Surgical instruments and catheter damage during ventriculoperitoneal shunt assembly

OBJECTIVE Current surgical techniques use common surgical instruments for sterile shunt assembly. This study investigated the impact of using these techniques and surgical instruments on the mechanical integrity of the ventriculoperitoneal shunt system, specifically shunt catheters. METHODS The authors conducted failure testing on 85 rifampin-coated catheters and 85 barium-impregnated catheters using 5 different surgical instruments and 2 different surgical techniques. In technique A, the distal end of the catheter was pushed onto the shunt valve inlet connector with the surgical instrument. In technique B, the catheter was pulled over the inlet connector. One hundred sixty catheters underwent 10-repetition-maximum testing, in which the catheter either failed before completion of 10 consecutive assembly/disassembly repetitions or the catheter completed 10 consecutive repetitions. The authors also conducted 100-repetition-maximum tests on 5 barium-impregnated and 5 rifampin-coated catheters using technique A. RESULTS Catheter failure rates were significantly different among the different instruments used in assembly (p <= 0.001). Post hoc analysis showed that using mosquito forceps with shods resulted in a significantly lower catheter failure rate than the other instruments (p < 0.0005). The catheter failure rate of technique A was significantly lower than that of technique B (5% vs 81%, p < 0.001). There was no statistical difference between the failure rates of the barium and rifampin catheters (42% vs 44%, p = 0.9), but the barium catheters outperformed the rifampin catheters in the 100-repetition-maximum trials (p = 0.02). Instrument type (p = 0.0232) and catheter type (p = 0.0096) were both significant factors in determining the number of assembly/disassembly repetitions needed to cause catheter failure. It took an average of 2.79 repetitions of assembly/disassembly to cause catheter failure. DeBakey forceps had significantly lower mean repetitions to failure (mean 1.38) than the Gerald forceps without teeth (mean 2.73, p = 0.05) and bayonet (mean 3.25, p = 0.02). CONCLUSIONS This study was the first of its kind to analyze how physical manipulation affects the mechanical integrity of ventriculoperitoneal shunt components. The authors demonstrated a significantly lower shunt catheter failure rate when mosquito forceps with shods and technique A were used in assembly. Moreover, the authors established that use of DeBakey forceps resulted in failure with fewer assembly/disassembly repetitions than use of the Gerald and bayonet forceps, suggesting that DeBakey forceps are the most damaging instrument.