Abdominal Wall Dehiscence
Moshe Schein
The gut bursts out either because you did not close the tummy properly or it has no place inside . . .
When rounding on your patient, who 5 days ago had a laparotomy for intes- tinal obstruction, you find his wound dressings soaked in some clear-pinkish fluid.
“Change the dressings more frequently”,you mutter to the intern.A day later,during lunch, you are paged by the head nurse on the floor:“Doctor, Mr. Hirsch’s intestines are spread all around his bed. Please come and help…!” How embarrassing.
Definitions
Abdominal dehiscence is either complete or partial, the latter being much more common.
Partial(covert, latent) dehiscence is a separation of the fascial edges of the wound without evisceration or full exposure of the underlying viscera. It presents usually a few days after the operation with some sero-sanguinous peritoneal fluid seeping through the wound. When the skin edges are separated or if, as commonly occurs, wound infection is present, you may see the exposed fascia, loose fascial sutures, and occasionally a fibrin-covered loop of intestine
Completedehiscence is full a separation of the fascia and skin. Loops of intestine – if not glued in place by adhesions – commonly eviscerate “all over the place”.
Etiology
Multiple local, mechanical and systemic factors contribute to abdominal wound dehiscence: ileus, distention, deep wound infection, pulmonary disease, hemodynamic instability, ostomies in the wound, age >65, hypoalbuminemia, systemic infection, obesity, uremia, malignancy, ascites, corticosteroid use, and hypertension. These are factors that cause poor tissue healing or increased intra- abdominal pressure, and you’ll find a few of these in any patient who suffers a
47
dehiscence. Dehiscence, be it complete or partial, is associated with a significant mortality rate.The prevailing perception is that dehiscence is only a marker for these underlying local and systemic factors, and thus is not directly responsible for the associated morbidity and mortality.However, the way dehiscence is managed also affects on the outcome, as you’ll see below.
How to Prevent Dehiscence?
You can prevent dehiscence by:
Choosing a “correct” incision (> Chap. 10)
“Correctly” closing the abdomen (> Chap. 38)
Not closing abdomens that should be left open (> Chaps. 36 and 46)
Generally, it appears that vertical incisions – especially the midline – are associated with a greater incidence of dehiscence than transverse incisions. In mechanical terms, three main causes for dehiscence exist: the suture breaks, the knot slips, or the tissue breaks(i.e. the suture cuts through the tissues). The last mentioned is the dominant one. Please re-read > Chap. 38 to ingrain in your brain how dehiscence can be prevented by correct abdominal closure.And remember that abdomens that are very likely to burst could be left open as discussed elsewhere in this book (> Chaps. 36 and 46).
Note: to avoid intra-abdominal hypertension and subsequent fascial dehi- scence you can leave the fascia unsutured but close the skin. This is what we do occasionally in high-risk situations, after, say, laparotomies for mesenteric ischemia or intestinal obstruction within a complex incisional hernia. We suture the sub- cutaneous layer with heavy absorbable suture and the skin with Nylon 2-0, which is left in situ for at least 2 weeks. A planned hernia is much better tolerated than fascial dehiscence!
Treatment
“Leading” surgical texts advocate an immediate surgical closure of the dehis- cence.For example,Schwartz’s textbook recommends that “If the patient can tolerate the procedure,a secondary operative procedure is indicated”.What kind of a patient
“cannot tolerate the procedure” is not stated. The guidelines published by the American College of Surgeons state that if “dehiscence is significant, an immediate operative re-closure is preferred”. A text devoted to complications in surgery sug- gests that “when a dressing is found soaked in salmon-pink fluid… a fascial defect or a loop of bowel palpated just below the skin… a binder must be applied and the 412 Moshe Schein
patient sent promptly to the operating room”. In addition,“failure to repair dehis- cence results in evisceration in most cases… re-closure, in contrast is strikingly successful”. Another recent text on re-operative general surgery emphasizes that
“abdominal wound dehiscence is clearly a surgical emergency” requiring fascial re-closure (> Fig. 47.1).
Managed according to the above recommendations the patient is taken to the operating room where the abdomen is re-sutured with “retention sutures” (see
> Chap. 38). So why is the mortality so high? Many still think that “most deaths
associated with dehiscence today are the result of ongoing primary disease rather than being a direct result of this complication”. There is a large body of data, how- ever, to suggest that such hypothesis is not true. Instead, it appears that the “re- commended” treatment of the dehiscence, re-closure, plays a significant role in the associated M & M (morbidity and mortality).
We believe that that forcing the distended intestines back into a cavity of limited size may kill the patient. The fatal factor leading to the high mortality rate associated with abdominal wound dehiscence is not the dehiscence itself but the emergency procedure to correct it, which produces intra-abdominal hyper- tension, which in turn adversely affects cardiovascular, respiratory, renal, and intestinal function, leading to multi-organ dysfunction and eventually to death.
(> Chap. 36).
413 47 Abdominal Wall Dehiscence
Fig. 47.1. “Doc, pull harder!”
Recommended Approach to Dehiscence
Instead of routinely “pushing back” the bulging viscera into the limited space of the peritoneal cavity, be selective, using the following rationale:
Complete dehiscence mandates an operation to reduce the eviscerated ab- dominal contents. You cannot leave the intestine hanging outside the bed. You may attempt a re-closure of the fascia when a faulty closure technique or a broken suture is the cause of the dehiscence and local circumstances permit – but only if the facial edges can be approximated without excessive tension. If this is not the case you should leave the abdomen temporarily open,using one of the temporary abdominal closure (TAC) methods described in > Chap. 46. We avoid re-closure also when the abdominal wall is frail or if the cause of the evisceration – persistent intra- abdominal infection – is still present. What is the use of re-suturing the abdomen if the factors causing the evisceration in the first place are still present?
Partial dehiscence may be managed conservatively.Many surgeons feel com- pelled to take the patient to the operating room and re-suture the fascia. But what’s the rush? In our experience this is not only unnecessary but may even complicate matters. The natural course of a partially dehisced wound is to heal by granulation and scarring with or without the formation of an incisional hernia.Re-suturing such a friable wound in a compromised patient entails the additive risks of anesthesia and abdominal re-entry while not preventing the eventual hernia. The latter, if sympto- matic, can be repaired electively at a later stage. If the bowel were partially exposed we would approximate the skin to cover it. Otherwise, the wound is managed as any open wound (> Chap. 49) until healed.
In summary: Regard dehiscence as a symptom rather than a disease. Operate for complete dehiscence with evisceration; re-suture fascia or use a TAC device selectively. Most cases of partial dehiscence are best treated conservatively.
Commonly, dehiscence of the abdominal wound represents a spontaneous decompression of intra-abdominal hypertension, and thus could be defined as a
“beneficial” complication.
414 Moshe Schein
