Right upper lobectomy twenty years after left pneumonectomy. Preoperative evaluation and follow-up.

Quantitative perfusion lung scanning coupled with spirometry and balloon occlusion of the pulmonary artery supplying the lung to be resected have been used to predict the potential operability of patients being considered for pneumonectomy. These techniques were adapted for the lobar level prior to performing a right upper lobectomy in a 59-year-old man who had undergone a left pneumonectomy 20 years previously. This case demonstrates how physiologic reserve can be predicted in patients who require sequential pulmonary resection.

DDD pacemakers maximize hemodynamic benefits and minimize complications for most patients.

A 44-month retrospective analysis was performed on 666 pacemakers implanted at Mt. Sinai Medical Center. Mapping techniques and endocardial waveform analyses were used during lead positioning to ensure the best electrical environment. The optimal pacing lead type was selected based on the clinical situation. Follow-up evaluations were rigorous. Patient population ranged in age from 28 to 103 with a mean of 78 years at time of implant. Seventy percent of the patients received DDD pacemakers with an 81% survival incidence at 44 months. Of the VVI population (30% of the implants), there was a 62% survival incidence. Most problems associated with the pacing systems were related to the atrial channel. Loss of atrial sensing occurred in 7.5% of the population and was corrected noninvasively in 5.8%. Due to chronic loss of atrial sensing, 1.7% of the population remained programmed to DVI/VVI. A total of 7.7% were chronically reprogrammed from DDD to VVI, 5.6% secondary to atrial fibrillation. Reoperations were necessary in 1.2% of the malfunctioning systems that could not be corrected by reprogramming. The following conclusions were reached: (1) maximizing hemodynamic benefits and minimizing pacemaker complications permitted a survival rate equal to or better than that of the general population, and (2) chronic problems related to the atrial lead and malfunctions of the pacing system were minimized by careful patient selection, appropriate pacemaker and lead selection, endocardial waveform analysis, and thorough follow-up.

The laser: an alternative for palliative treatment of obstructing intraluminal lesions.

Twenty nine patients with carcinoma obstructing the colon, six obstructing the gastroesophageal junction, six obstructing the tracheobronchial tree, and one patient with recurrent transitional cell cancer of the bladder invading the rectum, not amenable to surgical resection, were treated by laser photocoagulation. Forty were treated with the Nd:YAG laser and two with the CO2 laser. There were 26 men and 16 women with an average age of 73.8 years. The locations of the tumors were 17 rectal, six rectosigmoid, one transverse colon, two descending colon, four ascending colon, six gastroesophageal, and six in the tracheobronchial tree. Symptoms consisted of obstruction and/or bleeding. Seventeen patients were poor surgical candidates, 25 were unresectable due to widespread disease, two had recurrence at the anastomosis, and three patients had another primary site not controlled by their previous surgical procedure. There were seven complications--three perforations, a rectovaginal fistula, two failures in therapy, and lower GI bleeding. Nineteen patients have died of their disease. Tumors were eradicated in two patients. Forty patients had remained free of referring symptoms of obstruction and bleeding.

Pacemaker clinic evaluations: key to early identification of surgical problems.

The pacemaker center evaluation was responsible for the timely reoperation of 341 pacemaker patients over the last three years. The most common indication for reoperation was battery end-of-service (46.3%). Battery testing and maintenance of accurate records for trend analysis ensures prompt generator replacement. Atrial and/or ventricular lead malfunction was the second largest indication (26.3%). Lead malfunction detected by bracketing capture and sensing thresholds included: dislodgement, penetration, exit block, fracture, insulation failure, and abnormal sensing. The third largest indication for reoperation was pacemaker pocket erosion and/or infection (15.5%). Examination of the pacemaker pocket site is an integral part of an evaluation. In conclusion, the three largest indications for reoperations can be best demonstrated in a pacemaker center where evaluations are personal and thorough, and accurate record keeping is maintained.

Technique for the surgical extraction of permanent pacing leads and electrodes.

When a pacing lead becomes infected, the most expedient and successful therapy is its removal. A new surgical extraction technique, combining the use of fluoroscopy and a limited surgical dissection of the right atrium, is presented for the removal of a lead entrapped in the heart or venous system.

Implant experience with unipolar polyurethane pacing leads.

A total of 905 unipolar polyurethane pacing leads have been implanted by the first author's group, between April 1978 and February 1982, with a mean implant of 1.4 years. Twelve leads were explanted and analyzed. Eleven of the explanted leads exhibited some degree of surface damage or "frosting." Of the 11, five atrial (Medtronic 6991 U) and one ventricular (Medtronic 6971) lead suffered complete insulation failure. One lead was completely free from surface damage. Clinically, insulation failure presented as muscle stimulation and/or battery depletion. Surface damage appears to be due to an environmental stress cracking (ESC) mechanism. ESC requires both a surface active agent from the hostile biological environment, and stress in excess of a threshold value. The minor surface damage or "frosting" of the eleven explanted leads was typically 10 to 15 microns deep on leads implanted about one year, although one device (15 months) had 30 micron cracks. No lead failures in this series were attributed to this shallow cracking mechanism. The severe cracking of the six Medtronic leads leading to insulin failure was thought to be due to the unusually high tensile stresses imposed by manufacturing processes and ligatures. The incidence of failure was 7% (5/74) for the Medtronic 6991 U and 0.2% (1/454) for the Medtronic 6971. Medtronic lead manufacturing processes have been modified to reduce the high residual tensile stresses and a fixation sleeve has been added to reduce ligature stress.

Papillary muscle rupture following nonpenetrating chest trauma: report of a case with hemodynamic and serial echocardiographic findings and successful surgical treatment.

The pre- and postoperative echocardiographic features of a patient with severe mitral incompetence due to rupture of a papillary muscle following nonpenetrating chest trauma are presented. The mitral valve echocardiogram showed chaotic diastolic flutter suggestive of a ruptured papillary muscle or ruptured chordae tendineae. The preoperative ultrasound recording of the left ventricle revealed left ventricular enlargement and excessive motion of the interventricular septum. The echocardiogram taken 7 weeks after mitral valve replacement showed considerable regression of the left ventricular enlargement.

Mitral valve replacement in medically unresponsive congestive heart failure due to papillary muscle dysfunction.

Forty patients with a mean age of 65 years (range 44-76 years) were operated on; 30 of 40 patients (75%) had prior myocardial infarction. All had severe therapy-resistant congestive heart failure, 75% (30 of 40 patients) were symptomatic at rest, and 25% (10 of 40 patients) were symptomatic on minimal exertion. Cardiac index ranged from 1.24-2.84 L/min/m2 (mean 1.99). Left ventricular end-diastolic pressure ranged from 3-36 mm Hg (mean 18). All patients had significant mitral insufficiency and contractility was reduced markedly to moderately in 63% (25 of 40 patients). Significant coronary artery disease (obstruction greater than or equal to 75%) was present in all patients. All had mitral valve replacement, 30 had bypass surgery, and 7 left ventricular aneurysmectomy. Five died during surgery or before discharge (early mortality 12.5%). After a mean follow-up period of 16 months, another eight patients died, two with causes not related to the cardiovascular system (total mortality 32.5%). Of 20 patients with a cardiac index greater than or equal to 1.5 L/min/m2 and an ejection fraction greater than or equal to 0.40, 17 survived surgery and improved postoperatively. Mitral valve replacement for this group of patients is recommended.

Coronary artery bypass surgery in patients seventy years of age and older.

Fifty patients 70 years of age and older underwent coronary artery bypass surgery for disabling angina pectoris or congestive heart failure or both (two quadruple, 11 triple, 25 double grafts, 12 single). Twenty additional procedures were done (11 mitral valve replacements for papillary muscle dysfunction, six ventricular aneurysmectomies, four aortic valve replacements, and one repair of ventricular septal defect). Surgical mortality rate was 8 per cent (four patients). Total mortality rate was 14 per cent, after a mean follow-up of 17 months. Of 30 patients undergoing coronary artery bypass surgery alone, two died during surgery and none of follow-up. Age alone should not be a contraindication for coronary artery bypass surgery. Surgical risk is acceptable in older patients, and improvement can be expected in the majority of patients.

Noninvasive cardiac evaluation (NICE) of intracardiac shunts using inhaled radioactive carbon dioxide.

A totally new, noninvasive technique is presented for the detection and analysis of left-to-right cardiac shunts. Five millicuries of oxygen 15-labeled carbon dioxide is administered by a single-breath inhalation technique. The resultant lung washout curve accurately reflects the presence or absence of a shunt. The quantitative studies are promising, but the method must be compared with standard techniques in a statistically significant series. This work is in progress.

Long-term results of "simple" thrombectomy for thrombosed Björk-Shiley aortic valve prostheses.

During the past two years 8 patients were seen with thrombosis of their Bjork-Shiley aortic valves. Six patients were from our series, an incidence of 4% and 2 patients had their original valve implanted at another institution. All patients had substantial problems with anticoagulation therapy. Three died prior to operation. Early detection and emergency surgical intervention is mandatory for survival. At operation debridement of all thrombotic material from the valve provided satisfactory immediate hemodynamic improvements as well as freedom from complications for up to two years. Therapeutic levels of anticoagulation with warfarin are the only apparent protection from thrombosis of the Bjork-Shiley aortic valve.