A total of 1070 abdominal operations were performed. Out of them, 60 patients developed wound dehiscence, giving an incidence of 5.6%.

The youngest patient was 12 days old and the oldest patient was 70 years old. The highest incidence of burst abdomen in the present study was between 41 and 50 years of age, the average age being approximately 42 years. The patients in this study were in the range of 42 ± 17.9 (ISD) years.

In our study, 81.67% of the patients were male and the remaining 18.33% females. The male : female ratio was approximately 4.5 : 1.

Figure 1

Out of 60 patients of burst abdomen, the majority had gastro-intestinal perforation (53.3%).

Figure 2

The study showed that the majority of patients had anemia as preoperative predisposing factors. Many patients had more than one predisposing factor.

Figure 3

In this study, 95 % of burst abdomen occurred after vertical midline incision. In the remaining patients, right para-median (1.6%) and lower transverse (3.4 %) incisions had been used.

Figure 4

The incidence of burst abdomen was much higher in patients operated as emergency surgery as compare to planned surgery.

The majority of burst abdomen occurred between 7^th and 10^th post-operative day, with the highest incidence on the 7^th post-operative day.

Figure 5

Many post-operative predisposing factors are responsible for burst abdomen. In this study, wound infection, cough and abdominal distention were leading factors in the majority of the cases. It is noted that most of the patients had more than one predisposing factor responsible for the development of burst abdomen.

In our study, 35 patients out of 60 had serosanguinous discharge from the wound on the 6^th or 7^th post-operative day. Fifteen patients out 60 had a swelling over the local wound site which was soft and tympanic. Six patients experienced themselves that something had given way at the local wound site and 4 patients had vomiting.

In our study, 36 patients out of 60 (60%) had complete burst involving the whole length of the wound while 24 patients out of 60 (40%) had partial burst.

In our study, 24 out of 60 patients were given conservative treatment in form of daily dressing while in 16 out of 60 patients, immediate resuturing of the wound was done and 20 patients were initially given conservative treatment and when granulation tissue developed, delayed suturing was done.

No patient had re-burst or other complications after treatment.

Total hospital stay of the patients increases because of burst abdomen. In our study, out of 60 patients, 22 had a total hospital stay between 31 and 40 days.

The mean duration of total hospital stay was 37.6 ± 16.8 (ISD) days.

Out of 60 patients, death occurred in 6 patients, giving a mortality rate of 10 %. Out of these 6 patients, 3 died because of peritonitis, 2 because of renal failure and 1 because of bronchopneumonia.

The overall incidence of burst abdomen in this series is 5.6% which is a little higher as compared to various studies mentioned in western literature. The incidence rate in Wolff’s study (1950) was 2.6% (₁), Mann (1962) found 2.72% (₂), Efron (1965) 2.2% (₃), Lehman et al. (1968) 2.5% (₄).

There appears to be an increase in the frequency of burst abdomen with advancing age. The highest incidence in the present series was between 41 and 50 years of age, the average being 42 years. According to Maingot (₅) the average age is 45 years. Wolff (₁) found that age is of some importance etiologically for disruption which was four times more common in patients above the age of 45 years than in the younger group.

The present series shows that the highest incidence of burst abdomen is between 41 and 50 years of age. This may be due to the following items:

• Those factors which pre-dispose to burst abdomen are frequently found in this age group like chronic cough due to various causes, chronic constipation and dysuria.

• Presence of anemia, hypoproteinaemia, and multiple vitamin deficiency in this age group.

• Post-operative complications like straining or cough, repeated vomiting and infection in respiratory system are more common in this age group.

The frequency rises with cancer age, i.e. 45 to 60 years. This observation coincides with Hampton’s (₆) observation in cancer cases and he considers that there is a correlation but not a cause-and-effect relationship.

The study shows that males are more commonly affected than females, i.e. in 81.67% and 18.33%, respectively. In 1934, Colp (₇) found a frequency of burst abdomen of 1.12% in males and of 0.75% in females. Hampton (₆) observed that males are three times more often affected than females (1963). Mayo and Lee (1951) also observed the same pattern of frequency of burst abdomen, i.e. males were affected more often than females. (₈)

The high incidence of burst abdomen in males may be due to excessive use of alcohol and smoking in males as compared to females which leads to chronic respiratory troubles giving rise to cough and diminished functional efficiency of the liver and other vital organs.

It is noted that the frequency of burst abdomen is related to the underlying pathological condition for which the patient was operated. In the present series, the majority of the patients were diagnosed as having a gastrointestinal perforation (53.3%).

Maingot (₅) mentioned that patients with pathologies of the biliary system or stomach are prone to developing a burst abdomen.

A higher incidence is found with operations of the gastrointestinal tract. The underlying explanation can be as follows:

• Stomach disease presents with pain, anorexia, nausea and vomiting. This dyspepsia leads to multiple deficiencies of vitamins, proteins and other substances, i.e. to marked anemia. It is observed that haemoglobin and serum protein deficiency lead to defective and delayed healing.

• Carcinoma leads to cachexia and marked anemia due to anorexia, haemorrhage and bone marrow depression.

• In biliary tract disease, the main symptoms are anorexia, dyspepsia and vomiting. Liver functions are depressed and so serum protein estimation is always low. Furthermore, a longer vertical extension of the incision is required in these patients to exclude other lesions and for wide exposure to avoid accidental complications.

In the present study it was noticed that pre-operative predisposing factors like anemia, hypoproteinemia and cough were associated with the incidence of burst abdomen. In many patients, there was more than one factor leading to the occurrence of burst abdomen.

Joergenson and Smith (₉) and Wolff (₁) noticed in their study a higher incidence of burst abdomen in patients having anemia, hypoproteinemia and vitamin deficiency.

In our study, out of 60, 34 patients had haemoglobin levels less than 10g/dl. According to Maingot (₅), at least 70% of the normal haemoglobin level is required for elective safe surgery. Haemoglobin contributes the oxygen to the regenerating granulation tissue and lower haemoglobin levels affect the wound healing.

Hypoproteinemia is one of the most important factors which delayed healing. In our study; 28 patients out of 60 had a serum protein level below 6 g/dl. For tissue repair, large amounts of amino acids are required. Amino acids help in the formation of RNA and DNA. Deficiency of these leads to poor cellular tissue, so wound strength is lost and burst abdomen is predisposed.

The importance of pre-operative cough was not emphasized previously until Hampton (₆) pointed out a higher frequency of burst abdomen in patients having pre-operative cough. In our study, 19 patients had pre-operative cough. Cough leads to increased intra-abdominal pressure and prolonged cough because of tuberculosis affects the wound healing and predisposes to burst abdomen.

In our study, 95% of burst abdomen occurred in vertical midline incisions, with the remaining patients having right para-median (1.6%) or lower transverse incisions (3.4%).

Anatomical factors which might make a vertical upper abdominal wound more likely to burst are as follows:

• Interference with blood supply as it runs transversely. The rectus abdominal muscle has a segmental blood and nerve supply.

• If incision is little more laterally, the medial part of the rectus abdominal muscle gets denervated and ultimately atrophied. This creates a weak spot in the wall and burst abdomen. This is the reason why one should not go beyond the midline.

• The rectus sheath is disturbed in vertical direction. The fibers of the sheath run transversely, so by vertical incision all of them are cut. Similarly, the anterior sheath is detached from the tendinous insertion.

• With upper abdominal incision, pain prevents chest movements thus favoring more respiratory complications and cough. Cough will increase intraabdominal pressure more in the upper part leading to tension strain in the fresh wound.

• Elastic fibers of the skin also run transversely, so they are cut by vertical incision. The strength of the wound is decreased. But as the linea alba is a weaker structure below the umbilicus, burst abdomen is more common with lower incision.

The following are the important factors enhancing the chances of burst abdomen:

• Inadequate muscle relaxation during abdominal wound closure.

• Undue tension over the stitches and increased intra-abdominal pressure due to peritoneal fluid; drainage relieves the tension.

• Forgetting to suture the peritoneal layer with the transversalis fascia as it has the tendency to get retracted.

• The majority of the abdominal surgeries are done with vertical midline incision in our hospital.

It is noted that if the operation is done in emergency, the frequency of burst abdomen is higher. As shown in the table above, 6.67% of burst abdomens occurred after planned operations and 93.33% after emergency surgery.

The explanation is as follows.

In planned operations, pre-operative physiotherapy and all blood investigations are carried out. If any infection is present, it is treated pre-operatively.

Lack of bowel preparation in emergency operations as compared to planned operations, especially for surgery of the gastrointestinal tract.

In emergencies, the underlying pathological lesion also plays an important role. In most of the emergency operations, infected lesions lead to various forms of peritonitis or wound infection. Both of them prevent wound healing.

Lack of local aseptic preparation of parts which infect the wound and increase the frequency of burst abdomen.

According to Bailey (₁₀), the maximum incidence is found on the 8^th post-operative day. In the present study, the maximum number of cases occurred from the 6^th to 10^th post-operative day, with the maximum on the 7^th postoperative day.

The explanation for the maximum incidence of burst abdomen on the 7^th post-operative day can be:

• Usually we remove stitches on the 7th or 8th post operative day. Until that time the occurrence often remains undetected. On removing the stitches, the burst becomes evident.

• We continue antibiotics for one week and on stopping them there might be relapse of infection and burst abdomen may thus occur later on.

• The patients with major abdominal surgery are in the bed having intravenous infusions up to 4 or 5 days. Then they begin to move and try to pass stools. All this increases intra-abdominal pressure. The holding-together capacity also becomes less and less until, after 10 days, stitches hardly have value.

Many post-operative factors lead to high incidence of burst abdomen. In the present study, out of 60 patients, 44 had wound infections, 27 had post-operative cough and 21 had abdominal distention. More than one factor was found in most of the patients.

Wound infection is a major post-operative cause for wound disruption. It leads to slough out of the stitches and separates the rectus sheath. Wound infection is more common in emergency operations and patients presenting with peritonitis.

Post-operative cough also leads to high frequency of burst abdomen. It usually occurs because of respiratory tract infection, possibly post-anesthetic, leading to increased intra-abdominal pressure. Thus, tension over the freshly sutured wound can cause burst. In the same way, post-operative abdominal distention also increases tension on the freshly stitched wound leading to burst.

Vomiting after abdominal surgery leads to vigorous tension on the suture line and breaks up the stitches leading to burst abdomen. Uremia is also a factor which disturbs wound healing and leads to burst abdomen. Bowel leakage leads to peritonitis and infects the wound.

In the post-operative period, electrolyte imbalance and ascites also have an effect on wound healing and tension on wound contributes to the occurrence of burst abdomen.

In our study, 35 out of 60 patients had serosanguinous discharge from the wound. This is almost pathognomonic of dehiscence. It is an indicator of sheath gap and of burst abdomen.

Fifteen patients had a swelling over the wound site which was a soft and tympanitic boggy swelling that distends the wound. It indicates that a knuckle of gut has burst through all the layers of the abdominal wall and lies under the skin incision.

Six patients experienced themselves that there is something giving way at the wound site. This occurs after excessive strain like excessive cough or vomiting. Four patients had unexplained vomiting which led to the diagnosis of burst abdomen.

Maingot (₅) observed in his study that most of the patients had serosanguinous discharge from the wound. Some also had swelling at the wound site and some had unexplained vomiting.

Thirty-six patients out of 60 had complete burst abdomen in our study, i.e. the whole wound was burst. This usually occurred in patients having severe peritonitis in which the whole sheath was sloughed out and in patients who had severe strain.

Twenty-four patients had partial burst abdomen. Those having wound infections that affect a small area had partial burst abdomen.

Wolff (₁) observed in his study that the majority of patients had complete burst abdomen.

In our study, 24 out of 60 patients were treated conservatively. Those patients who were not fit for surgery were treated conservatively in form of daily dressings. Day by day healthy granulation tissue developed and the wound healed by secondary intention.

Sixteen out of 60 patients were treated by immediate resuturing of the wound. Resuturing was done as mass closure with Ethilon no. 1.

Twenty patients out of 60 were treated initially with conservative treatment and then, when granulation tissue developed, delayed suturing was performed.

Maingot (₅) described that patients treated with conservative treatment had prolonged hospitalization and more morbidity as compared to patients treated by immediate resuturing.

Because of burst abdomen, the total duration of hospital stay increases and patients are discharged after prolonged hospitalization. Patients treated with conservative treatment or with delayed suturing had prolonged hospitalization.

Mortality following burst abdomen varies considerably in different reported studies. It is reported as low as 11% by Wolff (₁) and as high as 40% by Hartzell and Winfield (11). Hampton (₆) observed the mortality rate to be 23% in 1963. In the present study the mortality rate is 10%.

The mortality rate is steadily decreasing as years are passing on. In the last 30 years the rate has decreased to half of the previous one. The reasons for such a decrease can be as follows:

• Early recognition of the burst abdomen and skillful choosing of those cases that should be treated by immediate resuturing, those that should be treated by delayed resuturing and those in whom non-operative treatment should be employed.

• Pre-operative preparation of the patient by correcting hypoproteinemia, anemia, vitamins deficiency and also physiotherapy.

• Advance in general anesthesia where post-anesthetic complications are lowered and at the time of operation good muscle relaxation is permitted to the operating surgeon.

• Easily availability of blood and its free use during and after operation.

• Rapid advance and introduction of better broad-spectrum antibiotics in general use

• whereby controlling the severe infections.

• Early ambulance of the operative patient and employment of post-operative physiotherapy.

• Better understanding of surgical physiology and pathology of burst abdomen.

Still this mortality can be greatly reduced by thorough examination of patients and their selection for operation, pre-operative preparation, skillful and aseptic surgery, better post-operative care and, lastly, by keeping this complication in mind.