Modulation of NO Bioavailability by Temporal Variation of the Cell-Free Layer Width in Small Arterioles

The cell-free layer exhibits dynamic characteristics in the time domain that may be capable of altering nitric oxide (NO) bioavailability in small arterioles. However, this effect has not been fully elucidated. This study utilized a computational model on NO transport to predict how temporal variations in the layer width could modulate NO bioavailability in the arterioles. Data on the layer width was acquired from high-speed video recordings in arterioles (ID = 48.4 ± 1.8 μm) of the rat cremaster muscle. We found that when wall shear stress response was not considered, the layer variability could lead to a slight decrease (1.6–6.6%) in NO bioavailability that was independent of transient changes in NO scavenging rate. Conversely, the transient response in wall shear stress and NO production rate played a dominant role in reversing this decline such that a significant augmentation (5.3–21.0%) in NO bioavailability was found with increasing layer variability from 24.6 to 63.8%. This study highlighted the importance of the temporal changes in wall shear stress and NO production rate caused by the layer width variations in prediction of NO bioavailability in arterioles.     

Assessment and validation of CT scanogram to compare per-operative and post-operative mechanical axis after navigated total knee replacement

Our objective was to assess and validate low-dose computed tomography (CT) scanogram as a post-operative imaging modality to measure the mechanical axis after navigated total knee replacement. A prospective study was performed to compare intra-operative and post-operative mechanical axis after navigated total knee replacements. All consecutive patients who underwent navigated total knee replacement between May and December 2006 were included. The intra-operative final axis was recorded, and post-operatively a CT scanogram of lower limbs was performed. The mechanical axis was measured and compared against the intra-operative measurement. There were 15 patients ranging in age from 57 to 80 (average 70) years. The average final intra-operative axis was 0.56° varus (4° varus to 1.5° valgus) and post-operative CT scanogram axis was 0.52° varus (3.1° varus to 1.8° valgus). The average deviation from final axes to CT scanogram axes was 0.12° valgus with a correlation coefficient of 0.9. Our study suggests that CT scanogram is an imaging modality with reasonable accuracy for measuring mechanical axis despite significantly low radiation. It also confirms a high level of correlation between intra-operative and post-operative mechanical axis after navigated total knee replacement.

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Résumé  Cette étude a pour but d’analyser et d’évaluer les images scanner et les modalités des clichés post-opératoires après prothèse totale du genou implantée avec navigation. Matériel et méthode: une étude prospective a été réalisée pour comparer les axes mesurés en per et post-opératoire, après navigation, chez les patients ayant bénéficié d’une prothèse totale du genou avec navigation et inclus de mai à décembre 2006. Les axes per et post-opératoires ont été rapportés et comparés avec l’axe mécanique obtenu et mesuré en per-opératoire. Résultats: 15 patients d’age moyen de 70 ans (57 – 80 ans) ont été analysés. L’axe final per-opératoire a été de 0.52° varus (4° à 1,5°) et, l’axe post-opératoire mesuré par scanner a été de 0.52° varus (3,1° à 1,8°). La déviation axiale médiane est de 0.12° valgus avec un coefficient de corrélation de 0,9. En conclusion, notre étude permet de penser que le scanner est une modalité d’évaluation raisonnable de mesure de l’axe mécanique en dépit d’une irradiation significative mais néanmoins assez basse. Cette étude permet également de confirmer un haut niveau de corrélation entre la mesure de l’axe per-opératoire et la mesure de l’axe post-opératoire dans les prothèses totales du genou avec navigation.

     

Evaluation of the clinical signs of anterior cruciate ligament and meniscal injuries

Background:

The diagnostic accuracy of anterior drawer (AD) sign, Lachman test and the pivot shift test for anterior cruciate ligament injury and McMurray test for medial and lateral meniscus is varied with sensitivity and specificity ranging from 2 to 100%. Generally, it is accepted that the pivot shift test is the most specific test to diagnose anterior cruciate ligament (ACL) tears and that the Lachman test is more sensitive than AD sign. This study was undertaken to calculate the sensitivity, specificity, positive predictive value, negative predictive value, and efficiency for the above-mentioned diagnostic tests.

Materials and Methods:

Twenty-eight male patients with clinical ACL injury were examined in the outpatient department and under anaesthesia, the findings were compared with arthroscopy.

Result:

The sensitivity and specificity for the Lachman test, AD sign and pivot shift test performed in the outpatient setting are 78.6 and 100%, 89.3 and 100%, and 75 and 100%, respectively. The sensitivity and specificity for the Lachman test, AD sign, and pivot shift test performed under anesthesia are 92.9 and 100%, 92.9 and 100%, and 100 and 100%, respectively. The sensitivity and specificity of the McMurray test for medial and lateral meniscus were 35.7 and 85.7% and 22.2 and 100%, respectively.

Conclusion:

The Lachman test, AD sign and pivot shift test are highly specific tests to diagnose ACL laxity in a non-acute setting; pivot shift test under anesthesia is the most sensitive and specific test for diagnosing ACL laxity in a non-acute setting and the McMurray test is not a sensitive test to diagnose meniscal injury in the presence of ACL injury.     

Laparoscopic repair of recurrent groin hernia: results of a prospective study

Background  Recurrences continue to be seen after repair of inguinal hernias. The repair of these recurrent hernias is a more complex and demanding procedure, with a high re-recurrence rate. Definite advantage has been demonstrated with endoscopic repair of these hernias. Methods  The results for this prospective study from January 2003 to December 2006 were evaluated after laparoscopic repair of 65 recurrent hernias in 61 patients. The patients were followed up for 1 year. Longer follow-up evaluation was performed for the patients who underwent surgery in the initial 3 years. Results  In this study, 37 recurrent hernias were managed using the transabdominal preperitoneal technique (TAPP) technique and 28 using the totally extraperitoneal (TEP) technique. There was no conversion and no cases of postoperative wound infection. Of the 12 metachronous hernias repaired simultaneously, 3 were occult. Seroma developed in five patients. At a follow-up assessment after 1 year, one patient had groin pain, and there was one re-recurrence. A longer follow-up period with a mean of 35.11 months failed to show any new re-recurrence. Conclusions  Laparoscopic repair of recurrent inguinal hernia is safe and effective. The morbidity and recurrence rates for the procedure are as low as for laparoscopic repair of primary hernias. Laparoscopic repair should be the gold standard for these hernias.     

Abdominal Cocoon: Clinical Presentation, Diagnosis, and Management

A 15-year-old girl presented with features suggestive of sub-acute intestinal obstruction (SAIO) with a palpable abdominal lump. Contrast-enhanced computed tomogram (CECT) abdomen revealed congregated small gut loops confined to a single area and encased in a thick membrane suggestive of abdominal cocoon. On laparotomy, a thick white membrane was found encasing most of the small gut. The cocoon was excised releasing the encased small bowel. The patient was relieved of her symptoms following surgery. Histopathology of excised cocoon membrane revealed granulomatous inflammation consistent with tuberculosis. The patient was discharged on ninth postoperative day with advice to take anti-tuberculosis drugs for 6 months. The possibility of abdominal cocoon should be considered in patients with SAIO and abdominal lump. Abdominal cocoon being a rare condition, CECT is useful in clinching the diagnosis and planning elective surgery in experienced hands.     

Comparative Analysis of Outcomes in Living and Deceased Donor Liver Transplants for Primary Sclerosing Cholangitis

Introduction  Primary sclerosing cholangitits (PSC) is a progressive fibrosing cholangiopathy eventually leading to end-stage liver disease (ESLD). While literature for deceased donor liver transplantation (DDLT) for PSC abounds, only a few reports describe live donor liver transplant (LDLT) in the setting of PSC. We present a single-center experience on survival outcomes and disease recurrence for LDLT and DDLT for ESLD secondary to PSC. Aim  The aim of this study was to analyze survival outcomes and disease recurrence for LDLT and DDLT for ESLD secondary to PSC. Patients and Methods  A retrospective review of 58 primary liver transplants for PSC-associated ESLD, performed between May 1995 and January 2007, was done. Patients were divided into two groups based on donor status. Group 1 (n = 14) patients received grafts from living donors, while group 2 (n = 44) patients received grafts from deceased donors. An analysis of survival outcomes and disease recurrence was performed. Recurrence was confirmed based on radiological and histological criteria. Results  Recurrence of PSC was observed in four patients in LDLT group and seven in DDLT group. Retransplantation was required in one patient in LDLT group and nine patients in DDLT group. One patient (7%) among LDLT and six patients (14%) among DDLT died. The difference in patient and graft survival was not statistically significant between the two groups (patient survival, p = 0.60; graft survival, p = 0.24). Conclusion  This study demonstrates equivalent survival outcomes between LDLT and DDLT for PSC; however, the rate of recurrence may be higher in patients undergoing LDLT.