Prosthetic reconstruction of the trachea and carina.

Twenty-six patients with tracheal stenosis owing to benign stricture and malignancy have had airway reconstruction with a molded silicone rubber prosthesis. In 8 patients the distal trachea and carina were replaced with a bifurcated graft. One individual with respiratory insufficiency could not be weaned from the respirator and died in 3 weeks. Two other patients with malignancy died 15 and 18 months following operation from disseminated cancer. The remainder are living from 1 to 5 years postoperatively. Eighteen individuals have had the trachea reconstructed with a straight graft of silicone rubber. In 5 patients with long strictures the prosthesis was invaginated into the upper and lower ends of the trachea. Thirteen individuals had circumferential resection of the airway with end-to-end anastomosis of the graft to the trachea. There was one early death from erosion of the innominate artery and 5 late deaths unrelated to the prosthesis.

Homograft replacement of the trachea using immunosuppression.

The experiments were divided into three-ring and five-ring autografts and allografts. In the animals receiving allografts, the trachea was exchanged between paired animals which were preoperatively immunosuppressed with Imuran (azathioprine) and postoperatively given Decadron (dexamethasone). Seven of the 14 dogs receiving a three-ring allograft survived until put to death months after the operation. Postmortem examination demonstrated a patent airway, but the cartilaginous rings were absent and the proximal and distal suture lines were approximated. By contrast, none of the dogs receiving the five-ring allografts survived beyond 29 days. In all, the cartilage had disappeared and the intervening fibrous tissue had collapsed and constricted the airway. On the other hand, in animals in which the trachea was simply transected and resutured over an area of seven to ten rings, leaving membranous portion intact, the trachea was entirely normal when the animals were put to death. It is concluded that tracheal replacement with an allograft is not feasible, even with immunosuppression. It is the blood supply to the grafted segment which precludes success.

Discriminate use of electrocautery on the median sternotomy incision. A 0.16% wound infection rate.

Between June 1978 and June 1989, superficial or deep mediastinitis (or both) developed in only five (0.16%) of 3118 consecutive patients. All patients studied underwent cardiac procedures through a median sternotomy and survived more than 7 postoperative days. The surgical team disciplined itself to divide presternal soft tissues with a scalpel and used electrocautery for pinpoint hemostasis only. This 0.16% infection rate was statistically significantly lower than those in 28 previously published studies (Pearson's chi 2 test, p less than 0.05). Twenty-four predisposing factors were evaluated by Fisher's exact test. Among these only an operating time longer than 3 hours is related to sternotomy infections (p = 0.0208), and this effect was not a strong one. Statistical evidence strongly suggests that discriminate use of electrocautery is a major reason for the lowest median sternotomy infection rate reported to date.

Postoperative mediastinitis: a comparison of two electrocautery techniques on presternal soft tissues.

Postoperative mediastinitis remains a serious surgical problem, complicating 0.4% to 5% of all cases. In an experiment designed to address this problem, 36 mongrel dogs underwent a median sternotomy incision. In group I (n = 18) all layers to the sternum were opened by a scalpel, and electrocautery was used only for pinpoint hemostasis. In group II (n = 18) the skin was opened by a scalpel and the remaining layers to the sternum were opened by electrocautery. Total kilojoules of electrical energy delivered to the tissues was 9.4 +/- 5.7 for group I and 44.1 +/- 7.0 for group II (p less than 0.001). Each group was randomly divided into three subgroups (n = 6): Ia and IIa were noninoculated controls; Ib and IIb were inoculated just before skin closure; Ic and IIc were inoculated and given one preoperative dose of cefonicid. The inoculum contained Staphylococcus intermedius in a 0.5 ml suspension of 10(8) organisms. Each animal was observed and the wounds were scored daily until death or until all survivors were put to death on the eighth postoperative day. Pleural fluid was cultured at autopsy. Ten dogs died of mediastinitis (four in IIa and six in IIb), but none from group I (p less than 0.01). Positive cultures from pleural fluid in matching subgroups (n = 6) occurred as follows: one in Ia and five in IIa (p less than 0.05); one in Ib and six in IIb (p less than 0.01); zero in Ic and two in IIc. We conclude that pinpoint hemostasis on the soft tissues of the sternotomy incision significantly reduces the severity and frequency of penetrating mediastinitis.

Mitral valve fibroelastoma.

Papillary fibroelastomas are rare benign tumors of the heart with predisposition for cardiac valvular involvement that were traditionally incidental findings at autopsy. Echocardiography now is allowing clinicians to diagnose these tumors in living patients. We reviewed the literature and, to our knowledge, are reporting the fifth documented case of a mitral valve papillary fibroelastoma in a living patient. Our patient was seen with bilateral transient ischemic attacks and was found to have a mitral valve tumor by two-dimensional echocardiography and cardiac catheterization. The tumor involved the entire mitral valve and subvalvular structures. The patient's valve was replaced with a bioprosthesis, and she remains free from symptoms.

Coronary-coronary bypass using internal mammary artery.

A free right internal mammary artery was used to bypass the right coronary artery in a patient with no available saphenous vein. The proximal end of the right internal mammary artery was anastomosed to the proximal right coronary artery, and the distal end of the free graft was anastomosed to the posterior descending coronary artery. Coronary-coronary bypass using a free internal mammary artery is an attractive approach to bypassing very distal vessels when other conventional grafting techniques are not possible.

Angiocatheter coronary artery reperfusion before cardioplegia for evolving myocardial infarction.

A simple reperfusion method using an angiocatheter during total cardiopulmonary bypass before aortic cross-clamping is described. This method has been used successfully for catastrophic evolving myocardial infarctions.

Carotid and aortic arch endarterectomy using hypothermic arrest with coronary bypass.

A 67-year-old man with symptomatic bilateral carotid artery obstructions and a large, friable atheromatous plaque of the transverse aortic arch required coronary artery bypass grafting for severe triple-vessel disease. An endarterectomy of the transverse arch and a left carotid endarterectomy were performed using deep hypothermic circulatory arrest concomitant with quadruple coronary artery bypass grafting. Recovery was uneventful. Hypothermic circulatory arrest provides adequate protection for this combined procedure and may eliminate cerebral embolization.

Surgical closure of the patent ductus arteriosus in the neonatal intensive care unit.

Efficacy of surgical closure versus indomethacin for treatment of patent ductus arteriosus in symptomatic neonates is an ongoing controversy. In recent years, surgical closure has been performed in the neonatal intensive care unit rather than the operating room in some centers, creating further controversy. In a retrospective study of the charts of 115 sequential patent ductus arteriosus surgical closures performed in the neonatal intensive care unit in premature infants, we found no surgical morbidity or mortality. Ninety-nine of these infants of less than 33 weeks gestational age were evaluated for various factors that might influence outcome. All were operated on within 72 hours of diagnosis, with an extra-pleural approach and metal clips used for closure of the ductus. All infants were extubated at an average of 33 weeks in each age group studied unless they had underlying severe bronchopulmonary dysplasia. We conclude that surgical closure of the symptomatic patent ductus arteriosus in neonates is safe and 100% effective, with none of the reported complications of indomethacin therapy, and should be the treatment of choice in neonates aged less than 33 weeks (gestational age) at birth with symptomatic patent ductus arteriosus. Closure performed in the neonatal intensive care unit eliminates transport risks and is ultimately safer and easier than transport to an operating room.

Enhanced ventricular recovery from high dose glucose, insulin and potassium with cardiopulmonary bypass support prior to cardioplegic arrest.

The concept that a beneficial preconditioning effect in ventricular recovery exists using high dose glucose (0.5 mg/kg), insulin (0.3 unit/kg), and potassium (0.2 mmol/kg) (GIK) with 20 min of normothermic cardiopulmonary bypass support (CPB) prior to 60 min of cardioplegic arrest (CA) was tested using 32 mongrel dogs divided into four subset test groups. Group 1 was given GIK and 20 min of CPB prior to CA, Group 2 was given GIK systemically over 10 min but no CPB prior to CA, Group 3 underwent 20 min of CPB without GIK and Group 4 was the control group with no GIK and no CPB assist. To focus specifically on in vivo ventricular recovery, dP/dT (mmHg/sec), developed pressure (dP) (mmHg), and segmental shortening (SS) (%) were measured prior to CPB, then 15, 30, 60, and 90 min after weaning from CPB, while left atrial pressure was kept constant. The average dP/dT (% recovery) at 60 min in Group 1 was 1,454 (122%) and significantly higher (P < or = 0.05) than Groups 2: 1,189 (99%), 3: 1,027 (79%) and 4: 1,030 (82%). Developed pressure at 90 min (% recovery) in Group 1, 88 (111%) was also better than Groups 3, 74 (86%), and 4, 72 (87%) (P < or = 0.05). Segmental shortening (% recovery) at 30 min was better in Group 1 (94%) than in Groups 2 (59%), 3 (73%) and 4 (68%). We conclude that GIK added to 20 min of CPB support prior to cardioplegic arrest enhances post CPB ventricular recovery and weaning from CPB.

Metastatic right atrial tumor in colon cancer with superior vena cava syndrome and tricuspid obstruction.

Metastatic colon carcinoma of the heart is a rare diagnosis, and an uncommon finding at autopsy. This report describes a patient with a huge intracavitary colonic metastasis of the right atrium causing both a superior vena cava syndrome and an obstruction of the tricuspid valve. To our knowledge, no similar case has been previously reported.

Clinical alternative bypass conduits and methods for surgical coronary revascularization.

Poor quality or inadequate length of venous and mammary conduits, or both, a severely calcified or atherosclerotic aorta, or diffuse coronary atherosclerosis are situations cardiovascular surgeons will be facing with increasing frequency. These conditions are more common to the increasing number of patients requiring reoperation for advancing disease and to the growing number of older patients requiring operation. Decisions will be made preoperatively or intraoperatively about the technique to be used. Extensive use of the internal mammary arterial graft, such as bilateral internal mammary artery bypass, sequential use of the mammary artery and use of a free internal mammary artery graft, are excellent choices. These methods can overcome some of the difficult situations of the severely calcified atherosclerotic aorta or the absence of adequate venous conduits. Coronary arterial bypass using the inverted internal mammary conduit has too low a flow to be considered. Composite conduits will help gain the length needed to solve both the inadequate length problem and the severely diseased aorta. Little clinical experience is reported to date. These methods should only be used when nothing else is available. The innominate to coronary arterial bypass and the left subclavian to coronary arterial bypass can help solve the problem of the severely atherosclerotic aorta. The coronary to coronary arterial bypass has been used to solve both the severely diseased aorta and the short conduit situation. These methods, while ingenious, are supported only by occasional isolated clinical experiences. A large number of researchers have done extensive work on the selective retrograde coronary venous bypass grafting, but the last published article of any clinical importance dates back to 1979 and this suggests that other alternatives may be better. This technique should be used as a last resort. The surgical arteriovenous fistula has been clinically applied during the coronary artery bypass procedure. The nonconduit revascularization technique of coronary artery endarterectomy is needed in the armamentarium of the surgeon. This technique is not ideal but presently has better results than intraoperative transluminal coronary angioplasty and far better results than laser angioplasty. These methods may be useful to solve the diffuse coronary arterial problem, but sequential grafting techniques should be considered first.

Surgical treatment of pulmonary aspergilloma.

Fourteen patients with aspergilloma (fungus ball) were reviewed. Hemoptysis was the major symptom (93%). Chest roentgenograms disclosed a "fungus ball" in every patient, and the mycelia of Aspergillus fumigatus were recovered from all resected specimens. One of three patients treated by pneumonectomy died post-operatively. A lobectomy was performed in ten patients, and segmental resection in one without mortality or significant morbidity. There has been no evidence of recurrence in a follow up of six months to ten years. On the basis of this experience and a review of the literature, excision of a solitary "fungus ball" is recommended when the diagnosis is made. Non-surgical therapy should be reserved for patients whose general medical status or pulmonary reserved prohibit resection.

Flow study of coronary-coronary bypass grafting.

Coronary-coronary bypass grafting was recently introduced for patients with either calcification of the ascending aorta or an inadequate length of graft. Flow in the coronary-coronary bypass graft and that in aortocoronary bypass to the same coronary bed was compared in eight mongrel dogs. Flow reserve of the proximal right coronary artery as a donor vessel to the coronary-coronary bypass graft was also measured. Both a coronary-coronary and aortocoronary bypass were constructed to the proximally ligated left anterior descending artery. The flow in each graft was measured with the other graft temporarily occluded. Flow reserve of the right coronary artery (mean internal diameter 1.5mm) proximal to the anastomosis was measured before and after opening of the coronary-coronary bypass. Mean(s.d.) flow as 50.0(12.3) ml/min in the coronary-coronary bypass graft and 54.9(14.8) ml/min in the aortocoronary bypass, which was not significantly different. Flow curve studies demonstrated early systolic flow reversal in the aortocoronary bypass, while the coronary-coronary bypass showed only forward flow. Mean(s.d.) flow in the proximal right coronary artery increased from 35.4(11.8) to 76.0(15.3) ml/min after opening the coronary-coronary bypass graft, which had a flow rate of 42.2(10.4) ml/min. It is concluded that the coronary-coronary bypass graft can provide nearly the same flow rate as aortocoronary bypass, and that the proximal right coronary artery has sufficient flow reserve for this technique.