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21 Small Bowel Obstruction 227
anecdotal at best. We do not practice them. Occasionally, a patient develops
obstruction early in the aftermath of an operation for adhesive SBO; this is a case
par excellence for prolonged nonoperative management, with the patient maintained on total parenteral nutrition (TPN) until adhesions mature and the obstruction resolves. (See also > Chap. 48.)
A Word About Patience
You will understand by now that in some circumstances a laparotomy for
SBO will be a long and difficult operation due to multiple adhesions or radiation
enteritis, for example. If you begin an operation expecting a quick-and-easy procedure and are then confronted by a nightmare abdomen, the first thing you must
do is reset your mental clock. Failure to do this may mean that you will attempt to
rush the procedure, and this inevitably leads to disaster, with multiple inadvertent
enterotomies, peritoneal contamination, and ultimately an even longer and more
dangerous procedure. Upon entering such a disastrous abdomen unexpectedly,
inform everybody immediately that the procedure is now going to take a few hours
while you unravel all the loops necessary to get at the problem and fix it. And then,
take your time and fix it carefully and slowly.
Gallstone Ileus
Gallstone ileus develops typically in elderly patients with long-standing
cholelithiasis. It is caused by a large gallstone eroding into an adjacent segment
of bowel—usually the duodenum; then, the gallstone migrates distally until
stranded at the narrow ileum. Presentation is usually vague as initially the stone
may disimpact spontaneously, causing intermittent episodes of partial obstruction. Yo u will never miss the diagnosis once you habitually and obsessively search
for air in the bile ducts on any plain abdominal X-ray you order (> Chap. 5). The
air enters the bile duct via the enterocholecystic fistula created by the eroding
gallstone. Treatment is operative and should be tailored to the condition of the
patient. In frail and sick patients, deal only with the SBO: place an enterotomy
proximal to the stone and remove it and search for additional stones in the bowel
above; you do not want to have to re-operate. In patients who are younger and
reasonably fit and well, you may want also to deal with the cause of the problem—the gallbladder. Perform a cholecystectomy and close the duodenal defect;
place your suture line transversely to avoid narrowing of the duodenum. But
again, not removing the gallbladder after dealing with the obstructing gallstone
is a perfectly reasonable option.
228 Moshe Schein
Bezoars
Bezoars are tightly packed collections, or “balls,” of partially digested or
undigested material forming in the stomach and then migrating distally, where
they may obstruct the terminal ileum. You may encounter one of the following
types of bezoars:
Phytobezoars: partially digested agglomerations of vegetables or fruits that
form in patients with altered gastric physiology (e.g., following gastric resection,
vagotomy, or bariatric operation and even in patients with diabetic gastroparesis)
or health food “crazies” and elderly forget-to-chewers. Many sorts of fruits and
vegetables are implicated, particularly when consumed in large quantity (I once
suffered partial SBO after consuming, within an hour, a whole bag of baby carrots), but consumption of persimmons is especially notorious in this regard, with
patients developing multiple episodes of SBO.
Trichobezoars: these most commonly occur in younger patients with psy-
chiatric disturbances who chew and swallow their own hair. Trichobezoars form
in the stomach and often reach a huge size; they break into smaller pieces and
migrate into where they can obstruct at several points.
Parasitic bezoars: consisting of conglomerates of parasites such as Ascaris
lumbricoides, these may obstruct the distal ileum. Obviously, these are common in
endemic areas.
Patients present usually with features of partial or smoldering SBO and a
virgin abdomen. History is suggestive, and CT images—showing the actual
intraluminal bezoars—are diagnostic. As mentioned, Gastrografin challenge can
dislodge the obstructing parasites, or other types of bezoars, pushing them into
the cecum. But when the obstruction is complete, you have to operate and deal
with the obstructing bezoar like you did with the gallstone (see the section on
gallstone ileus). It is crucial to palpate the entire small bowel, including the duodenum (and the stomach), for additional bezoars and remove all of them.
Preoperative CT may be helpful in mapping such additional bezoars for you. You
do not want the patient to develop early postoperative SBO caused by a missed
bezoar—needing another laparotomy for removal—do you?
SBO After Gastrectomy
With the disappearance of gastrectomies performed for benign disease
and the declining rate of gastric cancer, there are not too many postgastrectomy patients to present with SBO, but some do. According to my friends
Professor David Dent (Cape Town, South Africa) and Dr. Hernan Diaz
21 Small Bowel Obstruction 229
(Santiago, Chile)—both of them “old gastrectomists”—the reasons for SBO
in these patients are:
Simple adhesive obstruction—what is common is common
Recurrent gastric carcinoma, with loops of bowel “frozen” by peritoneal
carcinomatosis
Bolus obstruction by bezoars
Internal herniation of small bowel through defects of the mesocolon or
behind the jejunal loop forming the Billroth II (or Roux-en-Y) gastroenterosotomy—be it antecolic or retrocolic
Twisting or volvulus of redundant afferent or efferent jejunal loops
Obviously, the more complex the original postgastrectomy reconstruction, the
more potential peritoneal defects created, and the “looser” the various intestinal loops,
the higher the risk will be for bowel to kink, rotate, herniate, and obstruct. (Now you
understand why we prefer Billroth I reconstruction after gastrectomy; > Chap. 17.)
Another specific type of obstruction is the jejunogastric intussusception.
Both the afferent or efferent loops can invaginate into the gastric remnant, but
the retrograde efferent loop intussusception is more common. This can occur
from a few days up to many years after the gastrectomy. Sudden onset of epigastric pain, vomiting, and hematemesis and a palpable epigastric mass in a patient
with previous gastric surgery are the classic triad.
Obstruction of the afferent loop after Billroth II or Roux-en-Y reconstruc-
tion—by whichever of the mentioned mechanisms—produces a closed-loop obstruction (between the obstructing point and the duodenal stump). High
intraluminal pressures are commonly associated with elevation of serum pancreatic enzymes (amylase) and, if the obstruction is not relieved, with necrosis of the
involved loop and the attached duodenum. The clinical picture of epigastric pain,
upper abdominal mass, and hyperamylasemia may confuse you to think that you
are dealing with acute pancreatitis.
The proximal location of the obstruction is suggested by the frequent vomiting, lack of abdominal distention, and paucity of dilated small bowel on plain
abdominal X-ray. CT with oral contrast is a superb diagnostic aid, showing the
exact anatomy of obstruction and the ring sign of small bowel within the stomach in the case of jejunogastric intussusception. Occasionally, endoscopy is
needed to clarify the picture. Do understand that acute afferent loop obstruction
is a dire emergency; you have to operate before the closed-loop obstruction
results in complete necrosis of the duodenum!
At operation, the anatomy has to be restored, and this entails resection of
nonviable loops of bowel and reconstruction of the upper gastrointestinal tract,
as you would do after partial or total gastrectomy.
230 Moshe Schein
Small Bowel Volvulus
Small bowel volvulus is also called midgut volvulus, distinguishing it from
foregut volvulus (> Chap. 16) and hindgut volvulus (> Chap. 25).
Volvulus, the “twisting strangulation” of an intestinal segment around an
axis formed by a band or an adhesion, is a common occurrence in adhesive SBO.
A narrow-based loop of small bowel suspended by a Meckel diverticulum can also
undergo torsion. But, what about “spontaneous” volvulus, one that involves the
entire, or almost entire, small intestine?
Spontaneous volvulus of the small bowel, while very rare in the “developed
world,” is not uncommon in rural areas of the Indian subcontinent, central Asia,
and Africa. It seems more common in healthy farmers returning home for a large
evening meal or, in Moslem countries, during the fast of Ramadan—when large
meals are consumed at night after the day of fasting. The common pathway appears
to be a huge load of high-fiber, indigestible food, arriving suddenly in an empty
small bowel. The sudden distention creates rotational kinking forces. At operation,
typically the twisted bowel is loaded with liters of claylike undigested food and is
often suspended on an unusually long mesentery. Occasionally, small bowel volvulus occurs in combination with that of the sigmoid colon, forming the so-called
ileosigmoid knot, in which the ileum and the sigmoid entangle each other to form
a knot and become gangrenous. An arrangement of the small bowel and sigmoid
colon on long, narrow mesenteries would appear to be a prerequisite.
Like in any other condition resulting in an acute vascular compromise of
the bowel, patients present with severe central abdominal pain that is out of pro-
portion to the abdominal findings; systemic signs of hypovolemia and toxemia
are however dramatic and dominant. An urgent operation is indicated, during
which the ischemic intestine is managed as discussed above and in > Chap. 23.
Intestinal Malrotation
Most cases of midgut malrotation present within the first weeks or months
of life. The rest can present sporadically throughout childhood and even in adults.
The anatomy of malrotation is depicted in > Figure 21.2: note how close the
D-J flexure (point X) is to the cecum (point Y) and how narrow the base of the
mesentery is and thus prone to torsion. Strangulating midgut volvulus in these
patients can present acutely, but more commonly, especially in older children and
adults, volvulus is preceded by recurring attacks of upper and central abdominal
colicky pain and intermittent vomiting of bile and is often relieved by diarrhea.
Once again, patients presenting with acute midgut volvulus are in great pain and
appear ill but have minimal abdominal findings on examination.
21 Small Bowel Obstruction 231
A.
B.
C.
A. Normal
B. Malrotation
C. Following Ladd’s procedure
X: D-J junction
Y: Cecum
B.
Fig. 21.2. Small bowel malrotation and volvulus. (Modified from George
G. Youngson, Common Pediatric Disorders. http://www.rcsed.ac.uk/eselect/sig2.htm)
Classically, the diagnosis was achieved by contrast studies: upper gastrointestinal barium examination showing loss of the duodenal C (corkscrew duodenum)
and the D-J flexure to the right of the midline. Barium enema would show the
cecum riding high under the liver. CT, however, has become the optimal diagnostic
modality, showing the small bowel located entirely within the right hemiabdomen
and the colon situated on the left. Features of the twisted mesentery and intestinal
wall ischemia are seen as well. Midgut volvulus can also be diagnosed on Doppler
ultrasound by demonstrating the “whirlpool sign”— wrapping of the superior
mesenteric vein and the mesentery around the superior mesenteric artery.
Emergency laparotomy is mandated. Remember that these patients are
grossly hypovolemic and need aggressive fluid resuscitation. At operation, detort
the twisted bowel, working in a counterclockwise rotation. Dead bowel needs
resection, usually massive resection. Regarding whether to anastomose and
whether second-look operation is necessary, see > Chap. 23.
After resecting the dead bowel or convincing yourself that it is viable, you
want to address the anatomical pathology of malrotation by doing what has been
described by William E. Ladd (1880–1967):
232 Moshe Schein
1. Divide the peritoneal folds (Ladd bands) that cross from the cecum to the liver,
compressing the duodenum.
2. Mobilize the right colon.
3. Mobilize the D-J flexure, freeing the ligament of Treitz—straightening the
duodenal loop.
4. Divide any thick peritoneal folds compressing the SMA.
5. Place the bowel in a new pattern as depicted in > Fig. 21.2c; note that now point
X is far from point Y.
6. Remove the appendix to prevent “atypically situated” appendicitis.
Obviously, after having to resect most of the small bowel you do not worry
about recurrence of the volvulus, and there is no impetus to correct the anatomy,
except points 1, 4, and 6.
Prognosis
Overall, about half the patients presenting with an adhesive SBO can be managed without an operation. About a third of patients operated once for adhesive
SBO will have recurrent problems within 30 years. For patients admitted several
times for adhesive SBO, the relative risk of recurrence increases with increasing
number of prior obstructive episodes; more than two-thirds of patients with four
or more SBO admissions will re-obstruct. In addition, the risk of recurrence is a bit
lower in patients in whom the last obstructive episode was treated surgically, but
this does not mean that those patients who were treated conservatively will have an
increased need for operation during their future admissions for SBO. The aim is
therefore to operate only when necessary but not to delay a necessary operation.
The only thing predictable about small bowel obstruction is its unpredictability.
Acute Abdominal Wall Hernias
Paul N. Rogers
“You can judge the worth of a surgeon by the way he does a hernia.” (Thomas
Fairbank, 1876–1961)
Acute Groin Hernia
In all parts of the world, many more hernias are now repaired electively than
was formerly the case. In spite of this, surgeons are frequently confronted by acute
groin hernias, and it is important to know how to deal with them.
A word about terminology: groin hernias, inguinal or femoral, may be described as reducible, irreducible, incarcerated, strangulated, or obstructed. This
terminology can be confusing, and the words, which have come to mean different things to different people, are much less important than the concepts that
underlie the recognition and management of acute hernia problems. The impor-
tant concept to be grasped is that any hernia that becomes painful, inflamed, or
tender and is not readily reducible should be regarded as a surgical emergency.
22
Presentation
Patients may present acutely in one of two ways:
Symptoms and signs related directly to the hernia itself
Abdominal symptoms and signs, which at first may not seem to be related to a
hernia
The first mode of presentation usually means pain and tenderness in a tense,
irreducible hernia. A previously reducible hernia may suddenly become irreducible. This problem is usually obvious (>Fi g. 22.1).
The second mode of presentation will be much more insidious. Beware the
vomiting old lady! Treated at home for several days by the primary care physi-
cian as a case of gastroenteritis, she eventually comes under the care of the surgeons due to intractable emesis. By this stage, she is dehydrated and in need of
Paul N. Rogers
Department of Surgery, Gartnaval General Hospita l, Glasgow, Scotland
M. Schein et al. (eds.), Schein’s Common Sense Emergency Abdominal Surger y,
DOI: 10.1007/978-3-540-74821-2_22 , © Springer-Verlag Berlin Heidelberg 2010
233
234 Paul N. Rogers
Fig. 22.1. “This must be strangulated, eh?”
much resuscitation. It is surprisingly easy in these circumstances to miss the
small femoral hernia barely palpable in the groin, trapping just enough small
bowel as is required to produce obstruction. No abdominal symptoms or signs
are present, and the plain abdominal radiographs are non-diagnostic. None of
these difficulties saves you from the embarrassment of the following morning’s
round when the hernia is discovered.
Hernias are still one of the most common causes of small bowel obstruction
(> Chap. 21). A careful search must be made for them in all cases of actual or
suspected intestinal obstruction. This may mean meticulous, prolonged, and
disagreeable palpation of groins that have not seen the light of day, let alone soap
and water, for a long time. In most cases, however, the diagnosis is obvious, with
a classical bowel obstruction and a hernia stuck in the scrotum.
Beware the Richter’s hernia, typical of femoral hernias, in which only a
portion of the circumference of the bowel is strangulated. Because the intestinal
lumen is not completely blocked, bowel obstruction may not occur, and presentation is consequently delayed and non-specific.
Preparation
Surgery for acute groin hernia problems should be carried out without undue delay, but these patients must not be rushed to surgery without careful assessment and preparation (
>
Chap. 6). As we suggested, some patients may be in need
of quite a bit of resuscitation on admission to hospital.
22 Acute Abdominal Wall Hernias 235
Analgesia is an important part of the management of these patients. Opiate
analgesia and bed rest with the foot of the bed slightly elevated may successfully
manage a painful obstructed hernia of short duration. Gentle attempts at reduction of such a hernia are justified once the analgesics have taken effect. A successful reduction of the hernia means that emergency surgery at unsociable hours
may be traded for a semielective procedure on the next available routine list, a
benefit for both patient and surgeon. Note that manual reduction of the incarcerated hernia should be attempted only in the absence of signs of intestinal strangulation; it should be gently performed to avoid “reduction en masse”—when the
herniated bowel with the constricting ring are reduced together, providing a
false sense of achievement and a delay of necessary surgery.
The Operation
Inguinal Hernia
An inguinal incision is a satisfactory approach. Even if a bowel resection is
required, it is possible to deliver sufficient length of intestine through the inguinal
canal to carry this out.
The main difference in dissection in an emergency hernia operation compared to an elective procedure is the moment at which the hernial sac is opened.
In the emergency situation, the hernia will often reduce spontaneously as soon
as the constricting ring is divided. The site of constriction may be the superficial
inguinal ring, in which case the hernia reduces when external oblique is opened.
It is recommended, therefore, that the sac be opened and the contents grasped for
later inspection before the constricting tissues are released. If the hernia reduces
before the sac contents are inspected, it is important that they are subsequently
identified and retrieved so that a loop of non-viable gut is not inadvertently left
in the abdomen. Retrieval of reduced sac contents can be an awkward business
via the internal ring, and occasionally a formal laparotomy may be required to
inspect matters properly. It is for these reasons that great care should be taken to
secure the sac contents for inspection as soon as possible during the procedure.
If the hernial sac contains omentum only, then any tissue that is necrotic or
of doubtful viability should be excised, ensuring meticulous hemostasis in the
process. If, on the other hand, bowel is involved, then any areas of questionable
viability should be wrapped in a warm, moist gauze pack and left for a few minutes
to recover. Irretrievably ischemic gut should be resected. If there is a small patch
of necrosis that does not involve the whole circumference of the bowel, then this
can s ometime s be dea lt w ith by inva ginat ion rat her t han by res orting to rese ctio n.
In this situation, the injured bowel wall is invaginated by a seromuscular suture,
taking bites on the viable bowel on either side of the defective area of gut.
236 Paul N. Rogers
Occasionally, particularly if a bowel resection has been necessary, oedema
of the herniated gut makes its replacement in the abdomen difficult. Manoeuvers
such as putting the patient into a marked Trendelenburg position and gently
compressing the eviscerated gut, covered by a large, moist gauze swab, will almost invariably allow the bowel to be replaced in the abdomen. It is possible to
minimize the chances of this difficulty arising if care is taken during any bowel
resection not to have any more gut outside the abdomen than is absolutely necessary. Very rarely the herniated viscera will not return to the abdomen without
pulling on it from within; in such instances, La Rocque’s manoeuver may be useful: extend the skin incision up and laterally, then extend the split of the external
oblique aponeurosis and follow this with a muscle-splitting incision of internal
oblique and transverse muscles above the internal ring. Through this incision
you enter the peritoneal cavity and reduce the herniated viscera from within.
The question of the type of hernia repair to be employed is a matter for the
individual surgeon, with one proviso. In these days of tension-free hernia repair,
it seems imprudent to place large amounts of mesh in the groin if necrotic gut has
had to be resected. In this situation some other type of repair seems advisable to
obviate the prolonged misery of infected mesh.
Femoral Hernia
You can approach the acute femoral hernia from below the inguinal canal,
from above, or through it.
With the low approach, you place the incision below the inguinal ligament,
directly over the bulge. You find the hernial sac and open it, making sure to
grasp its contents for proper inspection. Strangulated omentum may be excised,
and viable bowel is reduced back into the peritoneal cavity through the femoral
ring. When the ring is tight, and usually it is, you can stretch it with your small
finger, inserted medially to the femoral vein; occasionally, you will have to cut the
lower fibres of the overlying inguinal ligament to let your finger enter the femoral
canal. You can resect non-viable small bowel through this approach and even
anastomose its ends, but pushing the sutured or stapled anastomosis back into
the abdomen is like trying to squeeze a tomato into a cocktail glass. Therefore,
when bowel has to be resected, it is advisable to do it through a small right (or left)
lower quadrant muscle-splitting laparotomy (as for appendectomy).
Some authorities favour an approach via the inguinal canal but we see little
merit in this approach, which must disrupt the anatomy of the canal and presumably risk a subsequent inguinal hernia.
Yet another approach is McEvedy’s. This involves an approach to the
extraperitoneal space along the lateral border of the lower part of rectus
abdominis. The skin incision may be vertical, in line with the border of rectus,
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