Abdominal hernias can be a significant problem in patients treated with continuous peritoneal dialysis (PD) . A discussion of abdominal hernias in patients undergoing peritoneal dialysis will be presented in this topic review.
In the early 1980s, the incidence of abdominal hernia was approximately 10 to 15 percent per year. Historically, the incidence was lower with intermittent than with continuous ambulatory PD, with the former having an annual rate of less than 5 percent .
A subsequent advance, the utilization of a paramedian approach to PD catheter insertion, has significantly reduced the incidence of exit site and incision hernias [3,4]. Hernia rates are currently reported at a rate of 0.04 to 0.08 per patient per year [1,5,6].
RISK FACTORS FOR HERNIA FORMATION
Studies conflict regarding risk factors for hernia formation [4-7]. A large study conducted in the United States of 1864 peritoneal dialysis (PD) patients did not show an association between hernias and patient age, body surface area, PD modality, volume of dialysate time of largest dwell or type of catheter used. Cystic disease conferred a 2.5-fold increase in risk for anatomic complications; female gender conferred an 80 percent reduction in risk, and Kt/V ≥2.0 conferred a 52 percent reduction in risk (p <0.05) for hernia . From a pathophysiologic standpoint, these risk factors reflect anatomic, hydrostatic, or metabolic factors that can influence hernia formation.
Anatomic sites — The sites of anatomic weakness that predispose to hernia formation include the inguinal canals, umbilicus, linea alba, patent processus vaginalis, exit site, and site of a prior surgical incision. As an example, the testes descend into the scrotum via the processus vaginalis, which should then become obliterated. However, a patent processus vaginalis has been found in 90 percent of infants at birth and, at autopsy, in up to 37 percent of adults without hernias. Leakage of peritoneal fluid into a patent processus vaginalis can result in the formation of an indirect inguinal hernia.