Vocal fold medialization by surgical augmentation versus arytenoid adduction in the in vivo canine model

There are a variety of methods for treating unilateral vocal cord paralysis, but to date there have been few studies that compare these phonosurgical techniques by using objective measures of voice improvement. Vocal efficiency is an objective voice measure that is defined as the ratio of the acoustic power produced by the larynx to the subglottic air power. Vocal efficiency has been found to decrease with glottic disorders such as vocal cord paralysis and carcinoma. This study compared the effects of vocal fold medialization by surgical augmentation to those of arytenoid adduction on the vocal efficiency, videostroboscopy, and acoustics (jitter, shimmer, and signal-to-noise ratio) of a simulated unilateral vocal cord paralysis in an in vivo canine model. Arytenoid adduction was superior to surgical augmentation in vocal efficiency, traveling wave motion, and acoustics.

A functional evaluation of ansa cervicalis nerve transfer for unilateral vocal cord paralysis: future directions for laryngeal reinnervation

There are a variety of methods for treating unilateral vocal cord paralysis, but to date there are few objective studies that evaluate the functional results of nerve transfer from the ansa cervicalis. Six dogs underwent unilateral recurrent laryngeal nerve section with immediate reanastamosis to the sternothyroid branch of the ansa cervicalis. After 5 to 6 months, measurements of vocal efficiency and acoustic parameters, videolaryngoscopy, videostroboscopy, and evoked electromyography were performed. Identical measurements were made in eight control dogs during normal electrically induced phonation and a simulated unilateral recurrent laryngeal nerve paralysis. Histologic analysis of both vocalis muscles, recurrent laryngeal nerves, ansa cervicalis, and the ansa-recurrent laryngeal nerve anastamosis site was performed. Evidence of reinnervation was found in all of the animals that underwent nerve transfer. The vocal efficiency and acoustic quality after ansa cervicalis nerve transfer were dependent on the degree of electrical stimulation from the transferred nerve to the reinnervated cord during phonation. In the absence of electrical stimulation to the nerve transfer, physiologic vocal cord motion could not be elicited from the reinnervated cord.

An in vivo canine model for testing treatment effects in laryngeal hyperadduction disorders

Adductor spastic dysphonia is a voice disorder characterized by a strained, squeezed, effortful voice produced by true and false cord hyperadduction. An in vivo canine model has been developed to simulate hyperadduction of the true cords. Using this model, the thyroarytenoid muscle was found to have a greater effect on intraglottic and subglottic pressure than cricothyroid muscle contraction. The intraglottic and subglottic pressure was reduced after simulated recurrent laryngeal paralysis. This model can be used in future studies to compare laryngeal treatment modalities for disorders that have a component of vocal cord hyperadduction, such as spastic dysphonia.

Surgical management of lung cancer with solitary cerebral metastasis

Between 1964 and 1986, 19 patients underwent resection of both a primary lung cancer and the associated brain metastasis. One patient underwent resection of 2 separate primary lung cancers and the associated metastases. The 12 men and 7 women ranged in age from 42 to 67 years (mean, 54.6 years). The cell type was adenocarcinoma in 12 tumors, squamous or adenosquamous cell in 5, large cell undifferentiated or anaplastic in 2, and malignant carcinoid in 1 tumor. The types of resection were as follows: lobectomy for 12 neoplasms, pneumonectomy for 5, bilobectomy for 2, and wedge resection for 1 neoplasm. Radiotherapy to the brain was given in connection with sixteen of the twenty craniotomies. The patient with 2 separate primary neoplasms survived 19 years before dying 5 months after the second craniotomy. The mean survival is 8.0 +/- 2.1 years (+/- the standard error), and the median survival is 1.67 years. Survival at 1 year was 65 +/- 10.7% and at 5 years, 45 +/- 11.1%. On univariate analysis, the following factors were found to correlate significantly with longer survival: a lung tumor in Stage I or II; negative mediastinal nodes; curative rather than palliative resection of the lung tumor; and age younger than 55 years. However, on multivariate analysis, only curative resection was a significant factor (p less than 0.01). We believe these results justify continued application of this combined surgical approach to patients having limited-stage lung cancer with a solitary brain metastasis.

Use of a zipper in cardiac surgical operations

A simplified technique to gain repeated access to the median sternotomy incision is presented. The technique involves the use of a sterile polyester zipper attached to the skin edge. The sternum remains open. Unzipping the zipper allows for repeated relief of cardiac tamponade and viewing of cardiac action. Other advantages include prevention of cardiac compression or kinking of assist device cannulas from sternal closure, ease in changing of dressings, and quick removal of ventricular assist devices without reopening the sternum.

Two-step purification of tryptophan-accepting tRNA from Bacillus stearothermophilus

Tryptophan-accepting tRNA has been purified essentially to homogeneity from Bacillus stearothermophilus. Crude tRNA was chromatographed first on benzoylated DEAE-cellulose and then on Sepharose 4B with reverse salt gradient elution. The product has tryptophan acceptor activity in excess of 2 nmol [14C]tryptophan per A260 unit. This procedure avoids costly aminoacylation, a step characteristic of other one- and two-step procedures. In two separate purifications 7 and 11 mg of tRNAtrp were prepared from 750 and 1000 g of frozen cells, respectively. This yield compares favorably with that from other procedures. The pure tRNAtrp has been crystallized under several different conditions.

Management of penetrating cardiac injuries: the role of emergency room thoracotomy

Sixty-four consecutive patients with penetrating cardiac injuries were treated between January, 1977, and January, 1983, at the University of Maryland Hospital. Twenty-eight patients had major associated injuries of other organs. The patients were divided into groups according to their clinical status on arrival. An aggressive approach was utilized including early emergency room (ER) thoracotomy for "lifeless" or deteriorating patients. Three patients required immediate cardiopulmonary bypass for repair of their injuries. Twenty-one (57%) of the 37 patients undergoing ER thoracotomy survived; most of the deaths occurred in patients arriving "lifeless" from gunshot wounds. Twenty-four (89%) of the 27 patients who were in stable enough condition to undergo initial repair in the operating room (OR) survived. Overall survival was 45 patients (70%). Though superficial wound infections developed in 18 patients, there were no deep or systemic infections. None of the survivors sustained severe neurological sequelae. Five patients underwent late reoperations for closure of a ventricular septal defect (2), mitral valve replacement (1), and pericardiectomy (2) with no deaths. Though repair of penetrating cardiac injuries should preferably be carried out in the OR, immediate thoracotomy for "lifeless" or deteriorating patients can be performed in the ER with a low incidence of direct surgical complications and with high patient survival.

Chloramphenicol kills Haemophilus influenzae more rapidly than does ampicillin or cefamandole

The bactericidal effects of chloramphenicol and three beta-lactams (ampicillin, cefamandole, and penicillin G) were measured for 27 strains of Haemophilus influenzae type b isolated from the blood or cerebrospinal fluid of infected infants. Of the ampicillin-susceptible strains, 75% were killed by less than 2.0 micrograms of each antibiotic per ml; however, the concentration of the beta-lactam agents required for bactericidal activity was higher than that required for inhibitory activity. Chloramphenicol was the only agent which had no marked discrepancy between inhibitory and bactericidal concentrations regardless of beta-lactamase production. Importantly, chloramphenicol was more rapidly bactericidal than either ampicillin or cefamandole. The bactericidal requirement of ampicillin was increased by the presence of chloramphenicol for about one-third of the isolates examined. Neither the inhibitory nor the bactericidal activity of chloramphenicol was influenced by ampicillin. Synergy occurred for only two beta-lactamase-positive isolates. The more rapid bactericidal action of chloramphenicol persisted even in the presence of ampicillin. The rapid bactericidal action of chloramphenicol with or without ampicillin supports the use of chloramphenicol alone or with ampicillin for H. influenzae infections.

Repair of DNA alkylation induced in L1210 leukemia and murine bone marrow by three chloroethylnitrosoureas

The removal of DNA adducts is an essential step of DNA repair following exposure to chloroethylnitrosoureas. Adduct removal was evaluated in both L1210 and murine bone marrow DNA for lesions induced by three chloroethylnitrosoureas. 1-(2-Chloroethyl)-3-cyclohexyl-1-nitrosourea, a marrow-toxic agent with high carbamoylating activity, was not removed in either system for at least 6 to 12 hr. These results were compared with those obtained with two glucose-linked chloroethylnitrosoureas, chlorozotocin and 1-(2-chloroethyl)-3-(beta-D-glucopyranosyl)-1-nitrosourea. Both of these agents have low marrow toxicity at therapeutic doses. Chlorozotocin, which has very low chemical carbamoylating activity, was found to permit approximately 40% removal of drug-derived DNA adducts in both systems within the first 6 hr and approximately 50% by 18 hr. The second glucose-linked analog, 1-(2-chloroethyl)-3-(beta-D-glucopyranosyl)-1-nitrosourea, has relatively high carbamoylating activity and was found to inhibit early removal of DNA adducts as effectively as does 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea. It would thus appear that the selective marrow-sparing property of the sugar-linked chloroethylnitrosoureas is not dependent upon carbamoylation-mediated differences in the rate and extent of DNA adduct removal. In view of the comparable therapeutic activity of the three drugs for L1210 leukemia, therapeutic efficacy does not appear to be impaired by the increased rate of adduct removal observed with chlorozotocin in this system.

Dipyridamole-aspirin as thromboembolic prophylaxis in patients with aortic valve prosthesis. Prospective study with the Model 2320 Starr-Edwards prosthesis

In a prospective study, the efficacy of a dipyridamole-aspirin regimen in prevention of thromboembolism was evaluated in 50 patients having isolated aortic valve replacement with the Model 2320 Starr-Edwards prosthesis. These operations were performed between February, 1972, and October, 1974. In 1,380 patient-months of follow-up, there was a 20% incidence of thromboembolism with a rate of 8.7/100 patient-years and a 19% probability of an embolic episode occurring by 3 years. Seven patients had transient episodes, two had permanent neurologic residua, and one patient died. Comparison is made to a similar group of patients having solitary aortic valve replacement but receiving no medication, studied by Starr and associates. There was no statistical difference in the incidence of thromboembolism between the two groups. In November, 1975, all patients were converted to a regimen of warfarin therapy. Since conversion to anticoagulation, there have been two thromboembolic episodes in 2,132 patient-months of follow-up for a rate of 1.1/100 patient-years. We conclude that the use of antiplatelet therapy in the form of dipyridamole-aspirin is inadequate for routine thromboembolic prophylaxis following SE 2320 aortic valve replacement.

Delayed pericardial disease after radiotherapy

Delayed chronic constrictive pericarditis developed in seven patients 51 to 268 (mean 116) months after radiotherapy. Six of the seven complained of exertional dyspnea that was initially believed to be caused by mediastinal fibrosis. All patients had raised jugular venous pressure, although in two patients this finding was not appreciated by the primary physician. There were no consistent noninvasively identifiable features to allow prediction of constrictive pericarditis other than consideration of its existence and careful examination of the cardiovascular system. All patients had constrictive pericarditis proved at cardiac catheterization. Of the five patients who underwent pericardiectomy, two had an excellent functional result, one has residual pericardial constriction and two died of unrelated causes. Recommendations for the treatment of radiation-induced pericardial disease are given.

Giant coronary pseudoaneurysm. Five-year follow-up after bypass grafting

A roentgenogram of the shoulder in a 25-year-old man with an athletic injury revealed a large mass along the left heart border. Evaluation with coronary arteriography established the diagnosis of a massive aneurysm of the left anterior descending coronary artery. The aneurysm was excised and a saphenous vein bypass graft was placed into the distal artery. Histologic examination revealed that the excised segment was a false aneurysm. Five years postoperatively, the patient is asymptomatic and the graft remains widely patent.

Value of anterior mediastinotomy in bronchogenic carcinoma of the left upper lobe

Neoplasms of the left upper lobe may spread directly to the anterior mediastinal group of nodes without involving the inferior tracheobronchial, superior tracheobronchial, or paratracheal nodal chain. Routine cervical mediastinoscopy does not sample the anterior mediastinal node group. Parasternal anterior mediastinotomy was performed in 28 patients with left upper lobe carcinoma and normal findings from cervical mediastinoscopy. Despite the normal findings at cervical mediastinoscopy, 10 of the 28 patients were deemed to have inoperable disease because of spread of the neoplasm to the anterior nodal group or because of direct neoplastic involvement of the aorta or main pulmonary artery. All patients in whom results of anterior mediastinotomy were normal had resectable lesions at thoracotomy. Fourteen of the 16 patients who came to thoracotomy had normal hilar nodes. Parasternal anterior mediastinotomy, introduced by Chamberlain, should be performed in addition to standard cervical mediastinoscopy if the nodal drainage of left upper lobe neoplasms is to be more completely evaluated. Combining these two procedures samples all major drainage pathways except the posterior mediastinal nodal chain.

Thoracic traction for median sternotomy dehiscence

Standard management of median sternotomy dehiscence sometimes fails to achieve lasting reduction and fixation of the sternal halves. An effective method of external thoracic traction that augments internal fixation of the sternal fracture is presented.