Robotic uretero-ureterostomy of the retrocaval ureter without excision of the retrocaval segment

Robotic reconstruction of the retrocaval ureter is gaining momentum as the method of choice for surgically treating this rare condition. Maintaining the retrocaval ureteric segment further facilitates the procedure. We report a case of a 23-year-old man who underwent intraperitoneal robotic resection anastomosis and repositioning of the retrocaval ureter. We also discuss the advantages of this technique.     

Contribution of different mechanisms to the resistance to fluoroquinolones in clinical isolates of Salmonella enterica

ObjectivesTo study the potential factors include gene mutation, efflux pump and alteration of permeability associated with quinolone-resistance of Salmonella enterica strains isolated from patients with acute gastroenteritis and to evaluate the degree of synergistic activity of efflux pump inhibitors when combined with ciprofloxacin against resistant isolates.MethodsAntimicrobial resistance patterns of fifty-eight Salmonella isolates were tested. Five isolates were selected to study the mechanism of resistance associated with quinolone group, including mutation in topoisomerase-encoding gene, altered cell permeability, and expression of an active efflux system. In addition, the combination between antibiotics and efflux pump inhibitors to overcome the microbial resistance was evaluated.ResultsFive Salmonella isolates totally resistant to all quinolones were studied. All isolates showed alterations in outer membrane proteins including disappearance of some or all of these proteins (Omp-A, Omp-C, Omp-D and Omp-F). Minimum inhibitory concentration values of ciprofloxacin were determined in the presence/absence of the efflux pump inhibitors: carbonyl cyanide m-chlorophenylhydrazone, norepinephrin and trimethoprim. Minimum inhibitory concentration values for two of the isolates were 2–4 fold lower with the addition of efflux pump inhibitors. All five Salmonella isolates were amplified for gyrA and parC genes and only two isolates were sequenced. S. Enteritidis 22 had double mutations at codon 83 and 87 in addition to three mutations at parC at codons 67, 76 and 80 whereas S. Typhimurium 57 had three mutations at codons 83, 87 and 119, but no mutations at parC.ConclusionsEfflux pump inhibitors may inhibit the major AcrAB-TolC in Salmonella efflux systems which are the major efflux pumps responsible for multidrug resistance in Gram-negative clinical isolates.     

Regulation of alloantigen-mediated T-cell proliferation by endogenous interferon-gamma: implications for long-term allograft acceptance.

BACKGROUND: Recent data suggest that interferon (IFN)-gamma is not an essential mediator of acute rejection but, instead, is critical for the induction of long-term allograft acceptance. The in vivo mechanisms by which endogenous IFN-gamma regulates the alloimmune response and thus facilitates the induction of long-term allograft survival are not known. METHODS: We examined long-term cardiac and skin allograft survival, alloantigen-induced T-cell proliferation, and alloantigen-induced T-cell apoptosis in wild-type (IFN-gamma+/+) and IFN-gamma gene-knockout (IFN-gamma-/-) mice treated with either B7-CD28 T-cell costimulation blockade alone or B7-CD28 T-cell costimulation blockade combined with donor splenocyte transfusion. RESULTS: We found that IFN-gamma is essential for long-term allograft survival induced by treating mice with either B7-CD28 T-cell costimulation blockade alone or B7-CD28 T-cell costimulation blockade combined with donor splenocyte transfusion. Alloantigen-induced T-cell proliferation in vivo was significantly greater in IFN-gamma-/- mice than in IFN-gamma+/+ mice, and T-cell costimulation blockade abrogated alloantigen-induced T-cell proliferation in wild-type mice but failed to do so in mice that lack IFN-gamma. In contrast, alloantigen-induced T lymphocyte apoptosis in vivo did not differ between IFN-gamma+/+ and IFN-gamma-/- mice, and T-cell costimulation blockade enhanced alloantigen-induced T-cell apoptosis in both mouse strains. CONCLUSIONS: These data suggest that endogenous IFN-gamma facilitates the induction of long-term allograft survival by limiting the proliferation of alloactivated T lymphocytes. The data also suggest that B7-CD28 T-cell costimulation blockade exerts immunosuppressive actions by inhibiting the proliferation of activated T lymphocytes and by promoting their apoptosis.     

Elective hip and knee arthroplasty and the effect of rivaroxaban and enoxaparin thromboprophylaxis on wound healing

Introduction

Rivaroxaban is the first licensed oral direct inhibitor of factor Xa. Recent studies from the RECORD trials suggest rivaroxaban has superior efficacy compared to enoxaparin in preventing venous thromboembolism (VTE) with no significant increase in the major bleeding risk. Concerns remain regarding the incidence of minor bleeding, consequent delayed wound healing and subsequent risk of infection. The aim of this observational study was to assess the incidence of post-operative complications in patients receiving either rivaroxaban or enoxaparin thromboprophylaxis following elective hip and knee arthroplasty.

Methods

A total of 258 patients undergoing elective total hip or knee arthroplasty within one NHS Trust were included. A total of 202 subjects (mean age, 70.7 years ± 10.0, 43 % men) received a daily dose of 10 mg of oral rivaroxaban and 56 (mean age, 70.9 years ± 9.8, 39 % men) had a daily subcutaneous injection of 40 mg of enoxaparin as thromboprophylaxis. Endpoints included VTE (deep vein thrombosis and pulmonary embolism), haemorrhagic wound complications, hospital re-admission, requirement for blood transfusion, minor and major bleeding and death.

Results

There were no significant differences in the incidence of VTE, requirement for blood transfusion and readmission rate between rivaroxaban and enoxaparin-treated patients. The incidence of minor bleeding (2.0 vs. 0 %) and haemorrhagic wound complications (5.0 vs. 1.8 %) were non-significantly higher in the rivaroxaban-treated group. There were no cases of pulmonary embolism, major bleeding or death in either group.

Conclusion

Our experience with rivaroxaban in elective hip and knee arthroplasty showed no significant difference in the incidence of VTE or major bleeding. There was, however, a tendency to greater risk of minor bleeding and wound complications that were largely haemorrhagic in nature, which may have reached significance in a larger study.     

Biomechanical comparison of patellar tendon repairs in a cadaver model: an evaluation of gap formation at the repair site with cyclic loading

BACKGROUND: Ruptures of the patellar tendon are rare injuries. Surgical treatment for this injury is mandatory. HYPOTHESIS: Gap formation does not differ between the three patellar tendon repair techniques. STUDY DESIGN: Controlled laboratory study. METHODS: Twelve fresh-frozen cadaveric knees were used to compare three techniques of patellar tendon repairs. The standard suture repair used two Krackow sutures placed in the avulsed patellar tendon, passed through transpatellar drill holes, and secured with the knee in 30 degrees of flexion. In the second group, suture repair was augmented with a No. 5 Ethibond suture. In the third group, suture repair was augmented with a 2.0 Dall-Miles cable. Testing was performed with the specimens mounted to a custom knee jig with the tibia free, simulating the knee moment of a 70-kg person. Each knee was then cycled 250 times at 0.25 Hz. RESULTS: Gap formation across the standard suture repair averaged 7.3 mm; across the suture augmentation and cable augmentation groups it averaged 4.9 mm and 3.5 mm, respectively. CONCLUSIONS: Augmentation of patellar tendon avulsions can decrease gap formation at the repair site, allowing early mobilization. Clinical Relevance: Gap formation seen in repair without augmentation could lead to clinical failure with resultant patella alta and extensor mechanism lag.     

Vertebroplasty increases compression of adjacent IVDs and vertebrae in osteoporotic spines

Background contextApproximately 25% of vertebroplasty patients experience subsequent fractures within 1 year of treatment, and vertebrae adjacent to the cemented level are up to three times more likely to fracture than those further away. The increased risk of adjacent fractures postaugmentation raises concerns that treatment of osteoporotic compression fractures with vertebroplasty may negatively impact spine biomechanics.PurposeTo quantify the biomechanical effects of vertebroplasty on adjacent intervertebral discs (IVDs) and vertebral bodies (VBs).Study designA biomechanics study was conducted using cadaveric thoracolumbar spinal columns from elderly women (age range, 51–98 years).MethodsFive level motion segments (T11–L3) were assigned to a vertebroplasty treated or untreated control group (n=10/group) such that bone mineral density (BMD), trabecular architecture, and age were similar between groups. Compression fractures were created in the L1 vertebra of all specimens, and polymethylmethacrylate bone cement was injected into the fractured vertebra of vertebroplasty specimens. All spine segments underwent cyclic axial compression for 115,000 cycles. Microcomputed tomography imaging was performed before and after cyclic loading to quantify compression in adjacent VBs and IVDs.ResultsCyclic loading increased strains 3% on average in the vertebroplasty group when compared with controls after 115,000 cycles. This global strain manifested locally as approximately fourfold more compression in the superior VB (T12) and two- to fourfold higher axial and circumferential deformations in the superior IVD (T12–L1) of vertebroplasty-treated specimens when compared with untreated controls. Low BMD and high cement fill were significant factors that explained the increased strain in the vertebroplasty-treated group.ConclusionsThese data indicate that vertebroplasty alters spine biomechanics resulting in increased compression of adjacent VB and IVD in severely osteoporotic women and may be the basis for clinical reports of adjacent fractures after vertebroplasty.     

Clinical comparison between double-row and transosseous-equivalent repairs for medium to large size rotator cuff tears

Background

The transosseous-equivalent (TOE) repair of the rotator cuff tears was invented to make up for several shortcomings of the double-row (DR) repair. However, no studies have compared the clinical aspects of the DR repair and the TOE technique, supporting the superior results of the TOE technique over the DR repair, including the benefit of minimizing surgical steps. We asked whether differences existed between the two repairs regarding clinical outcomes, time and costs.

Materials and methods

Subjects included 55 using the DR repair and 119 using the TOE repair for the medium to large sized rotator cuff tears. Clinical outcomes were measured with a Visual Analog Scale, American Shoulder and Elbow Surgeons score, Constant score, and shoulder strength. For practical aspects, operative time and number of suture anchors used for the medial and lateral rows were compared.

Results

Both repairs brought substantial improvements in pain and function. However, significant differences were not detected between the repairs in all the clinical measurements. Regarding operative time and costs, in the medium size tears, a statistical difference was found only in the anchors used for the lateral row. In the large size tears, the DR repair required more operation time than the TOE repair, while the TOE repair used more anchors for the lateral row.

Conclusion

This study failed to demonstrate clinical differences between the techniques. However, when stratifying rotator cuff tears according to the tear sizes, significant differences were found in operative time and cost: the DR repair had the advantage of cost effectiveness by saving anchors for the lateral row, while the TOE repair required less operative time with more anchors used for the lateral row in the large size tears. This finding provides evidence to support the use of the TOE repair to reduce surgical steps.