Trephine Minimally Invasive Procedure for Pilonidal Sinus.

BACKGROUND: Pilonidal sinus is a chronic, inflammatory condition. Controversy exists regarding the best surgical management for pilonidal sinus, including the extent of excision and type of closure of the surgical wound. OBJECTIVES: To assess the short- and long-term outcomes and success rate of the trephine procedure for the treatment of pilonidal sinus. METHODS: A retrospective observational cohort study was conducted at a single center. Patients who underwent trephine procedure between 2011 and 2015 were included. Data collection included medical records review and a telephone interview to establish long-term follow-up. RESULTS: A total of 169 patients underwent the trephine technique for the repair of pilonidal sinus. Follow-up included 113 patients, median age 20 years. Initial postoperative period, 35.6% recalled no pain and 58.6% reported a mild to moderate pain. Postoperative complications included local infection (7.5%) and mild bleeding (15.1%). On early postoperative follow-up, 47.1% recalled no impairment in quality of life, and 25%, 21.2 %, and 6.7% had mild, moderate and sever disturbance respectively. The median time to return to work or school was 10 days. At a median follow-up of 29 months (IQR 19-40), recurrence rate was 45.1% (51/113), and 38 (33.9%) of the patients underwent another surgical procedure Overweight, smoking, and family history were associated with higher recurrence rate. CONCLUSIONS: The trephines technique has a significant long-term recurrence rate. Short-term advantages include low morbidity, enhanced recovery, and minimal to mild postoperative impairment to quality of life. The trephine procedure may be justified as a first treatment of pilonidal disease.

Experienced surgeons versus novice surgery residents: Validating a novel knot tying simulator for vessel ligation.

BACKGROUND: Vessel ligation with a knot is one of the most fundamental tasks surgeons must master. We developed a simulator designed to enable novices to acquire and refine gentle knot tying capabilities. METHODS: A bench-top, knot-tying simulator with computer-acquired assessment was tested on expert surgeons and surgery residents at an academic medical center during the years 2016 to 2018. Each participant tied a total of 8 knots in different settings (superficial versus deep) and techniques (1-handed versus 2 hands). The simulator measured vertical forces and task completion time. RESULTS: Fifteen experienced surgeons and 30 surgery residents were recruited. The expert group exerted considerably less total force during placement of the knots than the novice residents (3.8 ± 2.0 vs 9.2 ± 6.1 N, respectively; P = .0005) and the peak force exerted upward was less in the expert group (1.31 ± 0.6 vs 1.75 ± 0.84 N; P = .02). The experts also completed the task in less time (10.9 ± 3.4 vs 18.3 ± 7.2 seconds; P = 0.001). CONCLUSION: The simulator can offer residency programs a low-cost, bench-top platform to train and assess objectively the knot-tying capabilities of surgery residents.

Feedback based simulator training reduces superfluous forces exerted by novice residents practicing knot tying for vessel ligation.

BACKGROUND: Technological advances have led to the development of state-of-the-art simulators for training surgeons; few train basic surgical skills, such as vessel ligation. METHODS: A novel low-cost bench-top simulator with auditory and visual feedback that measures forces exerted during knot tying was tested on 14 surgical residents. Pre- and post-training values for total force exerted during knot tying, maximum pulling and pushing forces and completion time were compared. RESULTS: Mean time to reach proficiency during training was 11:26 min, with a mean of 15 consecutive knots. Mean total applied force for each knot were 35% lower post-training than pre-training (7.5 vs. 11.54 N (N), respectively, p = 0.039). Mean upward peak force was significantly lower after, compared to before, training (1.29 vs. 2.12 N, respectively, p = 0.004). CONCLUSIONS: Simulator training with visual and auditory force feedback improves knot-tying skills of novice surgeons.

Genome-wide siRNA screen reveals a new cellular partner of NK cell receptor KIR2DL4: heparan sulfate directly modulates KIR2DL4-mediated responses.

KIR2DL4 (CD158d) is a distinct member of the killer cell Ig-like receptor (KIR) family in human NK cells that can induce cytokine production and cytolytic activity in resting NK cells. Soluble HLA-G, normally expressed only by fetal-derived trophoblast cells, was reported to be a ligand for KIR2DL4; however, KIR2DL4 expression is not restricted to the placenta and can be found in CD56(high) subset of peripheral blood NK cells. We demonstrated that KIR2DL4 can interact with alternative ligand(s), expressed by cells of epithelial or fibroblast origin. A genome-wide high-throughput siRNA screen revealed that KIR2DL4 recognition of cell-surface ligand(s) is directly regulated by heparan sulfate (HS) glucosamine 3-O-sulfotransferase 3B1 (HS3ST3B1). KIR2DL4 was found to directly interact with HS/heparin, and the D0 domain of KIR2DL4 was essential for this interaction. Accordingly, exogenous HS/heparin can regulate cytokine production by KIR2DL4-expressing NK cells and HEK293T cells (HEK293T-2DL4), and induces differential localization of KIR2DL4 to rab5(+) and rab7(+) endosomes, thus leading to downregulation of cytokine production and degradation of the receptor. Furthermore, we showed that intimate interaction of syndecan-4 (SDC4) HS proteoglycan (HSPG) and KIR2DL4 directly affects receptor endocytosis and membrane trafficking.