coronary artery bypass surgery. Patency was evaluated using life-table analysis of the data. The method of harvesting the IMA played no role in patency. The left anterior descending coronary artery was the recipient coronary artery with the highest patency rate. The left IMA had a significantly higher patency rate than the right IMA. As a group, the IMAs had a significantly higher patency rate than saphenous vein grafts. However, there was no difference between right IMA grafts and saphenous vein grafts. The mammary artery grafts that remained patent throughout the study had a significantly higher blood flow after bypass than did those that became occluded (43.0 +/- 0.9 versus 28.9 +/- 1.8 ml/min; p less than .001).

Blood Flow Velocity

The cost of coronary bypass procedures.

We reviewed the financial records of 200 succesive patients who had coronary artery bypass surgery in the first three months of 1976. The average hospital bill was $7,690 and the average length of stay was 18 days. The highest bill was $28,329 (79 days) and the lowest was $6,126 (11 days). The average total physician charge to the patient was $3,240. The total average hospital and physician cost was $10,930.

Coronary Artery Bypass

Median sternotomy dehiscence.

Sternal dehiscence requiring reoperation occurred in 36 out of 4,531 patients who had a sternotomy incison within an eight-year period. Twisted sternal wire sutures were used for the first four years and a crimped steel plate fixation was used during the second four years with a marked and significant decrease in the incidence of dehiscence from 17 out of 1,000 patients to 3 out of 1,000 patients. Thirty-five of the 36 patients were men, and 4 required reoperation for bleeding. Other factors such as mammary artery dissection, tracheostomy, and body weight of more than 82 kg were not significant. Although infection was noted in 20 patients, it was thought to be secondary. Early reoperation with antibiotic irrigation achieved wound stability in the 34 survivors with only 3 patients requiring additional procedures for chronic osteomyelitis of the sternum.

Anti-Bacterial Agents

The effectiveness of surgical treatment of acute aortic dissection.

Ten consecutive patients have undergone operative repair of acute aortic dissection at St. Thomas Hospital in the last three years. Two died. To assess the status of the residual aorta, all 8 survivors were evaluated by postoperative aortography. Only the patient with a clotted dissection on preoperative study showed no residual dissection of the distal aorta. Analysis of postoperative aortograms suggests that the original dissection reentry points become sites of inflow following removal of the original intimal tear. No death resulted from these residual abnormalities. Retrograde dissection and aortic insufficiency were obliterated. The major sites of aortic rupture were removed. It is concluded that surgical therapy for acute aortic dissection is effective in that it avoids the major sources of mortality. The resultant surviving population must be carefully observed in view of the high frequency of residual aortic abnormality.

Aortic Dissection

Further evaluation of the surgical treatment of obstructive disease of the left main coronary artery.

A protocol for the operative management of two patient groups with left main coronary artery disease has been evaluated. The period prior to and during induction of anesthesia is managed without using aortic balloon counterpulsation. Of the 86 patients undergoing coronary artery bypass for left main coronary artery disease from 1970 to 1973, there was a surgical mortality of 8.1%. Follow-up of the survivors from 48 to 87 months revealed three coronary and five non-coronary related deaths with survival to seven years of 75.6 +/- 5%. If the operative mortality is excluded, there is an observed survival to seven years of 82.4 +/- 4.8%, almost the same as a "normal" population of similar age and sex. Utilizing the same protocol, 90 similar patients undergoing coronary artery bypass in 1976 had an operative mortality of 4.4%. The deaths were not related to induction of anesthesia. The perioperative infarction rate (2%) and postoperative cardiac enzyme determinations were no greater in a random group having the same operation for less severe forms of coronary artery disease during the same time period. This method of management for patients with significant left main coronary artery disease is judged superior to other more complex techniques.

Coronary Artery Bypass

Techniques and results of ventricular aneurysmectomy with emphasis on anteroseptal repair.

We have reviewed an 8 year experience with ventricular aneurysmectomy in 170 patients. Ninety percent had anterior aneurysms and underwent "anteroseptal repair" with exclusion of nonfunctioning septal myocardium. Preoperative left ventriculograms and coronary arteriograms were studied and "scored," and the hospital mortality and long-term survival rates for various subsets of the group were correlated with their radiographic data. A postoperative score for the coronary arteries was developed according to the preoperative anatomy and the vessels bypassed. Both the ventriculogram score and the postoperative coronary score had significant effects on both hospital mortality and long-term survival rates. The severity of preoperative coronary disease had minimal predictive value. Recent myocardial infarction did not preclude a good result. The value of an aggressive surgical approach to patients with ventricular aneurysm was confirmed even for certain subsets with indicators suggestive of poor prognosis. Anteroseptal repair appears to give optimal results for the typical "anterior" aneurysm. All suitable coronary arteries should be bypassed. Attention to the details of preoperative anatomy and function allows the most accurate prediction of prognosis and dictates the optimal therapeutic approach.

Adult

The natural history of long-term cardiac pacing.

During the past ten years, 504 patients have received one or more pacemakers for complete heart block or other arrhythmia. Of these patients, 306 (61%) are alive. Actuarial analysis shows a steady attrition of 9.4% per year for the first five years, decreasing to 7% per year for the second five years. The overall survival was decreased for patients with congestive heart failure and advanced age and was not affected by the history of Stokes-Adams attacks, initial pulse rate below 50 per minute, or a QRS duration greater than 0.12 second prior to pacing. Cardiac problems were the primary cause of death in 71% of the patients. The natural history of patients with permanent pacemakers depends, more than any other factor, on the function of the left ventricle.

Adult

Ischemic cardiomyopathy: medical versus surgical treatment.

The natural history of patients with ischemic heart disease and depressed left ventricular function is dismal, and medical therapy has failed to alter its course. To assess the results of aorta-coronary bypass grafting in patients with coronary artery disease and decreased left ventricular ejection fraction (LVEF less than or equal to 0.3), we compared 70 medically treated patients to 46 patients having aorta-coronary bypass grafting. The duration of follow-up was 6 to 72 months (mean 19 months). All patients had angina pectoris. Congestive heart failure was present in 56 percent (39/70) of the medical and 43 percent (20/46) of the surgical group. The medical group had a mean LVEF of 0.20 and a mean left ventricular end-diastolic pressure (LVEDP) of 29 mm. Hg. The surgical group had a mean LVEF of 0.21 and a mean LVEDP of 24 mm. Hg. Three vessel disease was found in 60 percent (42/70) of the medical group and 83 percent (38/46) of the surgical group. The operative mortality rate in the surgical group was 4 percent (2/46). There were four late deaths. The 2 year actuarial survival rate for medical and surgical groups was 47 percent and 83 percent, respectively. Significant improvement in angina pectoris and/or congestive heart failure was found in 16 percent (11/70) of medically treated patients and 95 percent (38/40) of the surgically treated patients. Aorta-coronary bypass grafting can be performed in patients with poor left ventricular function with a low operative mortality rate, relief of angina pectoris, and improvement in symptoms of congestive heart failure.

Adult

Results of reoperation for failed aortocoronary bypass grafts.

Thirty-one patients underwent reoperation for failure of one or more previous aortocoronary bypass grafts. Thirty-nine grafts were replaced. Twenty-four grafts were constructed to vessels not thought to be significantly diseased at initial operation. There were no early or late deaths. Postoperative morbidity was comparable to initial prodecures. Of 24 patients followed up for more than six months., 62% clearly experienced improvement without evidence of perioperative or postoperative infarction. Reoperation for failed aortocoronary bypass grafts can be achieved without excess risk, but with long-term results less optimistic than initial procedures.

Arm

Cost of cardiac pacing.

The patient with a permanent pacemaker faces significant lifetime medical expenses. The financial records of 15 patients with more than 4 years' (average 73 months) of cardiac pacing were reviewed to establish the basic cost of pacing. Each pacemaker was electively replaced after 24 months of service. During the total of 1,096 months of pacing there were 65 hospital admissions. Medical expenses for the 15 patients totaled $112,160, of whic- $93,410 was for hospital expenses and $18,750 for physicians'fees. The average monthly cost per patient was $102 (range $84 to $130).

Aged

Unexpected death following aortocoronary bypass.

Since 1968, 1,800 aortocoronary bypass procedures have been performed with 37 operative or early postoperative deaths (2.1%). Twenty-one deaths (57%) occurred in patients with one or more of the following predetermined risk factors: ventricular aneurysm, decreased left ventricular contractility, left main coronary artery stenosis, valve replacement, recent infarction, or cardiogenic shock. The remaining 16 deaths (43%) were unexpected and occurred in patients with none of these risk factors.

Adult