Arterial patch angioplasty for reconstruction of proximal coronary artery stenosis.

BACKGROUND: Ostium patch angioplasty and reconstruction with an onlay patch consisting of pericardium or the saphenous vein is an alternative surgical technique for patients with proximal coronary artery stenosis. Previously described surgical techniques comprise anterior or posterior approaches. In this article we report our experience of using a segment of the proximal right internal mammary artery as an onlay patch for surgical angioplasty. METHODS: Between June 1997 and April 1999, 18 patients (9 men and 9 women) were subjected to surgical patch angioplasty of the left main coronary artery, 3 patients had an additional angioplasty performed on the proximal right coronary artery. The first 12 patients were operated with a posterior incision technique, and six subsequent patients by a new technique performed through an oblique incision into the left main stem after transsection of the ascending aorta. RESULTS: All patients had an uneventful postoperative course, and were fully rehabilitated without clinical symptoms of ischemic heart disease at mean follow-up of 10 months (range 1-23 months). Postoperative catheterization after six days showed excellent results with a widely open and funnel-shaped neoostium. CONCLUSIONS: The use of a proximal segment of the right internal mammary artery as an onlay patch for reconstructing proximal coronary artery lesions is safe with no complications. Although the posterior approach may be used to obtain excellent results, transsection of the ascending aorta gives an optimal visualization and mobilization of the left main coronary artery when performing surgical angioplasty.

Decreased pulmonary vascular resistance during nasal breathing: modulation by endogenous nitric oxide from the paranasal sinuses.

Nitric oxide is present in high concentration in the human nasal airways. During inspiration through the nose a bolus is transported to the lungs. In a randomized cross-over study the effect of two different patterns of breathing, nasal breathing and mouth breathing, was evaluated in 10 patients (mean age 65 years), breathing room air the morning of the first post-operative day after open heart surgery. Nasal breathing is defined as inspiration through the nose and expiration through the mouth, whilst mouth breathing is the converse of this: inspiration through the mouth and expiration through the nose. Pressure in the pulmonary artery and left atrium or pulmonary artery wedge was measured together with thermodilution cardiac output and arterial and mixed venous oxygenation and acid-base parameters. Pulmonary vascular resistance index (PVRI), venous admixture and alveolar-arterial gradient were calculated. Nasal breathing resulted in a lower PVRI, 256 dyn s cm-5 cm-2 vs. 287 (P < 0.01). The oxygen and carbon dioxide tension and pH of arterial and mixed venous blood, venous admixture and the alveolar-arterial gradient remained unchanged. The decreased level of PVRI during nasal breathing compared to that during mouth breathing supports the notion, that endogenous nitric oxide acts as an airborne messenger to modulate the pulmonary vascular tone during normal breathing.

Inhalation of nasally derived nitric oxide modulates pulmonary function in humans.

The vasodilator gas nitric oxide (NO) is produced in the paranasal sinuses and is excreted continuously into the nasal airways of humans. This NO will normally reach the lungs with inspiration, especially during nasal breathing. We wanted to investigate the possible effects of low-dose inhalation of NO from the nasal airways on pulmonary function. The effects of nasal and oral breathing on transcutaneous oxygen tension (tcPO2) were studied in healthy subjects. Furthermore, we also investigated whether restoring low-dose NO inhalation would influence pulmonary vascular resistance index (PVRI) and arterial oxygenation (PaO2) in intubated patients who are deprived of NO produced in the nasal airways. Thus, air derived from the patient's own nose was aspirated and led into the inhalation limb of the ventilator. In six out of eight healthy subjects tcPO2 was 10% higher during periods of nasal breathing when compared with periods of oral breathing. In six out of six long-term intubated patients PaO2 increased by 18% in response to the addition of nasal air samples. PVRI was reduced by 11% in four of 12 short-term intubated patients when nasal air was added to the inhaled air. The present study demonstrates that tcPO2 increases during nasal breathing compared with oral breathing in healthy subjects. Furthermore, in intubated patients, who are deprived of self-inhalation of endogenous NO. PaO2 increases and pulmonary vascular resistance may decrease by adding NO-containing air, derived from the patient's own nose, to the inspired air. The involvement of self-inhaled NO in the regulation of pulmonary function may represent a novel physiological principle, namely that of an enzymatically produced airborne messenger. Furthermore, our findings may help to explain one biological role of the human paranasal sinuses.

A comparison between morphine, meperidine and ketobemidone in continuous intravenous infusion for postoperative relief.

Morphine, meperidine and ketobemidone used in continuous i.v. infusion for postoperative pain relief were compared in a double-blind, controlled, prospective study in 81 consecutive consenting adult patients after open-heart surgery, with permission from the hospital ethics committee. During the first postoperative period, the infusion rates were fixed. Later on, when the infusion rate could be regulated according to individual patient needs, the variation in infusion rate was large, in accordance with earlier studies. No significant differences were demonstrated between the three analgesics with respect to efficacy of analgesia or side effects like shivering, nausea or vomiting. Respiratory depression following extubation was not observed. During shivering, there was a significant increase in the arterio-mixed venous difference of oxygen in all groups. The amounts of opioids used were relatively small compared to amounts used in patients following abdominal surgery. When interviewed some days after surgery, 18/74 patients remembered moderate pain and 11 severe pain during the stay in the ICU.