what is malrotation?
Malrotation is a spectrum of congenital abnormalities of incomplete rotation and fixation of the intestinal tract
during fetal development. Its any deviation from the normal 270° counterclockwise rotation and fixation of the midgut around the superior mesenteric artery (SMA) during embryonic development. Can have catastrophic consequences when midgut volvulus occurs.
It involves the duodenojejunal junction (DJJ), cecum, and mesenteric attachments.
Incidence : 1/6000 live births
where does the duodenojejunal junction normally lie?
Duodenojejunal Junction (DJJ) normally lies to the left of the midline at the level of L2, anchored by the ligament of Treitz.
what is the mesentery?
The mesentery is a double fold of peritoneum that attaches the intestines to the posterior abdominal whall, supporting and anchoring them while allowing for blood vessels, nerves, and lymphatics to pass through to supply the organs. Its attachment, or root, is fan-shaped and extends obliquely from the duodenojejunal flexure (where the duodenum meets the jejunum) to the sacroiliac joint on the right side of the abdomen.
what is the SMA? describe its main branches
The superior mesenteric artery (SMA) is a major artery of the abdomen. It arises from the abdominal aorta, and supplies arterial blood to the organs of the midgut – which spans from the major duodenal papilla (of the duodenum) to the proximal 2/3 of the transverse colon.
The superior mesenteric artery is the second of the three major anterior branches of the abdominal aorta (the other two are the coeliac trunk and inferior mesenteric artery).
The superior mesenteric artery gives rise to various branches :
Inferior Pancreaticoduodenal Artery
It forms anterior and posterior vessels, which anastomose with branches of the superior pancreaticoduodenal artery (derived from the coeliac trunk). This network supplies the inferior region of the head of the pancreas, the uncinate process, and the duodenum.
Jejunal and Ileal Arteries
The arteries pass between the layers of the mesentery and form anastomotic arcades – from which smaller, straight arteries (known as the “vasa recta”) arise to supply the organs (fig 2). The jejunal blood supply is characterised by a smaller number of arterial arcades, but longer vasa recta. In contrast, the ileal blood supply is marked by more arterial arcades with shorter vasa recta.
Middle and Right Colic Arteries
Arise from the right side of the superior mesenteric artery to supply the colon:
Middle colic artery – supplies the transverse colon.
Right colic artery – supplies the ascending colon.
Ileocolic Artery
It passes inferiorly and to the right, giving rise to branches to the ascending colon, appendix, cecum, and ileum. In cases of appendectomy, the appendicular artery is ligated.
discuss the etiology and RF conditions associated with malrotation
Malrotation occurs due to interruption, incomplete rotation, or abnormal fixation during embryonic midgut development. Most cases are sporadic, but some are associated with (seen in 30%-60%). These anomalies frequently coexist with malrotation because they arise during overlapping periods of embryonic development, share common molecular signaling pathways (especially those governing left-right patterning and neural crest migration), or are part of syndromic constellations involving multiple organ systems:
1.Congenital heart defects and malrotation often coexist because they share early embryologic timing and laterality signaling defects. Both the heart tube looping and gut rotation occur around weeks 4–8. Examples:
* AV canal defects
* Transposition of great arteries
* Total anomalous pulmonary venous return
2.Duodenal atresia and biliary atresia : These arise from errors in foregut and midgut development that occur concurrently with intestinal rotation. Duodenal atresia results from failure of recanalization (weeks 8–10). Abnormal duodenal development can distort or anchor the duodenum, impeding normal midgut rotation and fixation.
3.Intussusception: Waugh’s syndrome is the **coexistence of ileocolic intussusception with intestinal malrotation. Malrotation predisposes to intussusception because Abnormally mobile cecum and mesentery increase the chance of telescoping of ileum into colon. Ladd’s bands or abnormal fixation points may also act as pathological lead points.
4.Dysmotility (e.g., intestinal neuronal dysplasia) and pseudo-obstruction syndromes: Neural crest cells colonize the gut concurrently with gut rotation. If migration is abnormal, both enteric nervous system formation and rotational development can be affected. In dysmotility syndromes: Malrotation is often a secondary association — abnormal fixation and length of mesentery can further impair peristalsis.
5.Duodenal atresia / stenosis / web: All are forms of duodenal obstruction caused by incomplete recanalization or mucosal diaphragm formation. These often coexist with malrotation because: They occur during the same developmental window (weeks 7–10). Structural distortion of the duodenum may prevent normal positioning of the duodenojejunal flexure.
6.Choanal atresia is not directly causative, but it often appears in syndromic contexts (e.g., CHARGE syndrome) where multiple embryonic structures develop abnormally together. The association is thus syndromic, not causa
describe the anomalies of rotation in malrotation
1 Nonrotation
Nonrotation may occur when the midgut returns to the abdominal cavity en masse without rotating. Only the first 90° occurs. The first and second parts of the duodenum are then situated normally, but the third and fourth parts descend vertically downward along the right side of the superior mesenteric artery. The small bowel lies on the right, and the colon is doubled on itself to the left of midline. Small bowel on right, colon on left. Usually asymptomatic but risk of volvulus. Ligament of Treitz fails to reach its normal position is right upper quadrant.
Midgut mesentry is narrow and highly mobile. May cause Duodenal obstruction abnormal peritoneal bands or Acute midgut volvulus.
2 Reversed Rotation
In reversed rotation, the cecum and colon are positioned posterior to the superior mesenteric vessels, and the
duodenum crosses anterior to it. Midgut rotates clockwise.
3 Malrotation
Malrotation is a spectrum of abnormalities that occurs when the normal process of rotation is arrested at various stages. Most frequently, the duodenojejunal flexure is located inferiorly and to the right of the midline. In addition, the cecum has failed to reach its normal position in the right iliac fossa and lies in a subhepatic or central position. Caecum in the epigastrium overlying 3rd part of duodenum. Most common form of surgically treated malrolation. narrow mesentery, high risk of volvulus.
describe the anomalies of migration in malrotation
1 Omphalocele
Return of the midgut from the yolk sac back into the abdominal cavity is usually completed by week 12 of intrauterine life. This enables the anterior abdominal wall mesodermal folds to meet at the central umbilical ring, thereby closing the anterior abdominal wall. When the return of the midgut is delayed or arrested, the anterior abdominal wall folds fail to meet, and an omphalocele in the central umbilical area of the abdomen is the result.
2 Congenital Diaphragmatic Hernia
When the pleuroperitoneal membrane which divides the coelomic cavity into peritoneal and pleural compartments fails to close before the return of the midgut into the abdominal cavity, part of the returning midgut loop may herniate into the pleural cavity. This occurs usually in the posterolateral position on the left side.
3 Subhepatic Appendix
With completion of the 270° rotation of the ileocecal limb of the midgut loop, the cecum is brought to the right upper quadrant of the abdomen. The cecum with the attached appendix then further descends down to the right lower quadrant position in the right iliac fossa and becomes fixed to the posterior abdominal wall. The cecum and appendix may fail to migrate and remain in that subhepatic position. This condition may cause a serious diagnostic dilemma in acute appendicitis.
describe the anomalies of fixation in malrotation
1 Volvulus Neonatorum
A normal fixation of the midgut loop results in a broad diagonal attachment of the loop to the posterior abdominal wall, extending from the ligament of Treitz to the ileocecal junction. With malfixation, the distance between these two points of attachment may become shortened, leaving the midgut loop hanging on a narrow and unstable pedicle that easily predisposes to twisting (volvulus) and strangulation.
2 Ladd’s Bands
When the cecum has failed to descend from the right upper quadrant to the right iliac fossa, anomalous fixation may occur, whereby dense fibrous bands (Ladd’s bands) extend from the cecum and right colon across the duodenum to the retroperitoneum of the right upper quadrant. These bands may cause duodenal obstruction via extrinsic compression; however, the obstruction of the duodenum is most commonly caused by torsion at the base of the midgut mesentery. Bands may also form between the colon and the duodenum, drawing them closer together and predisposing the midgut toward volvulus.
3 Mobile Cecum
Failure of fixation of the cecum to the posterior abdominal wall results in a floating cecum that may predispose to cecal volvulus.
4 Internal Hernias
Failure of fixation of the mesentery of the duodenum, right colon, or left colon may result in the formation of potential spaces for internal or mesocolic hernias. Internal hernias are associated with partial bowel obstructions, as there may be recurrent entrapment of bowel, which may eventually lead to obstruction and strangulation
outline the stringers classification of malrotation
Stringers classification categorizes malrotation into three types based on the degree of embryological rotation
I – Non rotation of colon and duodenum
IIA – Pure duodenal nonrotation
IIB- Reversed rotation of duodenum and colon
IIC – Reversed rotation of duodenum only
IIIA – Nonrotation of colon
IIIB- Incomplete fixation of hepatic flexure
IIIC- Incomplete attachment of cecum and mesocecum
Pathophysiology of malrotation
Malrotation results from failure of the midgut to complete its normal 270° anticlockwise rotation and fixation around the SMA during embryogenesis. This leads to abnormal positioning of the duodenojejunal junction (DJJ) and cecum, which remain abnormally close, producing a narrow mesenteric base. As a result, the entire midgut is suspended on a short, unstable vascular pedicle formed by the SMA and SMV, making it highly prone to twisting. The midgut typically rotates clockwise around the SMA axis, causing midgut volvulus. This rapidly compresses the SMA/SMV, leading to mesenteric ischemia, bowel congestion, and infarction, which can progress to necrosis within hours. The vascular compromise explains symptoms of sudden irritability, severe abdominal pain, abdominal distension, and signs of shock or sepsis in advanced cases. Additionally, duodenal obstruction produces early bilious vomiting, a hallmark clinical presentation. Ladd’s bands, abnormal peritoneal fibrous bands that extend from the abnormally positioned cecum to the posterior abdominal wall and cross over the duodenum, can also cause extrinsic duodenal compression, leading to intermittent or persistent obstructive symptoms (bilious emesis, feeding intolerance, abdominal distension) even in the absence of volvulus. If untreated, impaired intestinal perfusion leads to bowel necrosis, presenting with bloody stools, peritonitis, lethargy, metabolic acidosis, and cardiovascular collapse.
neonatal CF of malrotation
Neonates (Most common presentation):
Acute Midgut Volvulus – 75% present during First month of life
= sudden Recurrent episodes of subacute obstruction with intermittent bilious vomiting (hallmark sign). The point of
obstruction is typically beyond the ampulla of Vater, as demonstrated by the bilious emesis.
= Strangulating intestinal obstruction as a consequence of midgut volvulus. The infant presents with bile-stained
vomiting which may contain altered blood, may have abdominal distension and tenderness. The inconsolable infant may rapidly deteriorate as metabolic acidosis quickly advances to hypovolemic shock. As vascular compromise progresses, intraluminal bleeding may occur and blood is often passed per rectum (hematochezia).
As the strangulation progresses to gangrene, perforation, and peritonitis, edema and erythema of the anterior abdominal wall and the passage of dark blood per rectum (melena) becomes evident sign of mucosal ischemia.
older age CF of malrotation
Infants and older children:
Chronic Midgut volvulus - children older than 2 years
= Intermittent or cyclical vomiting which often contains bile.
= Failure to thrive.
= Intermittent severe abdominal colicky pain.
= Anorexia as a result of pain associated with eating.
= Malabsorption and/or diarrhea.
Rare - obstructive jaundice, chylous ascites and superior mesenteric vein thrombosis
list the diagnostic modalities of malrotation
Plain abdominal X-ray:
Upper GI contrast study (gold standard):
Ultrasound:
CT abdomen:
features of plain abd x-ray in malrotation
Patients should have two views of the abdomen: an anteroposterior supine view and either an anteroposterior upright view or a cross-table lateral view. Rarely do the radiographs suggest the diagnosis of malrotation. Instead, they help to exclude other etiologies for the patient’s symptoms and serve to guide further imaging.
Findings suggestive of an abnormal location of bowel include the following:
(a) Malposition of the bowel (“small bowel” to the right and “colon” to the left)
(b) Lack of distal bowel gas – a “gasless” abdomen or a “double bubble” appearance. A disproportionate dilatation of the duodenum with a “double bubble”—this may be seen with severe duodenal obstruction due to volvulus or bands
(c) “Whirled” appearance of mid-abdominal bowel
(d) Thick-walled, tubular loops with thickened folds or thumbprinting (suggesting chronic volvulus)
Features of complications
- Air fluids levels
- Pneumoperitoneum
features of upper GI contrast study in malrotation
It is usually performed with barium, except in cases of a very sick infant or child in whom the presence of infarcted bowel or perforation is possible, in which case water-soluble contrast is used.
The duodenum should normally be seen traveling across the spine to the left but shows the abnormal configuration of the duodenum, the duodenojejunal junction to the right of the midline, and the small bowel located on the right side of the abdomen. >ligament of Treitz not to the left of the midline or at the level of the gastric antrum
the “coil spring,” “corkscrew,” or “beak” appearance of the obstructed proximal jejunum. Where volvulus has occurred, the duodenum and upper jejunum show a ‘twisted ribbon’ or ‘corkscrew’ appearance.
The barium enema will show the cecum and appendix in an abnormal position, usually in the right hypochondrium or midabdomen
features of abd CT scan in malrotation
Anatomic location of small bowel on right and colon on left
Relationship of the superior mesenteric vessels – “vertically placed or inverted sides”
Aplasia of the uncinate process
Other associated anomalies
features of U/S in malrotation
Ultrasound can be used to evaluate other abdominal abnormalities and may be used to visualize the position of the mesenteric vessels. Normally, the superior mesenteric vein is to the right of the artery. In malrotation, the vein is frequently on the left, or it may rotate completely around the artery. * Inversion of SMA/SMV relationship (SMV to left of SMA).
The “whirlpool sign” on color Doppler ultrasonography which is created when the SMV and mesentery wrap around the SMA and may suggest midgut volvulus.
preop management of malrotation
Patients presenting with acute strangulating obstruction as a result of midgut volvulus require a brief period (not more than 2-3 hours) of intensive resuscitation in preparation for surgery. An i.v. infusion of crystalloids or 5% human albumin is given at 20 mL/kg administered as rapidly as possible, repeated as required, followed by 0.45% saline in 5-10% dextrose at 10 mL/kg per hour until induction of anesthesia.
NPO
nasogastric decompression.
* Broad-spectrum IV antibiotics given parenterally
Taken to the operating room for immediate exploration if volvulus is suspected — do not delay for imaging if signs of shock or peritonitis.
A specimen of blood is taken for crossmatch, hematology and serum electrolyte estimation. Blood for transfusion must be available at the commencement of the laparotomy.
describe Laddd’s open procedure for tx of malrotation
Ladd’s Procedure (open)
1.Exploratory laparotomy into abd cavity and evisceration
Perform a right upper abd transverse muscle-cutting incision. Deliver the bowel into the wound and inspect for volvulus, ischemia, or free fluid. A small volume of yellowish, free-peritoneal fluid is present in any early intestinal obstruction, but blood-stained fluid is indicative of intestinal necrosis. If volvulus is present, proceed immediately to the next step.
2. Untwist the volvulus
Most volvuli are clockwise — untwist them counterclockwise through 180° turns until free. Assess bowel viability:
* Moderately ischemic bowel appears Dusky/congested bowel usually recovers after detorsion and rapidly resumes a normal pinkish color.
* Questionable segments should be covered with moist swabs for ~10 min and reassessed.
* Necrotic bowel may be extremely friable and may disintegrate on handling and must be resected, with possible tying off of ends/stoma formation and second-look laparotomy in 24-48 hours when a clearer line of demarcation will have established.
3. Divide Ladd’s cecal bands
Ladd’s bands: peritoneal folds crossing the duodenum from the cecum and asc colon towards liver and gallblader..
Carefully divide them to relieve duodenal obstruction and mobilize the right colon, allowing it to move to the left.
4. Broadening of small intestine mesentery.
Mobilize the duodenojejunal junction by dividing the ligament of Treitz and straightening the duodenum.
Widen the mesenteric base to expose superior mesenteric vessels by dividing thickened peritoneum and fibrous tissue between the duodenum and colon, taking care to protect the SMA and SMV. This step reduces the risk of recurrent volvulus.
5. incidental Appendectomy
Because the cecum will now lie in the left upper quadrant, future appendicitis would present atypically. An appendectomy is usually performed to avoid diagnostic confusion later.
1.Reposition bowel:
The bowel is returned into the abdominal cavity with Small intestine on the right, colon on the left (non-rotated position). This Arrangement is in a position that minimizes twisting risk. Do not fix the bowel in placebut is rec
detail the laparascopic repair of malrotation
LAPAROSCOPIC CORRECTION OF MALROTATION
1.Place the patient supine in a reverse Trendelenburg position (head elevated) to improve visualization. The surgeon will stand at the child’s feet with the assistant positioned to the surgeon’s left. Insert a nasogastric/orogastric tube to decompress the stomach. Create pneumoperitoneum (8–12 mmHg). Insert ports:
* Umbilical port for the camera.
* Right lower quadrant and left mid-abdomen ports for instruments.
* Optional fourth port (RUQ) for liver retraction.
2. Inspect the abdominal cavity to confirm malrotation (look for high/medial cecum, abnormal ligament of Treitz, elongated duodenum). Assess the mesenteric base width** — if it is narrow, a Ladd’s procedure is necessary.
* If bowel looks strangulated or necrotic, convert to open surgery.
3. If a midgut volvulus is present, untwist it anticlockwise carefully. Check bowel viability after detorsion.
* If bowel is very dilated or visualization is poor, consider converting to open.
4. Identify and divide peritoneal Ladd’s bands crossing the duodenum to relieve obstruction. Mobilize the duodenum and straighten it by dividing the ligament of Treitz. Carefully divide thickened fibrous tissue in the root of the mesentery to widen the base, avoiding injury to the SMA/SMV.
* Repair any internal hernias if present.
5. Reposition the bowel in a non-rotated configuration:
* Small intestine → right side
* Colon → left side
* This arrangement minimizes future volvulus risk.
6. Perform appendectomy to avoid future diagnostic confusion (since the cecum is no longer in the RLQ). Can be done:
* Extracorporeally: deliver appendix through port site.
* Intracorporeally: ligate with endoloop or stapler.
7. Inspect for bleeding or injury. Remove instruments under direct vision and close the port sites with absorbable sutures. Postoperative care: usually start clear fluids on day 1, discharge by day 1–2 if stable.
This operation can be done laparoscopically in children with corrected major exomphalos or congenital diaphragmatic hernia
anatomy of the midgut
Starts from opening of the bile duct into the 2nd part of the duodenum and ends At the junction of the proximal 2/3 and distal 1/3 of the transverse colon |
DERIVATIVES OF THE MIDGUT
From proximal to distal:
1. Distal half of the duodenum (beyond the bile duct opening)
2. Jejunum
3. Ileum
4. Cecum
5. Appendix
6. Ascending colon
7. Proximal 2/3 of transverse colon
BLOOD SUPPLY (TRACED TO THE HEART)
Main Artery: Superior Mesenteric Artery (SMA)**
Left ventricle** → pumps blood into the
⬇
2️⃣ Ascending aorta → continues as the
⬇
3️⃣ Arch of the aorta → then the
⬇
4️⃣ Descending thoracic aorta → passes through the diaphragm (T12) to become the
⬇
5️⃣ Abdominal aorta → gives off the
⬇
6️⃣ Superior mesenteric artery (SMA) (arises at L1 level, just below celiac trunk).
Branches of SMA supplying the midgut:
Branch Supplies
Inferior pancreaticoduodenal artery Lower part of duodenum and head of pancreas (anastomoses with superior pancreaticoduodenal from celiac trunk)
Jejunal and ileal branches Loops (arcades) supplying jejunum and ileum
Ileocolic artery Terminal ileum, cecum, appendix, and lower ascending colon
Right colic artery Ascending colon
Middle colic artery Proximal 2/3 of transverse colon
Venous Drainage
Midgut veins → SMV → Portal vein → Liver → Hepatic veins → IVC → Right atrium
LYMPHATIC DRAINAGE
* Mesenteric lymph nodes → drain into Superior mesenteric lymph nodes** → then Cisterna chyli** → Thoracic duct → Left venous angle (junction of left subclavian and internal jugular veins).
NERVE SUPPLY
Type Source Function
Sympathetic Thoracic splanchnic nerves (T9–T12) → superior mesenteric ganglion ↓ Motility, vasoconstriction
Parasympathetic Vagus nerve (cranial X) ↑ Motility, secretion
Sensory (afferent) Accompanies sympathetic fibers Pain sensation (e.g., colic)
post op care of malrotation
Postoperative Care
In patients without evidence of volvulus or obstruction, a nasogastric tube is not generally needed postoperatively.
Bowel function generally returns in 1–2 days if the laparoscopic approach was utilized.
However, older patients with chronic obstruction are likely to have a prolonged ileus, and thus nasogastric drainage and parenteral nutritional support may be required until return of bowel function.
Patients with extended or subtotal small bowel resection pose special problems. Total parenteral nutrition is essential
to sustain these patients until adaptation and compensatory growth of the residual bowel can occur.
Return of bowel function may be delayed for prolonged periods during which parenteral nutrition may be required but, in general, oral nutrition can be resumed in 5-7 days. Infants who have undergone massive small bowel resection will require parenteral nutrition for many months pending adaptation of the residual intestine.
Structure | Final Position |
post op complications of malrotation
adhesive small bowel obstruction (10%),
recurrent volvulus,
short gut syndrome. Diarrhea & dehydration in short bowel syndrome
Postoperative intussusception
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GASTROSCHISIS & OMPHALOCELE66
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INGUINAL HERNIAS59
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ANORECTAL MALFORMATIONS47
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TEF/OA42
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HIRSCHSPRUNG DISEASE37
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PEDIATRIC BURNS (SURGERY)34
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PEDIATRIC INTUSSUSCEPTION35
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APPENDICITIS30
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NECROTIZING ENTEROCOLITIS26
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PEDIATRIC TRAUMA24
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UNDESCENDED TESTICLE24
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MALROTATION23
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PYLORIC STENOSIS18
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NEONATAL INTESTINAL OBSTRUCTION16
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STOMA15
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Wilms Tumor0
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FB INGESTION/INHALATION0
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GI ATRESIAS0
