Palmar Creases and Their Implication on Carpal Tunnel Surgery.

BACKGROUND: A thorough knowledge of normal and variant anatomy of the wrist and hand is fundamental to avoiding complications during carpal tunnel release. The purpose of this study was to document variations of the surface anatomy of the hand to identify a safe zone in which the initial carpal tunnel incision could be placed. The safe zone was identified as the distance between the radial side of hook of hamate and the ulnar edge of the origin of the motor branch of the median nerve (MBMN). METHODS: Kaplan's cardinal line and other superficial markers were used to estimate the size of the safe zone, in accordance to prior published anatomical studies. The presence of a longitudinal palmar crease (thenar, median, or ulnar creases) within the safe zone was recorded. RESULTS: Of the 150 participants (75 male, 75 female) examined, the average safe zone widths were 10.85 (right) and 10.28 (left) mm. In all the hands examined, 86.33% of the safe zones (259 of 300) contained a longitudinal palmar crease. In the White population (n = 50), the average safe zone widths were 11.49 (right) and 10.01 (left) mm; in the African American population (n = 50), the average safe zone widths were 12.27 (right) and 12.01 (left) mm; and in the Asian population (n = 50), the average safe zone widths were 8.79 (right) and 8.82 (left) mm. On overage, males had a larger safe zone width than females by 4.55 mm. CONCLUSIONS: Although there seems to be variability between race and sex with regard to safe zone width, finding 86.33% of longitudinal palmar creases within the safe zone suggests that, for most patients, the initial carpal tunnel surgery incision may be hidden within the palmar crease while minimizing the risk of motor branch of the median nerve injury. Overall, the safe zone width is on average up to 10.5 mm measured from the hook of the hamate along Kaplan's cardinal line.

Lower Platelet Count Following Rabbit Antithymocyte Globulin Induction Is Associated With Less Acute Cellular Rejection in Heart Transplant Recipients.

BACKGROUND: Unlike lymphodepletion, a decrease in platelet count following induction immunosuppressive therapy with polyclonal rabbit antithymocyte globulin (rATG) is deemed as an adverse event. However, this phenomenon may represent a particular rATG antirejection mechanism. METHODS: This retrospective single-center study included 156 patients who received a heart transplant (HTx) between 2010 and 2018. All patients received rATG induction therapy for 5 days. Absolute lymphocyte count (ALC) and platelet counts were assessed on days 0, 7, and 14 following HTx. The primary outcome of the study was the first occurrence of acute cellular rejection (ACR) defined as grade ≥ 1B within 24 months after HTx. RESULTS: Both ALC and platelet counts decreased rapidly after induction. During the 24-month follow-up period, 17% of patients had ACR. Patients with ACR had significantly higher platelet count on day 7 (145 vs 104, P < .001) and higher ALC on day 14 (162 vs 130, P = .035) than those without rejection. Patients in the highest platelet count quartile showed more ACR (50% in quartile 4 vs 0% in quartile 1, P = .006) as well as a higher cumulative total rejection score. Univariate analysis showed that ACR was associated with platelet count on day 7, recipient age, and pretransplant cytomegalovirus IgG serology. In multivariable regression analysis, platelet count on day 7 was the most accurate predictor of ACR. CONCLUSIONS: Lower platelet count after induction with rATG is associated with less ACR. This suggests platelet involvement in antirejection mechanisms of rATG and a possible rationale for targeting platelets in future immunosuppressive strategies.