Ultrasonographic anatomy of the sacrococcygeal region and ultrasound-guided epidural injection at the sacrococcygeal space in dogs.

Sacrococcygeal epidural anaesthesia allows selective desensitisation of the sacral plexus. Ultrasound is used for guidance in human anaesthesia to facilitate sacrococcygeal epidural injections. The aims of this study were to describe the sonographic appearance of the sacrococcygeal region in dogs and a technique for performing epidural injection at this location under ultrasound guidance. In the preliminary part of the study four cadavers were used to describe the sonoanatomy of the sacrococcygeal space and to develop the ultrasound-guided puncture technique. In the second phase of the study this technique was repeated in four dogs under general anaesthesia. In all dogs the sacrococcygeal space appeared as a circular hypoechoic region, located caudal to the sacral caudal articular processes, delimited by bony hyperechoic structures such as body and arch of the first caudal vertebra. Ultrasound guidance allowed the operator to visualise and position the spinal needle into the sacrococcygeal epidural space. No complications were reported during this procedure. Preliminary results indicate that ultrasound-guided sacrococcygeal epidural anaesthesia may be considered as an alternative to a blind approach technique.

Heart transplant in a patient with complete absence of the pericardium.

We report the case of a heart transplant in which the recipient patient had a total congenital absence of the pericardium. Associated with this, we found a major disproportion between the size of the recipient's mediastinal cavity and the size of the donor's heart. To prevent twisting of the great arteries, we placed the graft on the left diaphragm muscle and beneath the left lung, which resulted in an uneventful early and late postoperative course.

Coronary bilateral ostial enlargement using the saphenous vein in a patient with syphilitic aortitis.

A patient with tertiary syphilis presenting with bilateral coronary ostial lesions and aortic regurgitation underwent surgical reconstruction of the coronary ostia by the anterior approach with autogenous saphenous vein grafting and substitution of the aortic valve with a bovine bioprosthesis. The procedure was easily performed and had good outcomes both early and late. The rarity of the association of a lesion in both coronary ostia with aortic regurgitation in syphilis and the surgical technique employed are discussed.

Partial tricuspid valve transfer for repair of mitral insufficiency due to ruptured chordae tendineae.

BACKGROUND: A new technique is suggested for the reconstructive surgical treatment of mitral regurgitation. It involves partial transfer of the tricuspid valve of the patient to the mitral valve, in order to provide chordae to correct anterior leaflet prolapse of the mitral valve, secondary to rupture of the chordae tendineae. METHODS: From January 1991 to May 1997, 20 patients with mitral insufficiency due to rupture of the chordae were operated on. The prevailing cause was myxomatous degeneration (70%). Patients were in New York Heart Association functional class III and IV. RESULTS: There were no hospital deaths. Two patients were reoperated on. Eighteen patients (90%) are alive with their own valves (class I and II). Doppler echocardiogram mean values were: ejection fraction, 0.65; left atrial diameter, 4.2 cm; mitral area, 2.4 cm2; mitral transvalvular gradient, 3.3 mm Hg. No regurgitation or mild regurgitation was observed in 16 (94.1%) of the 17 cases evaluated. Mean tricuspid valvular area was 3.3 cm2. In all cases, no tricuspid regurgitation was present or it was mild. CONCLUSIONS: Partial transfer of the tricuspid valve to the mitral valve is an effective procedure for the surgical treatment of mitral valve insufficiency secondary to ruptured chordae tendineae of the anterior leaflet.

[A new reconstructive technique in cases of mitral insufficiency caused by the elongation of the chordae tendineae of the anterior cusp. A case report]. / Nova técnica reconstrutora na insuficiência mitral por alongamento das cordas tendíneas da cúspide anterior. Relato de caso.

A new technique is proposed for mitral incompetence due to elongated chordae tendineae of the anterior leaflet. It consists in shortening the chordae tendineae of the leaflet level. First, we make a longitudinal orifice in the anterior leaflet just near its free edge and the elongated chordae tendineae. Through the orifice and with the help of a micro nerve hook we pull the elongated chordae the necessary to keep the anterior leaflet in the same level of the posterior leaflet. The orifice is then closed with a polipropilene 5-0 suture. The mitral annuloplasty was performed with a Gregori IMC prosthetic ring. The excellent clinical and laboratorial data suggest that mitral insufficiency due to elongated chordae tendineae can be corrected by this technique.

Cloning multiple copies of a DNA segment.

A method for self-ligation of DNA segments, which is based on the rotational non-equivalence of ends produced by AvaI cleavage, has been developed. Using this method and an initiator molecule to encourage the formation of long polymers, we have obtained a plasmid containing 34 repeats of a 123-bp rat DNA segment. All of the repeats are in the same orientation, and the plasmid is quite stable. It should be possible to polymerize any DNA segment by this method. Potential uses of the procedure include production of large amounts of small, homogeneous DNAs for physical studies such as X-ray crystallography, and increasing the expression of cloned genes in bacteria.