Incisional hernias

These range from a small bulge at the site of a stab drain, to the huge multiloculated swelling that follows the breakdown of a major incision, usually a lower median one. Incisional hernias are more likely to occur when a patient's wound has been poorly sutured, particularly with catgut (9.8), or has become infected, or if he has a chronic cough, constipation, or some serious systemic disease, such as advanced malignancy, or a typhoid perforation of his gut. Hernias are much less common if you follow the methods of closing the abdominal wall in Section 9.8.

He presents with a lump, or a bulge, under the scar of a previous abdominal incision. If he allows it to grow large, his gut may only be covered by peritoneum and skin, which may be paper-thin and adherent to his gut. If it is very large and long- standing, his rectus muscles may have separated widely round it, so that you are quite unable to reduce it. It may reach from one of his flanks to the other, from his xiphoid to his symphysis pubis, and contain almost any of his abdominal organs.

In the developing world the commonest incisional hernias follow lower midline incisions for Caesarean section. Fortunately, they are not too difficult to repair. Other incisional hernias may be very difficult. Although recurrence is common, strangulation is not, so don't operate on these other hernias unless you have to, especially if a hernia is large, and above a patient's umbilicus. Fortunately, he unlikely to be fat, because this makes repair even more difficult.

Fig. 14-23 AN INCISIONAL HERNIA. A, the hernia with the ellipse of swelling to be removed. B, removing redundant tissue over it. C, dissecting flaps of stretched aponeurotic tissue from the sac. D, opening the hernial sac at its neck. E, freeing adherent contents of the sac. F, closing the peritoneum. G, and H, overlapping the aponeurotic layer. After Rob C and Smith R, ''Operative Surgery: Part I: Abdomen, Rectum and Anus', (2nd edn 1969), p.212 Figs. 1 to 9. Butterworths, with kind permission.

INCISIONAL HERNIAS EXAMINATION. Lay the patient down, and put your hand through the weakened area in his abdominal wall to feel the size and shape of his hernia. It may be elliptical, or irregular, and he may have more than one. Ask him to raise his head and shoulders off the couch without using his arms. This will fill the sac and show you its true size.

If the hernia followed Caesarean Section, ask the patient to contract her abdominal muscles. If her recti become taut, almost meet in the midline, and grip your fingers, you should be able to repair her hernia without too much difficulty.

MANAGEMENT. Don't operate on difficult incisional hernias if you can avoid it.

If a patient's hernia is very large, and long-standing, and he is obese, refer him. Surgery will be very difficult; advise him to wear a corset.

If you have to operate yourself, prepare for a difficult procedure.

If his hernia is above his umbilicus, it will be harder to repair than one below it, because his ribs will prevent you bringing the edges of the opening together. Refer him.

If he is elderly, sick, or sedentary, and his hernia is completely reducible, consider fitting him with an abdominal belt or corset. This will be dangerous if you cannot reduce it completely. A corset is not ideal, but he may tolerate it. If necessary, improvise one.

If his hernia is not too large, say 8[mu]4 cm, is in his lower abdomen, and you can use standard methods, consider operating. If it is in his upper abdomen, it should be smaller than this before you decide to operate.

PREPARATION. If he is obese, encourage him to lose weight. He may have infected intertrigo, so prepare his skin with special care.

ANAESTHESIA. You will need good relaxation (A 14.1), so use subarachnoid (spinal) anaesthesia, or general anaesthesia with relaxants. While his abdomen is relaxed under anaesthesia, feel the margins of the defect carefully.

LOWER MIDLINE HERNIA [s7]PARTICULARLY FOLLOWING CAESAREAN SECTION INCISION. Under general, low subarachnoid, or epidural anaesthesia, make an elliptical incision in the long axis of the patient's hernia, wide enough to include a third to a half of her bulging skin, and extending 4 cm beyond the defect at each end. Design the ellipse so as to remove the original scar and to produce a new one, without redundant skin or a tense suture line.

Define the margins of the defect, and free her adherent small gut and omentum from the fundus and sides of the sac. Use sharp dissection to free her peritoneum, and her anterior rectus sheath, from the fleshy fibres of her rectus muscles, which are sandwiched between them.

Control bleeding, which may be troublesome, and try to repair her lower abdominal wall, layer by layer. Before starting the repair insert 6 or 8 tension sutures of No. 1 monofilament.

Make flaps at either side, so that her skin and subcutaneous tissue (if there is any) are undermined for at least 4 cm (not shown in the Fig. 14-23). Try to find a plane of cleavage between her peritoneum and her skin, without button- holing either of them. Undermining will be easier if you insert 4 or 5 interrupted sutures near the skin edge, and ask your assistant to exert traction on them, while you dissect them free from the underlying sac.

If freeing the ellipse of skin from her underlying hernial sac is difficult, because her hernia is subcutaneous in the centre of the sac, leave the ellipse attached to the sac. Proceed to raise flaps of scar tissue as described below, and excise the ellipse and part of the sac together. Control bleeding carefully.

Raise flaps of aponeurotic scar tissue from the covering of the sac on either side (C).

The neck of the sac will probably be diffuse, and not easy to define. Open it between haemostats near its neck, as for a laparotomy (D), and incise her peritoneum far enough to see if there are adherent loops of gut. Free these adhesions (E), and return her gut and omentum to her abdomen.

If you cannot easily free her gut and omentum from the fundus of the sac, leave them attached to it; free it from her skin, if you have not already done so, and fold the sac inwards into her abdomen.

Excise the redundant part of the sac, and suture its edges with continuous catgut (F).

Dissect and trim the scarred flaps of aponeurosis, to expose the edges of her rectus muscles on either side. Trim these flaps away to leave a broad strip on one side, and a narrow strip on the other. Overlap these strips so as to bring her rectus muscles to the midline (G). Using interrupted No. 1 monofilament, make mattress sutures on one side, and simple ones on the other. Take good-sized bites, and don't tie the sutures so tightly that they strangle her tissues. In this way, a double-thickness layer of fibro-fascia will replace her linea alba.

Insert a few catgut sutures between her superficial and her deep fascia, so as to obliterate any potential spaces where blood might collect.

If you can use suction drainage, insert a multiholed catheter through a stab wound, let it lie under the flap, and attach it to the suction. Or insert two corrugated drains subcutaneously, and bring them out through stab wounds.

Suture her skin edges, apply a firm pressure dressing, and don't disturb it until the stitches are to be removed. A many- tailed bandage will provide physical and psychological support.

Alternatively, don't open, or remove, the hernial sac. Instead, dissect off the skin and scar tissue, pleat and infold the sac, and bring the skin edges together.

CAUTION ! If she develops a cough postoperatively, it is likely to disrupt the repair. Teach her to support the wound as she coughs by pressing her hands to the sides of her abdomen.

DIFFICULTIES [s7]WITH INCISIONAL HERNIAS If she has such a large incisional hernia that her PREGNANT UTERUS COMES THROUGH THE INCISION and falls into her lap, consider doing the repair immediately after delivery, and tying her tubes.

If she has a RECURRENT incisional hernia, repair is likely to be very difficult indeed. If she is comfortable in a corset treat her nonoperatively. Otherwise, refer her.