PubMed1993
Internal abdominal hernias develop when one or more viscera extrude through an intraperitoneal orifice but remain within the peritoneal cavity. The orific may be normal (Winslow's foramen) or paranormal (peritoneal fossae: paraduodenal, ileocecal, inter- and mesosigmoidal, paracolic, supravesical, of the large ligament of uterus). All these hernias possess a sac and are true hernias. The orifice may also be abnormal: pathologic origin if formed in a mesentery or an omentum (trans-mesenteric, trans-mesocoloic, trans-omental, by colo-omental disinsertion) or in the form of an anomalous orific if it occurs in a congenital anomaly of a ligament (falciform ligament of liver) or a mesentery (mesentery of Meckel's diverticulum): all these hernias lack a sac and are "internal prolapses or procidentia". Of the 14 cases presently reported, 6 were hernias through a paranormal orifice: 2 left and 2 right paraduodenal, 1 intra-mesosigmoidal and 1 retrocecal; 6 were hernias through a pathologic orifice: 2 trans-mesenteric, 1 in the posterior cavity through a colo-omental dissinsertion hole and 3 trans-omental, and 2 were hernias through an anomalous orifice from absence of the falciform ligament of liver. Incidence of these hernias reported in the literature is between 0.2 and 0.9% of autopsies and 0.2 and 2% of parietal hernias, findings in our series being 0.098% (14 of 14,199 cases) of laparotomies and 0.32% (14 of 4,374 cases) of parietal hernias. Of 1,871 cases described in the occidental or near occidental literature (in French, English, Italian or German), 160 (8.55%) were hernias through Winslow's foramen, 1035 (55.31%) through a para-normal orifice and 676 (36.1) through an abnormal orifice (pathologic and anomalous). The sex ratio showed a male prevalence (3:2), age distribution demonstrating the onset of internal hernias at all ages with a preference for the 5th decade and a mean age of 46 years. Symptomatology was totally non specific, subacute to acute occlusive symptoms or even signs of already installed necrotizing-peritonitis being detected in 80 to 90% of cases. In 10 to 15% of patients the hernia was an unexpected finding during laparotomy for another affection, an almost typical feature of the largest para-normal hernias, the paraduodenal hernias. Preoperative diagnosis is practically impossible, and in many cases cannot be made because of time restriction, but it is sometimes possible with the largest hernias after a longer sub-occlusive period by radiologic, arteriographic and scan imaging. However, the primary task of the surgeon is not so much to establish the diagnosis as to assess the need for urgent operation. Hernias provoking large displacements of viscera can even make intraoperative diagnosis difficult with subsequent errors, and surgeons must recognize all possible types of these hernias, especially those passing through a para-normal orifice, and must be able to pinpoint the fixed guiding points. They must also work in as large an operative field as possible and should therefore always start by a median infra-supra-umbilical laparotomy to allow its maximum extension. Reduction of herniated viscera can be simple, by gentle traction, or difficult requiring dilatation of the hernial orifice and/or opening of the sac.(ABSTRACT TRUNCATED AT 400 WORDS)