Partial versus full sternotomy for aortic valve replacement

Background. Recent trends suggest that smaller incisions reduce postoperative morbidity. This study tests the hypothesis that a partial upper sternotomy improves patient outcome for aortic valve replacement.

Methods. A group of 50 patients who underwent aortic valve surgery through a partial upper sternotomy (group I) were compared to 50 patients who underwent aortic valve replacement through a median sternotomy during the same time period (group II). The mean age (60 ± 2 versus 63 ± 2 years; mean ± SEM) and preoperative ejection fractions (53 ± 2 versus 54 ± 2) were similar. Operations were performed with central cannulation, and antegrade/retrograde blood cardioplegia.

Results. There was one death in each group. No differences were found in aortic occlusion time, mediastinal drainage, transfusion incidence, narcotic requirement, length of stay, or cost. The incidence of pleural and pericardial effusions was increased (18.4% versus 3.9%, p < 0.03), and the need for postoperative inotropic support was higher (38.7% versus 19.6%, p < 0.03) in the partial sternotomy group.

Conclusions. Aortic valve replacement can be performed through a partial sternotomy with results comparable to full sternotomy. The partial sternotomy offers a cosmetic benefit, but does not significantly reduce postoperative pain, length of stay, or cost.     

"True" parahiatal hernia: a rare entity radiologic presentation and clinical management

BACKGROUND: True parahiatal diaphragmatic hernias are rare entities that are sparsely accounted for in the literature. The current report is intended to depict the clinical profile and assess the feasibility of laparoscopic repair of parahiatal hernias. METHODS: We conducted a retrospective review of all patients diagnosed and treated for parahiatal hernias. Clinical presentation and radiological assessment, as well as operative findings and repair, are discussed. RESULTS: Of the 917 laparoscopic hiatal hernia repairs, 2 (0.2%) patients were identified with a parahiatal hernia. The presenting symptoms and preoperative testing were similar to those with more common paraesophageal hernias. Laparoscopic repair was successful in repairing the diaphragmatic defect and alleviating symptoms up to 4 years postoperatively. CONCLUSIONS: Parahiatal hernias of the diaphragm appear to be rare primary diaphragmatic defects. The clinical presentation of parahiatal hernias is often indistinguishable from the more common paraesophageal pathology. Laparoscopic repair of this rare entity can be safely and successfully accomplished in conjunction with antireflux surgical interventions when indicated.     

Immediate radiographic assessment following laparoscopic antireflux operations is unnecessary

Background: Laparoscopic antireflux operations (LAP) have become increasingly common for the treatment of gastroesophageal reflux disease (GERD). We sought to determine if routine postoperative barium contrast studies following LAP were clinically efficacious in identifying technical problems and life-threatening complications related to the surgical intervention. Methods: From January 1996 to December 1997, 112 barium studies were performed following 112 LAP procedures (47 male/65 female patients; mean age, 51 years) (group I). This group was compared to a subsequent cohort of 67 patients who underwent LAP between January 1998 and July 1998 without routine early postoperative barium contrast study (group II). Results: In 111/112 of the barium studies of group I, no radiographic abnormality was identified. The average length of stay (LOS) for these patients was 2.6 days. Routine barium studies were not utilized in group II. The average length of stay for patients in group II was 1.4 days. Twelve group II patients underwent early postoperative barium studies to evaluate suspicious clinical symptoms. None of these 12 postoperative studies identified important problems, nor did they alter the patients' clinical management. However, because of the barium study, their LOS was equivalent to those patients who had undergone routine barium study (2.4 days). There was an increase of $1451.80 in hospital charges in the group of patients who had a barium study, largely as a result of the increased LOS. Conclusion: The routine use of these studies results in increased patient charges and a prolongation in the length of hospital stay. Immediate postoperative barium studies following laparoscopic antireflux operations are of little value in determining important postoperative problems among patients undergoing LAO.     

Localization of mRNA encoding the indolamine synthesizing enzyme, hydroxyindole-O-methyltransferase, in chicken pineal gland and retina by in situ hybridization

Hydroxyindole-O-methyltransferase (HIOMT) is the enzyme that catalyzes the final step in the synthesis of the hormone melatonin. We have examined the localization of expression of the mRNA encoding HIOMT by in situ hybridization in the 3-day-old and adult chicken retina and pineal gland. The riboprobe utilized for this study was transcribed from the complete coding region of HIOMT cDNA synthesized from retina RNA and amplified by polymerase chain reaction (PCR). High levels of HIOMT mRNA were present in the pinealocytes of the pineal gland. In the retina, the hybridization signal was localized to the photoreceptors. The retinal photoreceptors of the 3-day-old chick displayed a much lower level of hybridization than did the photoreceptors of the adult chicken. This study strongly suggests that the photoreceptors are the sites of melatonin synthesis in the retina.     

Mutations of the flavin-containing monooxygenase gene (FMO3) cause trimethylaminuria, a defect in detoxication

Individuals with the recessive condition trimethylaminuria exhibit variation in metabolic detoxication of xenobiotics by hepatic flavin- containing monooxygenases. We show here that mutations in the human flavin-containing monooxygenase isoform 3 gene ( FMO3 ) impair N - oxygenation of xenobiotics and are responsible for the trimethylaminuria phenotype. Three disease-causing mutations in nine Australian-born probands have been identified which share a particular polymorphic haplotype. Nonsense and missense mutations are associated with a severe phenotype and are also implicated in impaired metabolism of other nitrogen- and sulfur-containing substrates including biogenic amines, both clinically and when mutated proteins expressed from cDNA are studied in vitro . These findings illustrate the critical role played by human FMO3 in the metabolism of xenobiotic substrates and endogenous amines.      

Idiopathic retinal degeneration in the dog: differential patterns of [3H]uridine incorporation and HIOMT-like immunoreactivity in surviving photoreceptors

Photoreceptor cell pathology was investigated in an 8-yr-old mixed-breed dog which had displayed visual symptoms of 1 month duration. An electroretinogram detected no light-evoked responses. Light and electron microscopic features showed marked thinning and atrophy of the outer both the tapetal and non-tapetal retina appeared to be involved. In the non-tapetal region, a majority of the rod inner segments were missing, while scattered mitochondria-filled stubby inner segments of cones were readily identified. Inner segments of both rods and cones were observed in the tapetal region. Photoreceptor outer segments were completely absent from the affected retina, and no outer segment debris was observed between the photoreceptor layer and the retinal pigmented epithelium (RPE). Autoradiographic analysis of 3-mm retinal disks from the degenerate retina following incubation with [3H]uridine indicated that only 61% +/- 13 S.D. of the remaining nuclei of rod photoreceptors were undergoing RNA synthesis, whereas more than 99% of cone nuclei incorporated the label. Normal and degenerate retina were also analysed for localization of hydroxyindole-O-methyltransferase (HIOMT)-like immunoreactivity. While the normal retina showed immunoreactivity in both rod and cone photoreceptors with more intense immunoreactivity present in cones, the degenerate retina showed HIOMT-like immunoreactivity only in the remaining cone photoreceptors. The results of this study of idiopathic photoreceptor degeneration of the canine retina suggest that although both photoreceptor types are involved, rods are more severely affected than cones.