Less invasive techniques for mitral valve surgery.

OBJECTIVE: Minimally invasive surgical techniques aim at reducing the consequences of currently used large incisions, such as bleeding, pain, and risk of infection. Although this new approach developed rapidly in coronary surgery, it remains questionable in mitral valve surgery. This article reports the longest experience with minimally invasive mitral valve surgery, with particular attention to approach and techniques. METHODS: From February 1996, the date of the first case of minimally invasive mitral valve reconstruction, to April 1997, 22 patients with a mean age of 54 +/- 2.7 years were subjected to mitral valve surgery performed with less invasive techniques. Exposure of the mitral valve was achieved through a minithoracotomy (n = 12) or a ministernotomy (n = 10). Video assistance was used in all cases. Peripheral arterial cannulation (n = 21) and venous drainage (n = 22) were used in most cases. RESULTS: In this series, valve surgery consisted in 19 repairs, two replacements, and one closure of a periprosthetic leak. In two cases it was necessary to convert to a larger incision. The average duration of cardiopulmonary bypass was 157 +/- 8.2 minutes, ventilatory assistance 16 +/- 4.6 hours, and intensive care unit stay 2.1 +/- 0.4 days. Two patients required reoperation for bleeding and another for early recurrence of mitral valve regurgitation. There were no deaths and all patients were discharged with normal valve function. At most recent follow-up, all patients were in functional class I, with resumption of normal activity. CONCLUSION: Mitral valve surgery can be performed safely by means of less invasive techniques, but with increased technical difficulty. A low asymmetric median sternotomy seems preferable to an anterior thoracotomy.

Pulmonary bipartitioning and lobar transplantation: a new approach to donor organ shortage.

The scarcity of small donors has significantly limited lung transplantation for pediatric and small adult patients. Use of single lobes procured from size-unmatched donors has overcome this difficulty, but only in a few selected cases and, in addition, it represents a waste of lung tissue. In an animal model we have shown that it is possible to divide one lung with careful partitioning of the vascular and bronchial structures and thus obtain two viable lobar grafts suitable for bilateral implantation in a smaller animal. We have now applied this procedure clinically in seven patients operated on between May 1993 and November 1994. The indications were cystic fibrosis in three children, primary pulmonary hypertension in two adults, bronchiectasis in one, and idiopathic pulmonary fibrosis in one. There were three children aged 13 to 17 years (median 14) and four adults aged 40 to 53 years (median 45). There was a 46% to 50% discrepancy for weight between recipient and donor and a 12% to 17% discrepancy for height. The surgical technique consisted of careful partitioning of the left donor lung, bilateral anterior thoracotomy in the recipient, and, with the use of cardiopulmonary bypass, implantation of the lower lobe in the left hemithorax and the upper lobe in the right hemithorax. Vascular and bronchial connections were facilitated by leaving a long pedicle on the recipient side. The pulmonary artery anastomosis for the donor left upper lobe was done with the "fissure" side of the artery to ensure an anastomosis without tension. An end-to-end bronchial anastomosis overcame the problem of size discrepancy. Six patients are alive and well 10 to 27 months (median 19) after operation. One patient with cystic fibrosis died of systemic aspergillosis infection. All were discharged from the hospital within the first or second postoperative month. No technical problems were identified: repeated bronchoscopy has demonstrated satisfactory healing without early stricture formation. All patients remain well subjectively with good exercise tolerance and all patients achieve greater than 70% of predicted values of forced expiratory volume in 1 second. Perfect adaptation of the transplanted lobes to the recipient pleural space has been demonstrated by postoperative computed tomographic scan. In conclusion, bilateral lobar transplantation from a single donor lung is possible in small adults or children when there is a large size discrepancy with the donor. This may help resolve the problem of donor availability in the pediatric population.

The "physio-ring": an advanced concept in mitral valve annuloplasty.

BACKGROUND: A new annuloplasty ring has been developed with the aim of adding flexibility to the remodeling annuloplasty concept. Here we report its clinical use with special emphasis on segmental valve analysis and valve sizing. METHODS: From October 1992 through June 1994, 137 patients aged 4 to 76 years (mean age, 49.1 years) were operated on. The main causes of mitral valve insufficiency were degenerative, 90; bacterial endocarditis, 15; and rheumatic, 13. The indication for operation was based on the severity of the mitral valve insufficiency (90 patients were in grade III or IV) rather than on functional class (60 patients were in class III or IV). At echocardiography 6 patients had normal leaflet motion (type I), 119 leaflet prolapse (type II), and 12 restricted leaflet motion (type III). Surgical repair was carried out using Carpentier techniques of valve reconstruction. In 3 patients, inadequate ring sizing was responsible for systolic anterior motion of the anterior leaflet diagnosed by intraoperative echo. The valve was replaced in 2 patients. There were three hospital deaths, no late deaths, one reoperation for recurrent mitral valve insufficiency due to chordal rupture 1 month after repair, one reoperation for atrial thrombus formation 5 months after repair, one anticoagulant-related hemorrhage, and one thromboembolic episode. RESULTS: Mid-term follow-up between 6 and 18 months was available in 94 patients. Echocardiography showed trivial or no regurgitation in 93.2% of the patients and minimal regurgitation in 6.8%. The average transmitral diastolic gradient was 3.55 +/- 1.93 mm Hg. Left ventricular end-systolic diameter and volume decreased postoperatively, demonstrating an improved left ventricular function. CONCLUSIONS: This preliminary experience has provided promising results and allowed us to define the indications of the Physio-Ring versus the classic ring. It has also shown that valve sizing and proper ring selection are of primary importance.

Biatrial inferior transseptal approach to the mitral valve.

The standard surgical approach to the mitral valve is via a longitudinal incision in the left atrium. This is applicable in the vast majority of patients. In cases of small left atrium with poor exposure the standard incision may be modified. We report a biatrial inferior transseptal approach that we have employed in 25 patients over a 2-year period. The technique is simple to execute and is without risk to surrounding structures.