Variation in the learning curves of general surgery residents performing arteriovenous fistulas.

BACKGROUND: An arteriovenous fistula (AVF), performed for hemodialysis access, provides one of the few remaining opportunities for general surgery residents to perform an open vascular anastomosis (VA). Limited data exist regarding the learning curve of residents performing this procedure. The objective of this study was to determine how residents improve in performance of VA by implementing real-time tracking of anastomosis time as well as technical errors. STUDY DESIGN: From April 2012 to January 2014, we conducted a prospective intraoperative assessment of 9 postgraduate year 3 general surgery residents during the performance of AVFs using a checklist of common errors in VA. Time for AVF anastomosis completion and number and types of technical errors during anastomosis were recorded. Primary end points were the change in anastomosis time and change in technical errors over time. RESULTS: A total of 86 AVFs were performed and assessed intraoperatively. Each resident performed a median of 10 AVFs (interquartile range [IQR]: 7-11). The mean anastomosis time was 18.1 minutes. The mean number of technical errors was 13.8 per case. Overall, for every additional AVF performed, mean anastomosis time decreased by 0.63 minutes (95% CI: 0.45-0.81, p < 0.0001) and the mean number of technical errors decreased by 1.0 (95% CI: 0.7-1.3, p < 0.0001). The greatest improvement in overall errors (mean difference = 7.9, p = 0.03) and time (mean difference = 4.7min, p = 0.03) occurred after the performance of 3 AVFs. However, when analyzed by individual resident, the R(2) value for anastomotic time by number of AVFs performed ranged from 0.01 to 0.69. Similarly, for technical errors, the R(2) value by number of AVFs performed ranged from 0.04 to 0.62. CONCLUSIONS: In novice surgical residents performing AVFs, improvement in VA skill can readily be tracked via anastomosis time and technical errors. Collectively, there is a strong association between number of cases performed and reduction in time and errors. However, individually, the number of cases completed did not correlate well with time and errors. These findings suggest that for VA skills, determining progression from novice to competence cannot rely on case volume but rather needs to be individualized.

Internal fixation of diaphyseal fractures of the forearm: a retrospective comparison of hybrid fixation versus dual plating.

OBJECTIVES: To compare open reduction and internal fixation using dual plating to a hybrid fixation construct with intramedullary nailing of the ulna and plate fixation of the radius in both-bone forearm fractures. DESIGN: Retrospective comparison study. SETTING: Level I trauma center. PATIENTS: A total of 56 skeletally mature individuals treated surgically for acute both-bone forearm fractures between July 2005 and December 2009. Monteggia, Galeazzi, and pathologic fractures, patients treated with external fixation and patients with traumatic brain injuries were excluded. INTERVENTION: Twenty-seven patients were treated with dual plate fixation, and 29 patients were treated using a hybrid fixation construct. MAIN OUTCOME MEASURES: Time to union, range of motion as assessed using a Grace and Eversmann score, and presence of complications. RESULTS: There was no significant difference in either time to union or Grace and Eversmann scores between the 2 groups. There was 1 nonunion in each of the 2 groups. Nine overall complications, outside nonunions, were reported: 5 in the dual plating group and 4 in the hybrid fixation group. CONCLUSIONS: Hybrid fixation, using open reduction and internal fixation with a plate-and-screw construct on the radius and closed--or minimally open--reduction and interlocked intramedullary fixation of the ulna, is an acceptable method for treating both-bone diaphyseal forearm fractures in skeletally mature patients. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Current methods of adipogenic differentiation of mesenchymal stem cells.

There has been a recent increase in our understanding in the isolation, culture, and differentiation of mesenchymal stem cells (MSCs). Concomitantly, the availability of MSCs has increased, with cells now commercially available, including human MSCs from adipose tissue and bone marrow. Despite an increased understanding of MSC biology and an increase in their availability, standardization of techniques for adipogenic differentiation of MSCs is lacking. The following review will explore the variability in adipogenic differentiation in vitro, specifically in 3T3-L1 and primary MSCs derived from both adipose tissue and bone marrow. A review of alternative methods of adipogenic induction is also presented, including the use of specific peroxisome proliferator-activated receptor-gamma agonists as well as bone morphogenetic proteins. Finally, we define a standard, commonly used adipogenic differentiation medium in the hopes that this will be adopted for the future standardization of laboratory techniques--however, we also highlight the essentially arbitrary nature of this decision. With the current, rapid pace of electronic publications, it becomes imperative for standardization of such basic techniques so that interlaboratory results may be easily compared and interpreted.

Amyloidosis-associated neurotrophic keratopathy precipitated by overcorrected blepharoptosis.

PURPOSE: To describe amyloidosis-associated neurotrophic keratopathy. METHODS: In this interventional case report, we describe the clinical findings of a patient with amyloidosis-associated neurotrophic keratopathy, precipitated by exposure from overcorrected blepharoptosis. RESULTS: A 70-year-old woman with a history of amyloidosis was referred with bilateral eyelid retraction 1 month after levator aponeurosis advancement surgery. Examination demonstrated visual acuities of count-fingers OD and 20/400 OS and severe corneal epithelial irregularity with diffuse fluorescein staining. She had marked eyelid retraction with 5-mm right and 3-mm left superior scleral show and incomplete closure. Corneas were anesthetic, and neurologic examination was notable for peripheral sensory loss. Despite eyelid position normalization, the corneal abnormalities progressed to large epithelial defects refractory to aggressive lubrication, punctal occlusion, bandage contact lenses, extended patching, and ultimately tarsorrhaphy consistent with neurotrophic keratopathy. One year postoperatively, the epithelial disease persists. CONCLUSION: Neurotrophic keratopathy can occur in association with amyloidosis and may be precipitated by exposure related to blepharoptosis repair.

Hypotony maculopathy after eyelid massage for overcorrected blepharoptosis.

A 57-year-old woman with a history of left eye trabeculectomy was evaluated for gradual ipsilateral visual loss. Several months prior, she had undergone levator advancement of the left upper eyelid. For management of resulting retraction, she was instructed to "massage" her eyelid. Examination was notable for left eye visual acuity of 20/200 and an intraocular pressure of 5 mm Hg. On fundoscopic examination, the macula was edematous with multiple folds, consistent with hypotony maculopathy. Two years later, after obliteration of the bleb and placement of a Seton valve, the intraocular pressure has increased to 8 mm Hg with an acuity correctable to 20/50. Ocular hypotony may result from digital eyelid massage in patients with filtering blebs. Clinicians should bear this in mind when managing patients with eyelid retraction after blepharoptosis repair.