The Impact of Needle Geometry on Tissue Damage and Anastomotic Leakage: A Combined Analysis of Human Skin and Porcine Cardiovascular Models

Surgical needles have evolved to optimize tissue approximation while minimizing tissue damage. Needle point geometry is a critical operative factor that impacts surgical dexterity. This study aims to compare the effects of taper point (TP) and reverse cutting (RC) needles on tissue damage and anastomotic bleeding risk across different tissue types and needle diameters. Two experimental models were employed. The Tissue Damage Model pierced 10 abdominal and 10 cheek skin samples using TP and RC needles. Histologic impact on skin layers was analyzed. The Anastomosis Leakage Model measured fluid leakage after 30 porcine aortas were punctured by TP and RC needles of varying diameters in an ex vivo pulsatile flow system. Both experiments ensured controlled variables and consistent methodologies. In the Tissue Damage Model, RC needles caused twice as much dermal disruption in both abdominal and cheek skin as TP needles (p < 0.01). Abdominal skin exhibited twice the histological damage compared to facial skin, irrespective of needle geometry (p < 0.05). In the Anastomosis Leakage Model, RC needles caused 5.6-, 4.0-, and 8.7-fold more leakage than TP needles at small, medium, and large needle diameters, respectively (p < 0.002). Leakage from RC needles increased with needle diameter (p < 0.001). TP needles did not exhibit this effect. RC needles caused significantly more dermal disruption compared to TP needles. Greater tissue damage was observed in abdominal skin than in facial skin. Additionally, RC needles led to progressively higher fluid leakage as needle diameter increased, while TP needles did not.