Volvulus of the sigmoid colon

A high-fibre diet has many advantages, which are said to include the low incidence of appendicitis, and a much lower incidence of carcinoma and diverticula of the colon. But it may have at least one disadvantage. A large sigmoid colon distended with the gas of a high-fibre diet is more liable to twist on its mesentery. This is the commonest cause of large gut obstruction in most communities in the developing world, particularly in Africa, and is sufficiently characteristic to allow you to diagnose it before you do a laparotomy. If an obstructed sigmoid colon strangulates, its wall will become gangrenous, and may perforate. Sigmoid volvulus is however less dangerous and more common than volvulus of the small gut.

There are several kinds of sigmoid volvulus: (1) The common volvulus of the large thick-walled pelvic colon that is usual in people who eat a high-fibre diet, and which usually presents subacutely. (2) The less common volvulus of the thin-walled type of pelvic colon which usually presents acutely. (3) A rare compound volvulus in which the small gut twists around a volvulus of the sigmoid (see under ''Difficulties' at the end of this section).

The common subacute volvulus typically occurs in an adult man (it is rare in women) whose first symptom is difficulty passing flatus. This is followed over a few days by increasing abdominal distension, so that by the time you see him his abdomen is hugely distended and tympanitic (''like a drum'), but is not very painful or tender. He may be so distended, especially on the left, that he is hardly able to breathe. Despite the distension, his abdomen is usually soft enough for you to be able to feel his sigmoid as an enormous loop rising out of his pelvis, like a motor cycle tyre, towards one or other costal margin. Vomiting is unusual, except perhaps once at the start of the attack. His general condition is usually good: he can drink and is not dehydrated. The contrast between his satisfactory general state, and his huge abdomen is striking[md]unless he presents late, in severe shock.

He may have had several previous milder attacks, during which twisting and subsequent release of his colon caused abdominal pain and constipation, followed by diarrhoea with much flatus.

The uncommon acute volvulus seems to occur more frequently in areas where sigmoid volvulus is relatively uncommon. Of the few women who do have volvulus, most have the acute form. A patient's first symptom is colicky, central lower abdominal pain, which is severe enough to make him seek early treatment. At the onset he may have an urge to defaecate, but only passes a small stool, perhaps followed by a little blood. He may vomit at the onset, and frequently later.

He is anxious and in pain, his pulse is rapid, his temperature raised, and his blood pressure low. His abdomen is only moderately distended, but it is tense and tender, and the individual loops of his colon are difficult to feel. He has nearly a 50% chance of developing gangrene, peritonitis, and shock within 24 hours.

Some patients fall midway between these two extremes. Remember also that gangrene may occur after many days of subacute volvulus.

X-rays are useful[md]an erect abdominal film is usually diagnostic: (1) In the subacute form there is a huge gas shadow like an inverted ''U' reaching from his pelvis to his upper abdomen, inclining right or left, often with smaller fluid levels proximal to the loop (A, 10-14). (2) A supine film may show three dense curved lines converging on his left sacroiliac joint. The middle line is the most constant one, and is caused by two walls of the distended loop lying pressed together (B, 10-14).

Management. Subacute volvulus is an obstruction to the passage of flatus, usually without damage to a patient's gut or its blood supply. You can usually relieve it without operation. (1) Try to deflate his dilated sigmoid colon with a sigmoidoscope. You have a 50% to 90% chance of success, depending on the area. (2) If you fail do a laparotomy: (a) If his sigmoid is gangrenous, he has a 50% chance of death. You will have to resect it urgently, either by exteriorization or by Hartmann's procedure (10-16), depending on how much of it is gangrenous, and whether or not you can bring the distal end of his gut to the surface. (b) If his sigmoid is not gangrenous you can untwist it. This will relieve his immediate symptoms, but it is not sufficient treatment, because his volvulus has at least a 30% chance of recurring (some say 90%). After a second attack it has a 60% chance of doing so. To avoid this: (i) You can close his abdomen and ask him to return later for an interval resection of his colon, or you can refer him to have this done. Unfortunately, he will probably think himself cured, and so be unlikely to return. (ii) You can resect his colon and leave him with a temporary pelvic colostomy[md]which will certainly make him return! (iii) You can resect and anastomose his colon, and protect it with a transverse colostomy. Whatever you decide to do, don't just do a resection and anastomosis, without doing a protective transverse colostomy also[nd]the risk of peritonitis is too great.

If you are unskilled, (i) is best. If you have some experience do (ii) or (iii). An interval resection of the sigmoid colon involves excising his sigmoid and joining its ends. This is a moderately difficult elective procedure, so it is not described here.

The main danger in deflating a patient with a sigmoidoscope is that you may miss gangrene, and not operate when you should. But this should be rare, if you follow the method described below. An intussusception usually shows you that gut is gangrenous by the passage of blood and mucus rectally. Unfortunately, a gangrenous sigmoid colon rarely produces these clues, so that finding out if it is gangrenous or not is more difficult.

If you have to resect a sigmoid colon, you can always mobilize enough healthy descending colon proximally to reach the surface of the patient's skin and make a colostomy. If he has enough healthy colon distally, you can exteriorize his gangrenous sigmoid, and make a double-barrelled colostomy out of both ends (9-19 and 10-16). But, if his sigmoid is gangrenous right down to his rectosigmoid junction, he will not have not enough healthy colon distally to reach his abdominal wall. So you will have to do close his rectum and drop it back into his pelvis (Hartmann's operation).

If he has enough healthy colon distal to the the diseased segment to reach the skin of his abdominal wall (there is always enough proximally), you can, if you wish, exteriorize (9.6) the gangrenous area. Take it out of his abdominal cavity, close the wound round it, and then cut off the gangrenous part. This reduces the risk of contaminating his peritoneal cavity. If his abdomen is very distended, you may have to do this through the main wound, rather than a stab wound, which is preferable.

If possible, refer him to have his colostomy or Hartmann's procedure closed. If not, close his colostomy as in Section 9.5 and Hartmann's procedure as in Section 10.10a. He will not like being left with a colostomy.

Temporary colostomy as a permanent treatment for sigmoid volvulus. As we go to press an account has just reached us of simple one-stage method of treating non-gangrenous cases of sigmoid volvulus. If his sigmoid is viable you can pass a Foley catheter into it through his abdominal wall. When you withdraw the catheter the stoma will close spontaneously, and enough adhesions will have formed to make recurrence unusual. This appears to be a useful method for the inexperienced operator who does not want to attempt elective sigmoid resection (the best method).

Odonga AM, ''Varieties of intestinal volvuli seen at Mulago Hospital Kampala' (1966[nd]1975), East African Medical Journal 1982;59:711[nd]7. Mout P, ''Temporary colostomy as a permanent treatment for sigmoid volvulus: a simple and safe one-stage procedure'. Tropical Doctor 1989;19:28[nd]30. IF YOU SUSPECT GANGRENE, OPERATE Fig. 10-14 SIGMOID VOLVULUS. A, a supine X-ray showing a huge distended inverted loop of sigmoid. B, is a diagrammatic version of A, to show three lines formed by the walls of the patient's sigmoid converging on his left sacroiliac joint. C, the abdominal distension caused by sigmoid volvulus. D, E, and F, show the mechanism of sigmoid volvulus. G, sigmoidoscopy in the knee-elbow position. H, a large rectal or stomach tube for sigmoidoscopic reduction. Partly adapted from drawings by Frank Netter, with the kind permission of CIBA-GEIGY Ltd, Basle (Switzerland).

SIGMOID VOLVULUS For the general method for gut obstruction see Sections 10.3 and 10.4.

DIFFERENTIAL DIAGNOSIS. Carcinomatous obstruction of the left colon or rectum is the main one (a rectal examination should exclude the latter). The enormous gastric distension of pyloric obstruction can confuse you; so can caecal volvulus.

Suggesting carcinoma of the colon[md]a change from a normal bowel habit to constipation over a much longer period; a smoothly distended abdomen without obvious coils of colon; X-rays showing caecal distension, and not the characteristic signs of sigmoid volvulus.

CAUTION ! Be on your guard if the patient is a woman. In Uganda volvulus in a woman is likely to be acute or compound.

MANAGEMENT. Suspect that a patient's gut has strangulated if: (1) His symptoms started abruptly, with severe pain, especially radiating to his back. (2) He is ill, with a raised pulse, fever, or a low blood pressure. (3) He has signs of peritonism[md]tenderness, guarding, and absent bowel sounds. (4) His mucosa is discoloured at the limit of sigmoidoscopy. (5) A rectal tube yields blood-stained fluid. (6) X-rays show gas in his peritoneal cavity. This is likely to be a late sign and mean that an operation is almost hopeless.

If you suspect strangulation do an immediate laparotomy.

If he presents in a subacute attack, and you are fairly sure of the diagnosis, and do not suspect gangrene, deflate him at sigmoidoscopy.

DEFLATION AT SIGMOIDOSCOPY. A sigmoidoscope, a well lubricated rectal tube[md]and a sense of humour! If you don't have a sigmoidoscope, or its light does not work, you may succeed in deflating him with a soft rubber tube while he is in the knee- elbow position. Take blood for cross-matching.

Take him to the theatre, prepared for a laparotomy, in case sigmoidoscopy fails, or you perforate his gut. Put him into the knee-elbow position, as in G, Fig. 10-14. The weight of fluid in the loop will pull the apex out straight. You will also be less likely to get an eyeful of faeces when an explosive burst from the rectal tube splatters you in the face. Pass the sigmoidoscope (22.1). It usually travels 15 cm before it reaches a point where the lumen is narrowed and the colon is twisted, but you may have to pass it to 30 cm. When you reach the twist, look at the mucosa carefully.

CAUTION ! (1) Don't anaesthetize him or give him a heavy sedative. Pain during or after sigmoidoscopy is a useful indication of trauma or gangrene. (2) If his sigmoid is gangrenous, deflating it is dangerous; you may perforate it. (3) Insufflating air is undesirable, because escaping air mimics successful decompression. (4) Don't pass a sigmoidoscope more than 5 cm without seeing where you are going. (5) Don't use too much force[md]you may push it through his colon. (6) Wear suitable clothes and shoes, because a huge quantity of flatus and fluid will rush out.

If you see any discoloration through the sigmoidoscope, or any blood-stained fluid, or there is recurrent pain, tenderness, or shock, suspect strangulation, and do an immediate laparotomy.

If the mucosa looks normal through the sigmoidoscope, hold its distal end firmly, so that it lies immediately at the twist. Pass a large (36 Ch or about 12 mm) well-lubricated rectal (or stomach) tube along it. With a gentle rotatory movement, ease the tube past the twist into the high-pressure area of his dilated sigmoid. If you succeed, you will be rewarded by much flatus and some loose faeces. You and he will recognize that you have relieved his obstruction.

Withdraw the sigmoidoscope, taking care to to avoid displacing the tube.

Using a local anaesthetic, stitch the flatus tube to his anal margin, and leave it in place for 2 days. It may continue to discharge liquid faeces, so attach an extension tube to it, and lead this into a bucket beside his bed. If drainage stops wash out the tube. Don't leave the tube in for more than 72 hours, or it may cause pressure necrosis.

If the fluid which runs out is bloody, assume that his sigmoid has an area which is non-viable. Operate immediately. A smear of blood is not a sufficient indication for laparotomy.

If you succeed in relieving his volvulus, either refer him to have his sigmoid colon resected as soon as possible, or prepare to do it yourself. It may recur if he waits too long[md]so warn him. If you are going to resect it yourself, keep the flatus tube in, give him preparatory bowel washouts on the 3rd and 4th day, and start oral chloramphenicol or neomycin with metronidazole on the 2nd day. Give the latter rectally with the premedication (2.9). On the 5th day do a laparotomy (see below) to resect his colon, and do a transverse colostomy to protect your anastomosis. You can now do an elective operation on viable deflated gut.

If you fail to relieve his volvulus at sigmoidoscopy, operate immediately.

Fig. 10-15 SIGMOIDOSCOPY FOR SIGMOID VOLVULUS. A, the correct position for sigmoidoscopy. B, and C, two incorrect positions. The patient is not anaesthetized. The danger is that you may withdraw the tube with the sigmoidoscope, so D, E, and F, show you how to withdraw the sigmoidoscope on to its obturator and leave the flatus tube undisturbed as you do so. After Joe Shepherd, with the kind permission of the editor of Tropical Doctor.

LAPAROTOMY [s7]FOR SIGMOID VOLVULUS INDICATIONS. (1) Failure to reduce a patient's volvulus with a sigmoidoscope. (2) Signs of strangulation and gangrene.

RESUSCITATION. If necessary, resuscitate him vigorously (A 15.3). He may have lost large volumes of fluid into his sigmoid. If he has a compound volvulus, he may need 3 or even 5 units of blood.

ANAESTHESIA. You will need good abdominal relaxation (A 14.3).

EQUIPMENT. This includes a sigmoidoscope, a 36 Ch rectal or stomach tube, and two Payr's clamps or stout Kocher's clamps. A sterile spinal needle for decompressing the colon.

Have an assistant under the towels ready to insert a rectal tube up the patient's anus from below.

METHOD. Lie the patient on his back, head down, with his legs up and spread apart (LLoyd-Davies Trendelenburg position). You can sigmoidoscope him in this position, and do a laparotomy.

Pass a Foley catheter, and attach it to a sterile drainage bag. Pass a thick 36 Ch stomach tube up his anus, but don't try to pass it through the twist in his colon.

Make a generous lower left paramedian incision. You will see an enormously distended loop of colon. Gently draw it out of his abdomen.

CAUTION ! Open his tensely distended abdomen with the greatest care: you can easily nick or perforate his bloated sigmoid.

If feeling his colon and percussing it shows that it contains much gas, decompress it ''above the water line', using the spinal needle Fig. 10-9, or any 2 mm needle attached to the sucker. Pack his sigmoid off well. Push the needle through a taenia coli, and advance it longitudinally between the muscle coats for 3 cm. Then angle it inwards through the circular muscle to reach the lumen.

WHAT NEXT? [s7]AT LAPAROTOMY FOR SIGMOID VOLVULUS If the sigmoid loop is of normal colour, gently introduce the rectal tube into it. Ask your (suitably clothed) assistant to get under the drapes and pass it further up the patient's rectum. As he does this, guide it manually past the twist. The loop will deflate and allow you to untwist it. Suture the tube to his anus so that it acts as an internal splint.

Alternatively, find the pedicle and see which way it is twisted. Using both hands, try to untwist it. This will be safe provided it is not gangrenous. The loop seldom rotates by more than 360[de]. If you succeed in untwisting it, he will discharge flatus through the rectal tube. If you cannot find the pedicle and don't know which way it is twisted, twist it first one way and then the other.

What you should do next depends on your experience: (1) If you are very inexperienced, deflation alone without resection will be wiser. The problem of the patient returning to have an interval resection is a very real one[md]see above. (2) If you are very experienced, resect the viable loop and do an end-to- end anastomosis, protected by a proximal colostomy.

If you are not sure if his colon is viable or not, apply warm moist packs to it, wait 10 minutes, and then assess it by the criteria in Fig. 9-8. The large gut has a poor blood supply, so don't be too conservative, and resect if necessary.

If the loop is obviously gangrenous, assume that the area of the twist is likely to be even more unhealthy. Pack it off (it may pop like a balloon). Very cautiously decompress it by passing a spinal needle obliquely through a taenia as described above. Then untwist it.

If you are experienced, consider doing a resection and an end-to-end anastomosis protected by a transverse proximal colostomy.

If you are inexperienced: (1) If he has enough healthy gut to reach his skin, exteriorize his sigmoid colon, resect it, and do a double-barrelled colostomy (9-19, 10-16). (2) If there is not enough healthy gut for this, do Hartmann's operation.

In all these operations you will have to mobilize some of his descending colon by incising the peritoneum 2 cm lateral to it, followed by blunt dissection.

EXTERIORIZATION [s7]FOR SIGMOID VOLVULUS INDICATIONS. Sigmoid volvulus, or wounds of the sigmoid colon, in which there is enough healthy gut distally to reach the surface of the skin.

METHOD. If you think you can get the patient's sigmoid colon through a separate smaller wound, do so (see below for details as to how to do it). If not bring it out through the main wound, and make the colostomy in this.

Start by mobilizing enough of his descending colon to bring healthy gut out to the surface as a double-barrelled colostomy. You may have to go higher than you think initially. If so, ask your assistant to retract the left side of the patient's abdominal wall, so as to expose the junction of his descending and sigmoid colon. If you need more length, incise the peritoneum in his left paracolic gutter, as in B, Fig. 10-16, and carefully displace his mobilized colon medially and upwards. Draw the whole loop of sigmoid colon out of his abdomen, so that his mesocolon is transilluminated.

CAUTION ! Remember that his inferior mesenteric vessels and ureter may take a looping course near his sigmoid colon, as in C, in Fig. 10-16. Shine a laterally placed light behind the gut to reveal the mesenteric vessels, and divide them well out towards the gut wall, so that you avoid injuring his left ureter or his superior rectal vessels.

Carry the dissection back to the point where his descending colon and rectum are viable.

Bring his sigmoid colon outside his abdomen, either through the main wound or, better, through a separate small incision (see below).

If you have made this second wound, close the main one now.

Place a small crushing clamp across the lower end of his healthy colon at the point you are going to resect it. Apply a larger one immediately proximal to this.

Place two more clamps side by side where you are going to divide his recto-sigmoid junction. Divide his sigmoid through healthy gut between both sets of clamps, and remove the gangrenous loop.

If possible, make a double-barrelled colostomy by sewing the ends of the proximal and distal loops together, as in Fig. 9- 19. If you have misjudged the length of gut you need for this, proceed to do Hartmann's procedure, and close the distal end, as described below.

HARTMANN'S OPERATION [s7]FOR SIGMOID VOLVULUS etc. INDICATIONS. Sigmoid volvulus, or wounds of the sigmoid colon, in which there is not enough healthy gut distally to reach the surface of the skin.

METHOD. Mobilize enough of the patient's descending colon to bring healthy gut to the surface as a terminal colostomy, as described above.

Excise a 3 cm circle of his skin and external oblique muscle at a point in his left iliac fossa which is equidistant from his ribs, his umbilicus, and his antero-superior iliac spine. Open the jaws of a large haemostat repeatedly, to split the muscles of his abdominal wall in the direction of their fibres. When you reach the peritoneum, nick it with a scalpel, and push the haemostat right through. Put both your index fingers through the hole, and enlarge it to accept 3 fingers without compression. Push a clamp through the incision and apply it to the patient's colon at a point which is viable enough to resect.

CAUTION ! (1) Cut and clamp the mesentery of his sigmoid colon less than 5 cm from the wall of his gut, so as to avoid his ureter. Better, find and avoid his ureter first: it may lie close to his sigmoid colon, as in C, Fig. 10-16. (2) Make sure that there is enough gut to come to the surface without tension, by mobilizing his descending colon first.

From within his abdomen, apply a second clamp immediately distal to the first one. Cut between the two clamps.

Withdraw the first clamp, and gently pull his colon through the hole in his abdominal wall. Leave the clamped end of his colon on his abdominal wall for the time being. Lift his sigmoid out of the wound, and wrap a towel round it.

Fig. 10-16 OPERATIONS FOR SIGMOID VOLVULUS. A, the site for a pelvic colostomy through a small wound midway between the patient's umbilicus and his left iliac spine. B, if the proximal end of his sigmoid colon is too short, you may have to mobilize his descending colon. C, his ureter is usually on his posterior abdominal wall, but it may run close to his sigmoid, so avoid it by dividing his sigmoid mesocolon close to his gut. If there is enough healthy gut distally to reach skin level, you can excise it (D, E, and F), or you can do a Hartmann's operation. If there is not enough healthy gut distally to reach skin level, you will have to do Hartmann's operation (G, H, and I). D, healthy gut reaches his abdominal wall. E, his sigmoid exteriorized. F, the completed colostomy. G, there is not enough healthy gut distally to reach his abdominal wall. H, preparing to bring out healthy gut on to the abdominal wall. I, Hartmann's operation completed.

TO DIVIDE HIS RECTUM AND REMOVE HIS SIGMOID COLON, select a point at or near his recto-sigmoid junction, where his gut appears normal, clamp it with a crushing clump (or a large haemostat or Kocher's forceps), and apply a second one just proximal to this.

Divide his gut between these clamps (having previously withdrawn the rectal tube!).

Irrigate the operation site liberally with saline, especially the pelvis, and aspirate it dry.

TO CLOSE HIS RECTAL STUMP, start at one end with a continuous suture of 2/0 chromic catgut on a curved atraumatic needle. Run a suture through all layers and pass it around the crushing clamp, as in A to H, Fig. 9-11. Place the bites 4 mm apart, and don't pull the suture tight.

When you have reached the free end of his colon, ask your assistant to open the jaws of the clamp, and slowly pull it out. As he withdraws it, pull the loops tightly, using a haemostat and non-toothed forceps together. With the clamp removed, take another bite and tie it.

Insert a reinforcing layer of interrupted or continuous Lembert sutures, to invert the stump of his rectum (Fig. 9-11 shows the end of the colon being closed by a slightly different method).

Leave a ''2' mono- or multifilament non-absorbable suture to mark the closed end of the distal loop. This will make finding it easier, when it has to be closed.

CLOSE HIS ABDOMEN. While your assistant retracts his abdominal wall, close the space between his colostomy and his parietal peritoneum, because this is a space into which loops of gut can herniate and obstruct. Do this with 3 or more interrupted catgut sutures between his parietal peritoneum and the seromuscular layer (only) of his colon.

Apply a non-crushing clamp to the proximal gut inside his abdomen. Remove the crushing clamp from his proximal colon. Open it out and excise the crushed bowl. Pass interrupted sutures of 2/0 catgut through all coats of the cut end of his colon, and then through his skin at 4 mm intervals all round his colostomy. Place them so that there will be 1.5 cm of healthy bowel protruding beyond the skin. Better, secure the colostomy as in Fig. 9-17. Remove the non-crushing clamp holding his proximal gut inside his abdomen. Finally, put your finger through the stoma, to make sure it is not too tight.

Have a final look at his colostomy from within, to make sure his gut looks pink and healthy. Then close his abdomen, taking the precautions for secure closure (9.8) and sepsis (wash out any contamination with saline, and instil tetracycline, 6.2).

If possible, apply a colostomy bag. If not, apply vaseline

gauze, plain gauze, and a dressing pad, and tape it in place. He will probably not pass faeces for 3 days.

Finally, do an anal stretch (22.15), and insert a rectal tube for 5 cm. Suture it to his anal verge. This will prevent mucus or exudate collecting in his rectal stump.

ALTERNATIVE: [s7]TEMPORARY COLOSTOMY AS PERMANENT TREATMENT Insert a rectal tube without using a proctoscope and without intending to decompress his gut (if you happen to decompress it, consider resection 2 weeks later). Make a long left parmedian incision.

If his sigmoid is not viable, treat him as described above.

If it is viable, untwist it and decompress it through the rectal tube handled by an assistant. Insert a large Foley catheter through a small incision 50 mm above his anterior superior iliac spine. Place a purse string at the apex of his sigmoid. If necessary complete decompression by making a hole in its centre and sucking. Push the catheter through the purse string and inflate the ballon. Tie the purse string and insert a second one for safety. Pull gently on the catheter and anchor it to bring his sigmoid into contact with his lateral abdominal wall. Insert some sutures between his sigmoid near the catheter and his parietal peritoeum. To prevent internal herniation stitch his sigmid to his abdominal wall. If his distal sigmoid is very long put a few seromuscular sutures between adjacent loops.

Close his abdomen without a drain; fix the rectal tube in place and leave it for 48 hours. Attach the catheter to a collecting bottle and give him postoperative antibiotics. Remove the catheter in 10[nd]14 days. The stoma will close spontaneously in 2 weeks.

DIFFICULTIES [s7]WITH SIGMOID VOLVULUS If a LOOP OF ILEUM IS TWISTED IN WITH HIS SIGMOID COLON (COMPOUND VOLVULUS or ileosigmoid knotting, unusual), you may not be able to untwist it. Puncture and deflate it, and then clamp and resect it before you untie the knot. Anastomose his small gut end-to-end, and bring his large gut out as a temporary colostomy. If the lower limit of the gangrene on his ileum is close to his ileocaecal valve, consider closing his ileal stump and anastomosing viable small gut to his caecum.

Fig. 10-17 COMPOUND VOLVULUS complicates about 10% of cases of sigmoid volvulus in Uganda. A loop of the patient's ileum is twisted in with his sigmoid colon. The twist in his gut may be left-handed (A) or right-handed (B). If you cannot untwist it, you will have to deflate it and resect it. Don't try to untwist it if its circulation is impaired.