|Year : 2015 | Volume
| Issue : 2 | Page : 138-141
Congenital internal hernias: Rare cause of intestinal obstruction in newborns
Patricia Lange1, Dan Parrish2
1 Department of Surgery, Division of Pediatric Surgery, Virginia Commonwealth University, P.O Box 980015, Richmond, VA 23298-0015, USA
2 Department of Surgery, P.O. Box 980135, Virginia Commonwealth University, Richmond, VA 23298-0135, USA
|Date of Web Publication||6-Apr-2015|
Dr. Patricia Lange
Department of Surgery, Division of Pediatric Surgery, Virginia Commonwealth University, P.O. Box 980015, Richmond, VA 23298-0015
Source of Support: None, Conflict of Interest: None
Intestinal obstruction in newborns can be life threatening. Congenital internal hernias comprise a very rare cause of the blockage and are thought to arise from a defect in the formation of the mesentery of the small intestine. We describe two cases of neonatal internal hernias and review the current literature. Both infants had clinical signs of obstruction shortly after birth, but the cause of the obstruction was not found until surgical intervention took place. Intestinal necrosis due to segmental twisting of the intestine through a mesenteric defect was found requiring resection and temporary enterostomies. At outpatient follow-up, both children are doing well with normal intestinal function. Our two cases along with the current literature review, illustrate the rare nature of this condition, but one that should be considered in any neonate presenting with intestinal obstruction.
Keywords: Internal hernia, intestinal obstruction, mesenteric defect, segmental volvulus
|How to cite this article:|
Lange P, Parrish D. Congenital internal hernias: Rare cause of intestinal obstruction in newborns. J Clin Neonatol 2015;4:138-41
| Introduction|| |
Congenital internal hernias are rare in pediatric populations. Up to 35% of these are transmesenteric and thought to arise from a defect in the formation of the mesentery of the small intestine. , They are classified based on their location and can be either asymptomatic or cause bowel obstruction.  In neonatal congenital internal hernias, a segmental volvulus can form from the herniation of bowel, and if left untreated, results in necrosis and perforation. This is an especially serious concern in neonates as the mortality rate exceeds 50%.  We present two cases of neonatal transmesenteric congenital internal hernias and review of the literature.
| Case Reports|| |
Consultation was requested for a 3 day old, premature infant born at 26 weeks and weighing 670 g for abdominal distension. Abdominal plain films revealed a dilated loop of small bowel in left mid and lower abdomen with no distal gas [Figure 1]. The patient developed increasing abdominal distention and signs of a small bowel obstruction warranting surgical intervention [Figure 2].
|Figure 1: Abdominal X-ray shortly after birth to assess umbilical catheter placement. It demonstrates mildly dilated loops of bowel on the left side and mid abdomen with no distal gas|
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|Figure 2: (a and b) Abdominal X-rays, in 3 day old infant, with distended loops of bowel, concerning for obstruction (a) Lateral decubitus view (b) Supine view|
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At the time of exploration, a dilated and necrotic section of bowel was encountered near the terminal ileum caused by internal herniation through a mesenteric defect. A 4 cm portion of bowel was resected, and an end ileostomy and mucous fistula were created. Abdominal X-rays taken the following day demonstrated a relatively normal gas pattern [Figure 3].
|Figure 3: Abdominal X-ray, on postoperative day one, with no visualized loops of small bowel and more aerated lungs|
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He returned to the operating room 3 months later for ileostomy takedown and was ultimately discharged from the hospital on the day of life 137 on full enteral feeds.
A 9 h old term infant was evaluated by the pediatric surgical service due to abdominal distention and abdominal wall erythema. Abdominal X-rays [Figure 4] and ultrasound demonstrated a paucity of gas on the right side of the abdomen and dilated loops of the proximal small bowel in the left prompting urgent surgical exploration. Upon entering the abdomen, a segmental volvulus secondary to internal herniation through a mesenteric defect in the distal small bowel was noted. The necrotic region was excised with 91 cm of small bowel remaining and an ileostomy was created. 5 weeks after his initial operation, he returned to the operating room for ileostomy takedown after a barium enema showed no signs of distal obstruction [Figure 5]. He had no surgical complications and was discharged 15 days later.
|Figure 4: Abdominal X-ray with lack of air on the right side and dilated loops of bowel on the left side|
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|Figure 5: Barium enema demonstrating patency throughout the small and large intestines|
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Both patients are doing well on full feeds with normal bowel function at 22 and 12 months out, respectively.
| Discussion|| |
The first case of a mesenteric hernia was reported by Rokitansky in 1836, describing a postmortem examination of the cecum herniating through a defect close to the ileocolic angle.  The overall frequency of congenital intra-abdominal hernias and risk of herniation remains largely unknown. In 1977, Freund and Berlatzky estimated that 0.5-3% of intestinal obstructions are due to internal hernias, and in 1984 autopsy findings estimated that 30% of the intraabdominal hernias remain asymptomatic throughout a lifetime. , It has been estimated that congenital transmesenteric hernias constitute 5-10% of internal hernias. ,
Intra-abdominal hernias are categorized by the localization of the defect - Paraduodenal, pericecal, transmesenteric or transsigmoidal. In the neonatal and pediatric population, transmesenteric hernias are the most common location.  A 2011 retrospective chart review of 12 children with internal hernias noted that all five of the neonates had transmesenteric internal hernias present, four of which were congenital and the other acquired postoperatively. 
Mortality rates of up to 45% for patients with transmesenteric hernias has been reported.  and rates may increase well over 50% in patients who go untreated. ,
The etiology of mesenteric defects is also unclear and poorly understood. Hypotheses include regression of the dorsal mesentery, developmental enlargement of a hypovascular area, rapid lengthening of a segment of mesentery and compression of the mesentery by the colon during fetal midgut herniation. ,,,
Currently, the role of computed tomography (CT) scans in diagnosing internal hernias is not fully agreed upon; however, the use of ultrasound imaging may be helpful in ruling out other possible pathologies. ,,, Surgical exploration remains the mainstay of diagnosis and treatment and any delay can have significant ramifications as it may lead to bowel necrosis. Furthermore, transmesenteric hernias may carry a greater risk for segmental volvulus and bowel ischemia compared to other types of hernias. ,
Clinically, neonates tend to present with nonspecific signs of obstruction once they are started on full enteral feeds; however, in the both of our patients, the symptoms were present shortly after birth.  Given the downside to delay of surgical intervention and lack of specific tests, open exploration continues to be the only way to establish a definitive diagnosis of a transmesenteric hernia.
Given the relative rarity of congenital transmesenteric hernias in the newborn and neonatal population, we compiled the cases that have been reported in English-language literature. The search yielded six patients, four of which are from a retrospective imaging review by Tang et al. [Table 1]. ,,
|Table 1: Compilation of neonatal congenital transmesenteric hernias in literature (number 1 - 6); cases presented in this report (number 7 - 8)|
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The average age at diagnosis was 8.3 days with two patients being born premature. None of the cases reported were able to appreciate a hernia preoperatively. No deaths were reported in this case review but there is one case from Japan of a nonneonate (20 months old) dying as a result of a transmesenteric hernia. 
Our patients are unique because they both presented with obstructive symptoms at, or very near, the time of birth, one of whom was extremely premature. As such, necrotizing enterocolitis and inflammatory strictures were not considered as likely. The differential diagnosis with this presentation includes intestinal atresia, malrotation with volvulus, congenital adhesive bands (omphalomesenteric), inguinal hernias and obstructing masses.
| Conclusion|| |
Congenital mesenteric defects may be present and asymptomatic in a significant portion of the population. Internal hernias due to mesenteric defects may present in the first few hours of life as signs of intestinal obstruction. Left untreated, segmental twisting will lead to subsequent intestinal necrosis and carries a high mortality rate. Therefore, early suspicion and operative exploration in any neonate or infant with signs of intestinal obstruction is paramount.
| References|| |
Ghahremani GG. Abdominal and pelvic hernias. In: Gore RM, Levine MS, editors. Textbook of Gastrointestinal Radiology. 2 nd
ed. Philadelphia, PA: Saunders; 2000. p. 1993-2009.
Meyers MA. Dynamic Radiology of the Abdomen: Normal and Pathologic Anatomy. 4 th
ed. New York: Springer-Verlag; 1994.
Martin LC, Merkle EM, Thompson WM. Review of internal hernias: Radiographic and clinical findings. AJR Am J Roentgenol 2006;186:703-17.
Newsom BD, Kukora JS. Congenital and acquired internal hernias: Unusual causes of small bowel obstruction. Am J Surg 1986;152:279-85.
Gatewood J. Intra-peritoneal hernias through mesenteric defects. West J Surg 1934;42:191.
Freund H, Berlatzky Y. Small paraduodenal hernias. Arch Surg 1977;112:1180-3.
Ghahremani GG. Internal abdominal hernias. Surg Clin North Am 1984;64:393-406.
Blachar A, Federle MP. Internal hernia: An increasingly common cause of small bowel obstruction. Semin Ultrasound CT MR 2002;23:174-83.
Dowd MD, Barnett TM, Lelli J. Case 02-1993: A three-year-old boy with acute-onset abdominal pain. Pediatr Emerg Care 1993;9:174-8.
Tang V, Daneman A, Navarro OM, Miller SF, Gerstle JT. Internal hernias in children: Spectrum of clinical and imaging findings. Pediatr Radiol 2011;41:1559-68.
Janin Y, Stone AM, Wise L. Mesenteric hernia. Surg Gynecol Obstet 1980;150:747-54.
Sato T, Abe S, Tsuboi K, Iwata M, Tamura A, Tsuchihashi H, et al.
Sudden death of a child because of an intestinal obstruction caused by a large congenital mesenteric defect. Leg Med (Tokyo) 2012;14:157-9.
Page MP, Ricca RL, Resnick AS, Puder M, Fishman SJ. Newborn and toddler intestinal obstruction owing to congenital mesenteric defects. J Pediatr Surg 2008;43:755-8.
Federschmidt F. Embryonal origin of lacunae in mesenteric tissue; the pathologic changes resulting therefrom. Dtsch Ztschr F Chir 1920;158:205-11.
Macklin CC. Alveolar porre in the lungs of man and other mammals. Anat Rec Suppl 1935;61:33-9.
Menegaux G. Les hernies dites trans-mesocoliques; mesocolon transverse. J Chir 1934;43:321-5.
Blachar A, Federle MP, Dodson SF. Internal hernia: Clinical and imaging findings in 17 patients with emphasis on CT criteria. Radiology 2001;218:68-74.
Takeyama N, Gokan T, Ohgiya Y, Satoh S, Hashizume T, Hataya K, et al.
CT of internal hernias. Radiographics 2005;25:997-1015.
Hajivassiliou CA. Intestinal obstruction in neonatal/pediatric surgery. Semin Pediatr Surg 2003;12:241-53.
Merrot T, Anastasescu R, Pankevych T, Chaumoître K, Alessandrini P. Small bowel obstruction caused by congenital mesocolic hernia: Case report. J Pediatr Surg 2003;38:E11-2.
Okino Y, Kiyosue H, Mori H, Komatsu E, Matsumoto S, Yamada Y, et al.
Root of the small-bowel mesentery: Correlative anatomy and CT features of pathologic conditions. Radiographics 2001;21:1475-90.
Blachar A, Federle MP, Brancatelli G, Peterson MS, Oliver JH 3 rd
, Li W. Radiologist performance in the diagnosis of internal hernia by using specific CT findings with emphasis on transmesenteric hernia. Radiology 2001;221:422-8.
Malit M, Burjonrappa S. Congenital mesenteric defect: Description of a rare cause of distal intestinal obstruction in a neonate. Int J Surg Case Rep 2012;3:121-3.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]