Internal Hernias Involving the Sigmoid Mesocolon
CAPT. J. ROBERT BENSON,** MC, USA, CAPT. DUNCAN A. KILLEN,*§
From the Department of Surgery, Walter Reed General Hospital,
WRAMC, Washington 12, D. C.
INTERNAL hernias account for only a
small percentage of all instances of intesti-
nal obstruction. Hernias which result from
defects, or abnormalities of the sigmoid
mesocolon are among the rarer types of
internal hernia. Management of a patient
who presented with intestinal obstruction
due to a previously unreported variant of
such internal hernias prompted this report.
This 42-year-old woman was admitted to De-
Witt Army Hospital on September 4, 1962, with
a four day history of intermittent, cramping pain
in the lower abdomen. This was associated with
obstipation and slight abdominal distention, but
without nausea or vomiting. There was no history
of previous similar episodes of abdominal pain
or prior abdominal operation.
Physical examination revealed the patient to
be well developed, well nourished, and in no
distress. Temperature was 370 C., pulse 88, and
blood pressure 120/88. The abdomen was slightly
distended, but soft without tenderness, spasm, or
masses. No external hernia was present. Pelvic
examination was normal. The remainder of the
physical examination was unremarkable.
Laboratory examination revealed a hematocrit
of 44 per cent and a white blood cell count of
8,000 (following hydration). Roentgenogram of
the chest was normal. Flat and upright roentgeno-
grams of the abdomen showed slight distention
of two loops of small bowel with air-fluid levels.
There was a small amount of colonic gas present.
The patient was given nothing by mouth and
parenteral fluids were administered. There was
subsidence of all symptoms and persistence of a
good appetite. Bowel sounds were normal and
abdominal examination remained essentially un-
changed. X-ray of barium enema of the colon was
*Submitted for publication March 12, 1963.
Resident, General Surgery Service.
Surgical Service, DeWitt Army Hospital,
Fort Belvoir, Virginia.
normal. Despite nasogastric suction, repeated ab-
dominal roentgenograms showed progressive
crease of the small bowel distention.
September 10, 1962. At operation, the colon and
terminal ileum were found collapsed. Proximal
small bowel was
inches from the ileocecal valve, the ileum entered
the ring of an internal hernia
hernial ring was oval, 2 cm. in diameter, and
situated in the left leaf of the mesosigmoid. The
ileum passed anterior to the sigmoid colon to
enter the defect where the small bowel was en-
carcerated. The ring of the sac was incised, re-
leasing a 15 cm. segment of viable ileum. Exami-
revealed that the ring of the sac was formed by
the left peritoneal leaf of the mesosigmoid, im-
hernial sac itself was contained within the meso-
sigmoid and extended caudally into the presacral
space, posterior to and to the left of the upper
rectum. The hernia did not involve the sciatic
foramen. The hernial defect was repaired with
interrupted silk sutures. An incidental appendec-
tomy was performed. No other intra-abdominal
abnormality was found.
The postoperative course was uneventful. The
September 29, 1962. Her subsequent course has
to the sigmoid
Internal hernias account for between 1
and 3 per cent of all instances of intestinal
obstruction.2'7 The more frequently en-
countered internal hernias are those related
to the paraduodenal fossae, the paracecal
fossae, defects of the small bowel mesen-
foramen of Winslow. Hernias involving the
sigmoid mesocolon account for only about
5 per cent of all internal hernias,4 there