The patient is a 70-year-old male, status-post laparoscopic-assisted colon resection for recurrent tumor at a previous ileocolic anastomosis. The patient did well initially, then had increasing abdominal pain. Plain films were consistent with a small bowel obstruction. Compted tomography was followed by a barium enema, then laparotomy.
The patient is a 70-year-old male, status-post
laparoscopic-assisted colon resection for recurrent tumor at a
previous ileocolic anastomosis. The patient did well initially,
then had increasing abdominal pain. Plain films were consistent
with small bowel obstruction. Computer tomography was followed by a
barium enema, then laparotomy.
Richters' hernia at the trocar site causing small bowel
An enhanced CT scan of the patient's abdomen showed dilated
loops of small bowel with no passage of contrast to the colon. The
subcutaneous lucency at the trocar site was felt to represent
unresorbed post-operative air (figure 1). A barium enema was
performed to evaluate the anastomosis. A spot-film tangential to
the abdominal wall (figure 2) showed a collapsed loop of small
bowel (black arrow) incorporated into the trocar site. The lucency
leading from the contrast-filled bowel to the staples represents
the hernia tract (arrowheads). At surgery, a length of small bowel
(approximately 2 cm) was found incarcerated between the peritoneum
and the external oblique muscle. The hernia was reduced without
injury and the defect was repaired.
Complications of laparoscopic surgery are uncommon,1,2 and may
be directly related to the type of surgery performed (e.g., bile
duct injury during laparoscopic cholecystectomy) or to the
laparoscopic entry itself. Complicatons to the latter include
abdominal wall bleeding, omental bleeding, abdominal vessel injury,
bladder and bowel perforation, solid visceral injury, and
infection.3,4 Trocar site hernias occur infrequently, with a
reported incidence of 1 to 3.6%.5,6 However, some authors claim
that trocar site hernias are under-reported and that the incidence
is probably somewhat higher.5,6
Even when trocar site hernias are asymptomatic they can result
in small bowel obstruction.6 Occasionally the hernia responsible
for the obstruction is the Richters' type.5 Richters' hernias
result when a knuckle of bowel becomes lodged in a small opening,
classically the femoral canal.2 Richters' hernias also can occur at
trocar sites because of a small (10 to 15 mm) defect left after
trocar sheath removal.2,5 Generally, the bowel lumen remains
patent, resulting in partial obstruction. Consequently, surgical
repair may be delayed, increasing the possibility of partial
thickness bowel infarction, perforation, and resulting
peritonitis.2 Richters' hernias are difficult to diagnose
preoperatively because they generally have no palpable mass and
there is no obvious herniation of a bowel loop on CT. As with our
case, the clinical picture is often confusing in that a
post-laparoscopic patient presents with bowel obstruction of
unclear etiology. Patient presentation of small bowel obstruction
due to trocar site hernia from one day to one year after surgery
has been reported.5,6 Others may remain occult for longer periods
It seems reasonable that the radiologist should consider a
trocar site hernia in any post-laparoscopic patient presenting with
small bowel obstruction regardless of the time since surgery. A
knowledge of the technical aspects of laparoscopic surgery and
standard locations of trocar sites will allow careful inspection of
both plain films and CT scans. This may lead to early diagnosis,
which can help guide operative repair alternatives, such as
utilizing a local approach instead of exploratory laparotomy. In
addition, the possibility of bowel ischemia may be reduced with
early intervention. Lastly, with the rise in the number and
complexity of laparoscopic procedures performed, an increased
awareness of this entity is important, as these characteristic
hernias will be encountered in greater numbers.
1. Schiller V, Joyce P, Sarti D: Small bowel obstruction due to
hernia through the primary laparoscopic port: A complication of
laparoscopic cholecystectomy [letter] AJR 163:480, 1994.
2. Hass B, Schrager R: Small bowel obstruction due to Richters'
hernia after laparoscopic procedures. J Laparoendosc Surg
3. Ray C, Hibbein J, Wilbur A: Complications after laparoscopic
cholecystectomy: Imaging findings. AJR 160:1029-1032, 1993.
4. Wright T, Bertino R, Bishop A, et al: Complications of
laparoscopic cholecystectomy and their interventional radiologic
management. Radiographics 13:119-128, 1993.
5. Plaus W: Laparoscopic trocar site hernias. J Laparoendosc
Surg 3:567-570, 1993.
6. Boike G, Miller C, Spirtos N, et al: Incision bowel
herniations after operative laparoscopy: A series of nineteen cases
and review of the literature. Am J Obstet Gynecol 172:1726-1733,
7. Miller P, Mezwa D, Feczko P, et al: Imaging of abdominal
hernias. Radiographics 15:333-347, 1995.
Prepared by Glenn G. Gray, MD, Alan Tikotsky, MD, Department of
Radiology; and A. Douglas Heymann, MD, Department of Surgery, Lenox
Hill Hospital, New York, NY.