Although the treatment of classic malrotation has changed little in the last 80 years, advancements in medical care and the increasing availability of diagnostic techniques have raised new questions regarding the management of rotation abnormalities.
Beginning in the mid-1990s, a laparoscopic approach to the Ladd procedure has been advocated by some surgeons. This is most commonly reserved for malrotation not associated with midgut volvulus, as the bowel in patients with volvulus can be quite friable and subject to perforation with all but the most gentle manipulation, as well as the fact that surgery must be done as quickly as possible to maximize the chance of survival.
In infants, the most commonly described technique utilizes three 3.5-mm ports, with a fourth port added to help with bowel retraction and operative exposure. In older children, 5-mm ports may be used. The operation begins with the placement of an umbilical trocar and abdominal insufflation to a pressure of 8 to 12 mm Hg, followed by the placement of 2 additional trocars in the right and left mid to low abdomen (depending on the size of the infant). Careful exploration of the abdomen is then performed and the specific anatomy of the patient delineated. Of particular importance, the presence or absence of midgut volvulus should be noted. If there is no volvulus, the next step is determination of the length of the small bowel mesentery, that is, the distance between the DJJ and the cecum. If this distance is long (in our center defined as greater than half the diameter of the abdomen), as would be seen in both near-normal rotation and in nonrotation, the patient is not considered to be at risk for midgut volvulus, and a Ladd procedure is not necessary. In this scenario, obstructing bands around the duodenum should be identified and divided, and any internal hernias should be identified and repaired. If the base of the small bowel mesentery is short, the patient should be considered to be at risk for volvulus, and a full Ladd procedure should be done. The steps are the same as for the open procedure, and dissection can be done using hook electrocautery, sharp scissors, or scissors attached to cautery. In larger children, the harmonic scalpel may also be used. If an appendectomy is performed, it can be done extracorporeally through the umbilical port site or intraabdominally with an endoloop or stapler.
Advocates of a laparoscopic approach cite decreased postoperative pain and more rapid return of bowel function (and thus shorter hospital stay) as well as an obvious cosmetic advantage. Detractors suggest that intraoperative visualization of the mesenteric pedicle is inadequate, especially in the population most commonly affected by malrotation: infants less than 1 year of age. It has also been suggested that open correction of malrotation may be more effective in preventing recurrent volvulus by facilitating the formation of intraabdominal adhesions and that the laparoscopic approach may not achieve this ancillary benefit to the same extent. Advocates of the laparoscopic approach argue that prevention of recurrent volvulus is accomplished by adequate broadening of the mesenteric base rather than by adhesions, and that adhesion formation results in a long-term risk of intestinal obstruction requiring further surgical correction. To date, there have been no large-scale studies with enough longitudinal follow-up to demonstrate this theoretical benefit.
Atypical Radiological Findings
The group at the University of Arkansas attempted to define risk of malrotation, ischemic volvulus, and internal hernia in a group of consecutive patients undergoing operation for rotation abnormalities based on the positioning of the DJJ on initial UGI series. The rotation abnormality was described as “typical” if the DJJ was positioned to the right of the midline or if it was absent. Atypical variants of malrotation were classified as “high” if the DJJ was at or to the left of the midline but higher than the 12th thoracic vertebra and “low” if it was at or to the left of the midline below the 12th thoracic vertebra. Approximately 43% of presenting patients were classified as “typical,” 32% were “high” and the remaining 25% were “low.” All patients with “typical” and “low” rotation abnormalities on UGI were found to have a rotation abnormality intraoperatively, and 95% of patients with a “high” malformation on UGI were confirmed to have a rotation abnormality intraoperatively. At the time of operation, volvulus had occurred in 12 of 75 of “typical” patients versus 1 of 56 “high” and 1 of 45 “low” patients. Internal hernias were also more common in “typical” than “atypical” patients. Moreover, this group found that 11% to 13% of “atypical” patients had persistent postoperative symptoms compared to 0% of “typical” patients. Given the cited postoperative bowel obstruction rate following Ladd procedure (8%-12%) and the relatively high incidence of continued symptomatology, the authors advocated careful discussion in patients with “atypical” radiological findings. This is a group in which a laparoscopic approach might be particularly useful.
Asymptomatic Rotation Abnormalities
While there is general consensus that symptomatic malrotation should be addressed surgically, the role of prophylactic surgery in children with incidentally diagnosed, asymptomatic rotation abnormalities is less clear. Advocates of routine operative intervention cite reports of midgut volvulus secondary to malrotation throughout adult life and further argue that a careful history often elicits subtle symptoms of malrotation that may have been dismissed or attributed to other causes. However, population-based evidence suggests that the incidence of midgut volvulus secondary to malrotation decreases significantly after infancy and that many patients with rotation abnormalities remain asymptomatic throughout life. The only study to date that attempts to address this question used malrotation data from the Nationwide Inpatient Sample to derive a model to compare the quality-adjusted life expectancy with and without a Ladd procedure in asymptomatic patients. This group found that the greatest benefit of a Ladd procedure occurred in infants at 1 year of age and declined thereafter. By age 20, a Ladd procedure conferred more risk than nonoperative observation. These authors concluded that operative intervention should be offered to children, but not adults with asymptomatic malrotation.
Ultimately, the most important decision in an asymptomatic patient is whether there is a risk of midgut volvulus or not, that is, what is the width of the small bowel mesentery? Sometimes this can be well seen on contrast imaging, and a reasonable decision can be made regarding surgical intervention. However, contrast imaging has a clearly delineated false-positive and false-negative rate, and laparoscopy may be a safer and more definitive way of determining the need for a Ladd procedure. If at the time of laparoscopy the mesenteric base is found to be wide, the operation can be concluded, with minimal morbidity. If the mesenteric base is found to be narrow, a Ladd procedure can be done either laparoscopically or open, at the discretion of the surgeon.
Patients with heterotaxia syndromes (HS, defined as any arrangement of organs along the left–right body axis, which is neither situs solitus nor situs inversus) are known to have a high rate of rotation anomalies, which cover the entire spectrum from nonrotation to classic malrotation to near-normal rotation, as well as the more uncommon rotation abnormalities such as reverse rotation. The coexistence, in many cases, of congenital heart disease places these children at an increased risk of operative intervention, which has resulted in controversy around the role of generalized screening for rotation abnormalities in patients with heterotaxia, and the role of intervention in asymptomatic patients with documented rotation abnormalities. While several centers have found that the morbidity and mortality associated with a Ladd procedure in patients with HS is not increased over a control population, the procedure itself is associated with a 10% risk of postoperative bowel obstruction and overall childhood mortality in patients with HS is 23%, mainly due to cardiac disease. In our own study following 152 asymptomatic neonates with HS, only 4 developed gastrointestinal symptoms over a median follow-up of 18 months (range, 4-216), and only 1 of these 4 was found to have malrotation on UGI. Of the remaining asymptomatic patients, 43% died of cardiac disease and none developed intestinal symptoms or complications. We have therefore adopted a more conservative approach in which asymptomatic patients with HS are not screened for rotation abnormalities unless they develop symptoms. Those with documented rotation abnormalities and either mild symptoms or no symptoms are evaluated laparoscopically.