The spiral loop of the ascending colon (SLAC) in cattle has the form of a flattened disk consisting of two centripetal coils, a central loop and two centrifugal coils. It is attached to the great mesentery and it is located, with its longitudinal major axis, in the middle of the mass of the jejunum. In the last few years during autopsies or surgery to resolve pathologies such as volvulus, intussusception, and intestinal torsion, the frequent occurrence of abnormalities of location of the spiral loops (with or without detachment from the mesentery) was evidenced. So much so as to advance the hypothesis that these abnormalities might facilitate the above mentioned pathologies (Rademacher and Gentile, 2008). Moreover, a research on slaughtered calves showed a prevalence of SLAC abnormalities in 42.4% of the animals (472/1,113) (Gentile et al.; 2013). The deviations range from a simple reduction of the adherence to the mesentery (“conical relaxation”, with spiral coils loosely attached to the mesentery. 381/1,113 = 34.2% in the above mentioned slaughtered calves) to a situation of a partial detachment (“partial dystopia”, with distancing of only some spiral loops form the mesentery. 68/1,113 = 6.1%, see above). The worst case is the complete dislocation of all the spiral loops from the mesentery disk (“ectopia”, with detachment and total movement of the entire elliptic disk form its central mesentery position. 23/1,113 = 2.1%, see above). Aim of the present study was to verify whether abnormalities of location of the SLAC can be found also in the prenatal life. A macroscopic examination of the SLAC of 58 Holstein bovine fetuses was carried out. Fetuses size ranged from 14 cm to 80 cm in crown-rump length (CRL). All together 23 out of 58 fetuses showed a conformation of the SLAC different from what expected on the base of anatomical texts. In particular, 10/58 (17.2%) had a conical relaxation, 5/58 (8.6%) a partial dystopia and 2/58 (3.4%) a complete ectopia. Furthermore, SLAC of 6/58 fetuses (10.3%) , although having a correct adhesion to the great mesentery, showed abnormal spiraling. Finally, in 16/58 fetuses (27.6%) the spiral loops, instead of having two centripetal coils and two centrifugal coils, as normally described in veterinary anatomy texts, demonstrated just one and a half centripetal coils and one and a half centrifugal coils. This study supports the hypothesis that the abnormalities encountered previously in adult animals are, for the majority, of a congenital nature. The high prevalence of a conformation of the SLAC different from what described in anatomy texts , at least for the lightest deviations, indicates the need of reconsidering the true normal anatomical condition of the SLAC.
Macroscopic anatomical study of the spiral loop of the ascending colon in cattle fetuses
GRANDIS, ANNAMARIA;CANOVA, MARCO;BOLCATO M;PISONI, LUCIANO;GENTILE, ARCANGELO
2013
Abstract
The spiral loop of the ascending colon (SLAC) in cattle has the form of a flattened disk consisting of two centripetal coils, a central loop and two centrifugal coils. It is attached to the great mesentery and it is located, with its longitudinal major axis, in the middle of the mass of the jejunum. In the last few years during autopsies or surgery to resolve pathologies such as volvulus, intussusception, and intestinal torsion, the frequent occurrence of abnormalities of location of the spiral loops (with or without detachment from the mesentery) was evidenced. So much so as to advance the hypothesis that these abnormalities might facilitate the above mentioned pathologies (Rademacher and Gentile, 2008). Moreover, a research on slaughtered calves showed a prevalence of SLAC abnormalities in 42.4% of the animals (472/1,113) (Gentile et al.; 2013). The deviations range from a simple reduction of the adherence to the mesentery (“conical relaxation”, with spiral coils loosely attached to the mesentery. 381/1,113 = 34.2% in the above mentioned slaughtered calves) to a situation of a partial detachment (“partial dystopia”, with distancing of only some spiral loops form the mesentery. 68/1,113 = 6.1%, see above). The worst case is the complete dislocation of all the spiral loops from the mesentery disk (“ectopia”, with detachment and total movement of the entire elliptic disk form its central mesentery position. 23/1,113 = 2.1%, see above). Aim of the present study was to verify whether abnormalities of location of the SLAC can be found also in the prenatal life. A macroscopic examination of the SLAC of 58 Holstein bovine fetuses was carried out. Fetuses size ranged from 14 cm to 80 cm in crown-rump length (CRL). All together 23 out of 58 fetuses showed a conformation of the SLAC different from what expected on the base of anatomical texts. In particular, 10/58 (17.2%) had a conical relaxation, 5/58 (8.6%) a partial dystopia and 2/58 (3.4%) a complete ectopia. Furthermore, SLAC of 6/58 fetuses (10.3%) , although having a correct adhesion to the great mesentery, showed abnormal spiraling. Finally, in 16/58 fetuses (27.6%) the spiral loops, instead of having two centripetal coils and two centrifugal coils, as normally described in veterinary anatomy texts, demonstrated just one and a half centripetal coils and one and a half centrifugal coils. This study supports the hypothesis that the abnormalities encountered previously in adult animals are, for the majority, of a congenital nature. The high prevalence of a conformation of the SLAC different from what described in anatomy texts , at least for the lightest deviations, indicates the need of reconsidering the true normal anatomical condition of the SLAC.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
