**3.2 Malrotation and midgut volvulus**

## *3.2.1 Embryology*

As described above, normal 270° rotation and fixation of the midgut fails to occur [4–7]. This lack of rotation positions the duodenum and small bowel to the right of the midline and the large bowel to the left. The cecum remains anterior to the duodenum and is tethered to the abdominal wall by lateral peritoneal attachments. These lateral peritoneal attachments, known as Ladd's bands, compress the duodenum, thereby causing obstruction and resultant bilious emesis. The root of the mesentery is narrowed and may potentially act as fulcrum around which the bowel can twist ("volvulize"), thereby kinking the SMA and causing ischemia (**Figure 5**).

## *3.2.2 Clinical presentation*

Acute malrotation with midgut volvulus presents with feeding intolerance and bilious emesis, usually around the first week of life. Abdominal rigidity, overlying erythema are signs of peritonitis and indicate ischemic bowel. Abdominal distention will not be present given the very proximal nature of pathology. As feeding intolerance and bilious emesis are symptoms of multiple pathologies, a high index of suspicion is required to make this diagnosis.

#### *3.2.3 Diagnosis*

An abdominal X-ray is typically first obtained, though rarely helpful in establishing the diagnosis. Any concern for malrotation mandates a prompt UGI. A normal study will reveal contrast exiting the pylorus, descending through the second portion of the duodenum and crossing the midline through the third portion of the duodenum into the small bowel. Thus, a normal "C-loop" will be visualized. An abnormal study will demonstrate contrast exiting the pylorus and descending straight down to the right of the midline into the small bowel.

#### *3.2.4 Surgical management*

Once the diagnosis of acute malrotation is made, the patient is taken emergently to the operating room for detorsion and evaluation of bowel viability. Fluid resuscitation, insertion of oro- or nasogastric tube for decompression and administration of intravenous antibiotics have ideally been implemented prior to surgical intervention. The bowel is eviscerated and detorsed in a counterclockwise direction, fanning out its mesentery. Ladd's bands are incised to release the obstruction. Any frankly necrotic appearing bowel is resected, while dusky bowel can be re-evaluated and usually salvaged in a second look operation 24–48 h later. Ends of healthy, viable bowel can be anastomosed, otherwise stomas are placed. A prophylactic appendectomy is performed to eliminate the possibility of appendicitis in the future. If a second look operation is required, the abdomen is left open and covered with a temporary sterile dressing; if not, it is closed.

**97**

*3.2.5 Outcomes*

**Figure 5.**

*3.3.1 Embryology*

**3.3 Meckel's diverticulum**

*3.3.2 Clinical presentation*

Without significant intestinal necrosis requiring resection, outcomes following correction of malrotation are quite favorable. Infants grow normally and do not have any major adverse sequelae. Rarely, adhesive small bowel obstruction may

This condition occurs as a result of the failure of the omphalomesenteric (vitel-

Meckel's diverticulum is the most common congenital GIT malformation and the most common cause of painless lower intestinal bleeding in children. It usually presents by the age of 2 years, but presentation can be delayed into the teenage

line) duct to completely involute between weeks 5–7 of gestation (**Figure 6**).

occur years later, however any operation carries this risk.

*Intestinal malrotation showing abnormal position of cecum and Ladd's bands*

*Congenital Anomalies of the Gastrointestinal Tract DOI: http://dx.doi.org/10.5772/intechopen.92588*

*Congenital Anomalies of the Gastrointestinal Tract DOI: http://dx.doi.org/10.5772/intechopen.92588*

#### **Figure 5.**

*Congenital Anomalies in Newborn Infants - Clinical and Etiopathological Perspectives*

cardiac defects.

*3.2.1 Embryology*

(**Figure 5**).

*3.2.3 Diagnosis*

*3.2.2 Clinical presentation*

*3.2.4 Surgical management*

of suspicion is required to make this diagnosis.

straight down to the right of the midline into the small bowel.

with a temporary sterile dressing; if not, it is closed.

**3.2 Malrotation and midgut volvulus**

syndrome, those with less than 40 cm, often require long term parenteral nutrition, which itself carries risks of sepsis and liver damage. Nonetheless, overall mortality is low and related to co-morbidities, such as low birth weight and/or

As described above, normal 270° rotation and fixation of the midgut fails to occur [4–7]. This lack of rotation positions the duodenum and small bowel to the right of the midline and the large bowel to the left. The cecum remains anterior to the duodenum and is tethered to the abdominal wall by lateral peritoneal attachments. These lateral peritoneal attachments, known as Ladd's bands, compress the duodenum, thereby causing obstruction and resultant bilious emesis. The root of the mesentery is narrowed and may potentially act as fulcrum around which the bowel can twist ("volvulize"), thereby kinking the SMA and causing ischemia

Acute malrotation with midgut volvulus presents with feeding intolerance and bilious emesis, usually around the first week of life. Abdominal rigidity, overlying erythema are signs of peritonitis and indicate ischemic bowel. Abdominal distention will not be present given the very proximal nature of pathology. As feeding intolerance and bilious emesis are symptoms of multiple pathologies, a high index

An abdominal X-ray is typically first obtained, though rarely helpful in establishing the diagnosis. Any concern for malrotation mandates a prompt UGI. A normal study will reveal contrast exiting the pylorus, descending through the second portion of the duodenum and crossing the midline through the third portion of the duodenum into the small bowel. Thus, a normal "C-loop" will be visualized. An abnormal study will demonstrate contrast exiting the pylorus and descending

Once the diagnosis of acute malrotation is made, the patient is taken emergently to the operating room for detorsion and evaluation of bowel viability. Fluid resuscitation, insertion of oro- or nasogastric tube for decompression and administration of intravenous antibiotics have ideally been implemented prior to surgical intervention. The bowel is eviscerated and detorsed in a counterclockwise direction, fanning out its mesentery. Ladd's bands are incised to release the obstruction. Any frankly necrotic appearing bowel is resected, while dusky bowel can be re-evaluated and usually salvaged in a second look operation 24–48 h later. Ends of healthy, viable bowel can be anastomosed, otherwise stomas are placed. A prophylactic appendectomy is performed to eliminate the possibility of appendicitis in the future. If a second look operation is required, the abdomen is left open and covered

**96**

*Intestinal malrotation showing abnormal position of cecum and Ladd's bands*

#### *3.2.5 Outcomes*

Without significant intestinal necrosis requiring resection, outcomes following correction of malrotation are quite favorable. Infants grow normally and do not have any major adverse sequelae. Rarely, adhesive small bowel obstruction may occur years later, however any operation carries this risk.

#### **3.3 Meckel's diverticulum**

#### *3.3.1 Embryology*

This condition occurs as a result of the failure of the omphalomesenteric (vitelline) duct to completely involute between weeks 5–7 of gestation (**Figure 6**).

#### *3.3.2 Clinical presentation*

Meckel's diverticulum is the most common congenital GIT malformation and the most common cause of painless lower intestinal bleeding in children. It usually presents by the age of 2 years, but presentation can be delayed into the teenage

years. There is a male predominance. The bleeding is typically brisk and bright red. Laboratory values will demonstrate anemia. A fibrous cord connecting the diverticulum to the abdominal wall may be present and can act as a point around which bowel can obstruct, twist or intussuscept. In such cases, the child will present with abdominal pain and distention, inability to pass flatus or move their bowels.
