Early and 8 year results of aortic valve replacement: a clinical study of 232 patients

The study concerns early and late results of aortic valve replacement (AVR) in 232 patients with aortic valve disease, using the Bj?rk-Shiley tilting-disc prosthesis. Of the 232, 27 patients had some evidence of mitral valve disease with valvulotomy having been undertaken in 7 previously, and in 12 at the time of the aortic valve replacement. Patients who underwent simultaneous mitral valve replacement and/or aorta coronary artery bypass grafting are not included in this analysis. To establish predictions of early death and late survival the patients were divided into two groups (A and B), taking 6 pre-operative risk factors into consideration: systolic pressure gradient greater than or equal to 100 mmHg; NYHA class IV; depressed left ventricular function (heart failure); previous valvulotomy of the aortic valve; advanced age (greater than or equal to 70 years) and surgery during the acute stage of bacterial endocarditis. In group A, consisting of 132 patients with no preoperative risk factors, early mortality was 1.5% (2/132). In group B, with 1 or more risk factors, early mortality amounted to 15% (15/100), (P less than 0.01). Subdividing group B into patients with one of the first three risk factors and patients with two or three of these risk factors, mortality was 12% (9/73) and 27% (6/22), respectively. Actuarially determined survival curves showed an 8-year survival rate of 84.2% for patients in group A and 59.6% for patients belonging to group B. Corrected for early mortality, however, the difference in late mortality is not significant. Analysis showed that early mortality was related to myocardial preservation: results for coronary perfusion and cardioplegic arrest were similar, but results were far less good when hypothermic ischaemic arrest was applied. Late results were less favourable in patients who had prior mitral valve disease not requiring mitral valve replacement at the time of AVR, or in those who developed mitral valve disease. The results allow the authors to conclude that AVR is a relatively safe procedure with a low operative mortality and few postoperative complications in patients with no 'risk factors'.     

Comparison of the precision of two standardized co-ordinate systems for the quantitation of brain anatomy: preliminary results

We assessed reproducible definition of two standardized co-ordinate systems for intersubject analysis of brain images. The baselines in the two co-ordinate systems were a modification of the canthomeatal (inCM) line and the anterior-posterior commissural )AC-PC) line. Axial spin-echo MR images of four subjects at 1.5T were used. Operator error was computed from the replicate analyses of two operators. The mCM line was determined by the lens of the eye and the internal auditory canal, and the AC-PC line was determined by the intersection of the AC and PC with the interhemispheric fissure. Reproducibility of the mCM markers (SD=0.59 mm) did not differ significantly from that of the AC-PC line (SD=0.68 mm). The measurement error of the angle of the baseline (), however, was more than 7 times as large for the AC-PC line as for the mCM line. An additional error affecting the rostrocaudal rotation of the co-ordinate systems, attributable to the distance between the anatomic markers, was 2.1 and 3.6° (3 mm and 5 mm slice thickness) for the mCM co-ordinate system and 8.2 and 11.0° (3 mm and 5 mm slice thickness) for the AC-PC system. The AC-PC line based co-ordinate system is therefore, less reproducible than the mCM line based system. this could be improved if a combination of axial and sagittal images were used for the definition of the AC-PC line.     

An improved model of galactosamine-induced fulminant hepatic failure in the pig

Fulminant hepatic failure is a serious condition with very high mortality. Development of new therapies designed to bridge the patient through the acute period of their disease has been hampered by the lack of a large animal model that closely reproduces the changes in humans. We have established an improved model of fulminant hepatic failure in the pig by administration of an aminosugar d-galactosamine hydrochloride. Galactosamine in a dose of 1.0 g/kg was dissolved in 5% dextrose in water (D5W) and given intravenously to seven young pigs weighing 8 to 15 kg. Seven control pigs received an equal volume of D5W alone. Two days prior to injection, a baseline ultrasound-guided liver biopsy was done in each pig under general anesthesia using isofluorane. Clinical data were recorded and blood for laboratory determinations was drawn at 0 h (baseline), 24 h, 48 h, and 72 h after infusion of galactosamine or D5W alone, under general anesthesia. Neurological data were recorded at the same intervals before inducing anesthesia. Galactosamine-treated animals showed 100% mortality. All of them died by 86 h after injection of galactosamine, with death resulting from fulminant hepatic failure characterized by marked increases in total bilirubin, liver enzymes, ammonia, and lactate; associated coagulopathy; hypoglycemia; and coma. Liver histology showed massive hepatocellular necrosis in all seven galactosamine-treated animals. This large and highly reproducible animal model appears promising for future evaluation of bioartificial liver support systems designed to treat fulminant hepatic failure in humans.     

Evaluation of oxidative DNA damage in human sperm and its association with male infertility

Recently, there is increasing evidence suggesting that oxidative sperm DNA damage is closely associated with impaired sperm function and male infertility. 8-Hydroxydeoxyguanosine (8-OHdG) is considered to be a precise and sensitive biomarker of oxidative DNA damage. The present study was thus designed to evaluate the extent of oxidative DNA damage in sperm and its association with male infertility by assaying the 8-OHdG levels in human sperm samples. A total of 114 subjects (60 infertile patients and 54 age-matched healthy workers) participated in this study. The level of 8-OHdG in sperm DNA was determined by high-performance liquid chromatography with electrochemical detection, and the conventional seminal parameters were also measured according to World Health Organization guidelines. It was found that the level of sperm 8-OHdG in infertile patients was significantly higher than that in healthy subjects (10.03 vs. 4.79 8-OHdG/10(5) dG; geometric mean, P < 0.001). The correlation between sperm 8-OHdG levels and conventional seminal parameters were also analyzed. There is a significant positive correlation between 8-OHdG and sperm head defects (r = 0.38, P < 0.001), whereas significant inverse correlations were noted for 8-OHdG with sperm density (r = -0.42, P < 0.001), total sperm number (r = -0.42, P < 0.001), sperm motility (r = -0.24, P < 0.01), and normal sperm morphology (r = -0.39, P < 0.001). Data from this study thus indicate that oxidative damage to sperm DNA may be important in the etiology of male infertility and that the assay of sperm 8-OHdG may have potential diagnostic value in the evaluation of sperm function and male fertility.     

Revision after total knee arthroplasty and unicompartmental knee arthroplasty in the medicare population

This study compares the relative risk of revision and associated risk factors after total or unicompartmental knee arthroplasty (TKA or UKA) in the Medicare population. A total of 61 767 TKA and 2848 UKA patients were identified. Reviewed data included type of treatment, gender, age, race, Charlson Index for comorbidity, length of stay, Medicare buy-in for socioeconomic status, region, and year. Unicompartmental knee arthroplasty patients were at increased risk for revision at 2 and 5 years. Those patients undergoing UKA were significantly more likely to require revision in the first 5 years as compared with those undergoing TKA. Risk factors contributing to TKA revision included younger male patients with higher comorbidities and lower socioeconomic status. About UKA, lower revision rates tend to favor those surgeons with higher volume.     

Surgical accuracy and clinical outcomes of image-free robotic-assisted total knee arthroplasty

Background

The development of total knee arthroplasty (TKA) for knee osteoarthritis (OA) has a good reputation for its effectiveness in reducing joint pain and improving range of motion. We aimed to review our early results using the image-free robotic-assisted technology in knee arthroplasty.

Methods

A total of 71 patients suffering from end-stage OA knee receiving TKA operated by robotic-assisted surgery between the years 2018 and mid-2021 were recruited. Clinical and radiological outcomes were compared with age and sex-matched control group (conventional TKA).

Results

The radiological outcome showed significantly more postoperative lower limb alignment outliers in conventional side than robotic-assisted sides. Postoperative knee scores were similar among both groups. Robotic-assisted TKA required a longer implantation time but a shorter hospital stay.

Conclusion

Robotic-assisted TKA achieved a lower rate of mechanical axis Outlier in the coronal and sagittal plane with a shorter hospital stay. Yet both methods achieve a similar functional outcome.     

Accurate Preoperative Localization of Insulinomas Avoids the Need for Blind Resection and Reoperation: Analysis of a Single Institution Experience with 17 Surgically Treated Tumors over 19 Years

Introduction  Presently, the need for and choice of preoperative localization tests for insulinomas remain controversial. We report the results from a single institution experience whereby the management policy adopted was that of accurate preoperative localization before surgical exploration. Materials and Methods  From 1990 to 2008, 17 patients with a clinical and biochemical diagnosis of an insulinoma who underwent surgery were retrospectively reviewed. The diagnosis of all insulinomas were confirmed pathologically. Results  All tumors were localized preoperatively and an average of 2.2 preoperative localization studies including 1.4 noninvasive studies and 0.8 invasive studies were utilized per patient. Invasive localization modalities were more sensitive (92%) than noninvasive modalities in localizing insulinomas (71%). Intra-arterial calcium stimulation with hepatic venous sampling was the most sensitive invasive modality (100%), whereas magnetic resonance imaging was the most sensitive noninvasive modality (63%). Fifteen of 17 tumors (88%) were localized intraoperatively via inspection/palpation and/or intraoperative ultrasonography. Both insulinomas which were not localized intraoperatively were localized correctly to the distal pancreas via preoperative transhepatic portal venous sampling. None of the patients required a blind resection or surgical reexploration for failed localization. All 17 patients underwent complete surgical resection which included eight enucleations and nine distal pancreatectomies with a cure rate of 94% (16/17) at a median follow-up of 35 (range, 1–217) months. The postoperative morbidity and long-term outcome of enucleation was similar to distal pancreatectomy despite a higher rate of microscopic margin involvement. Conclusion  Accurate preoperative localization of insulinomas is useful as it eliminates the need for blind distal pancreatectomy and avoids reoperation. Complete surgical resection is the treatment of choice, and whenever possible, a pancreas-sparing approach such as enucleation should be adopted.