Is the testis intraperitoneal?

Abstract

The relationship of the testis to the peritoneal cavity, and hence its position as an intraperitoneal or extraperitoneal organ, remains controversial. Adult anatomy texts favour an extraperitoneal position during and after testicular descent, whereas journal articles favour an intraperitoneal position. Interestingly, there is no similar debate around the position of the ovary despite the common origin of each as indifferent gonads. Through direct observation and the literature review, we aimed to determine whether the testis should be considered an intraperitoneal or an extraperitoneal organ. The anatomical and embryological literature relevant to human and animal models was reviewed. Direct dissections were made in rats (n=8) during foetal development, postnatally, and in mature animals, allowing comparison of foetus with adult and male with female. The position of the human testis was also recorded in various pathological states. Direct dissection in rats reveals an intraperitoneal testis on a mesorchium during both foetal and postnatal life. Intraperitoneal testes are demonstrated in humans in cases of gastroschisis (where the testis may protrude through the periumbilical defect with the bowel), testicular torsion (where the testis is mobile within the peritoneum), and bell clapper testis (where the testes are identifiable as intraperitoneal). We conclude that the foetal testis is an intraperitoneal organ. In the adult rat the testis remains intraperitoneal. The postnatal human testis is intraperitoneal. The adult human testis is intraperitoneal but may appear extraperitoneal. The apparent discrepancy between the adult testis being intraperitoneal or extraperitoneal is likely to result from differences in the relative size of the tunica vaginalis between infant boys and elderly men.

Unique Presentation of Intra-Abdominal Testis: Small Bowel Obstruction

“…It remains unclear whether the testis is an intra- or extraperitoneal organ. Although adult anatomy texts favor an extraperitoneal position, intraperitoneal testes have been observed in patients with gastroschisis, spigelian hernia, and testicular torsion [6]. …”

Effects of compression/stretching of the spermatic cord and blunt dissection on testicular growth and fertility

“…The spermatic cord, consisting of vas deferens and the spermatic vessels, was identified in the mesorchium, a thin and pellucid membrane that contains spermatic vessels and vas deferens, and 2 holes were bored through the lateral sides of the mesorchium to avoiding injury of anonymous vessels in the membrane, to pass a loop around the spermatic cord [5,6]. A vascular sling was inserted through one hole and passed around the cord and through the other hole, to form a loop around the cord.…”

The role of the gubernaculum in the descent and undescent of the testis

“…Conditions with lower abdominal pressure, such as gastroschisis, have a significant incidence of cryptorchidism. In this case, not only is abdominal pressure in the processus reduced, but also the gubernacular cord is often torn, enabling the testis to prolapse out of the defect along with the bowel [Pham et al 2005].…”