Acute perforated appendicitis in adults: Management and complications in Lagos, Nigeria.

Background: Acute perforation of the appendix is one of the complications of appendicitis that is associated with increased morbidity and mortality and hence regarded as a surgical emergency. Risk factors for perforated appencidicits include extremes of age, male sex, pregnancy, immunosuppression, comorbid medical conditions and previous abdominal surgery.
Objectives: This study focuses on the pattern of presentation, risk factors, morbidity and mortality of patients managed for perforated appendicitis in our centre. Subjects and
Methods: We conducted a seven-year retrospective review of consecutive adult patients who had surgery for perforated appendicitis in our centre.
Results: The perforation rate in the study was 28.5%. The peak age of presentation was between 21-30 years. Forty-two (71.1%) of the patients under study were males. Only 3 (5.1%) of the cohorts had history of recurrent abdominal pain. Majority of the patients were in the American Society of Anesthesiologists (ASA) II (44.1%) and III (42.4%) categories. Surgical site infections (SSI) (18.6%), wound dehiscence (15.2%) and pelvic abscess (13.5%) were the most common complications. The Incidence of SSI was found to correlate with male gender, (P = 0.041), co-morbidity (P = 0.037) and ASA score (0.03) at 95% confidence interval. Routine use of intraperitoneal drain after surgery for perforated appendicitis did not appear to reduce the incidence of pelvic abscess. No mortality in the studied population.
Conclusion: Appendiceal perforation was more common in male patients with first episode of acute appendicitis. Previous abdominal surgery and comorbid medical conditions were of lesser risk factors for appendiceal perforation in our patients. Surgical site infection was the commonest complication after surgery.

INTRODUCTION

Acute appendicitis and its complications are leading causes of acute abdomen and indications for emergency surgical intervention in clinical practice.

In clinical terms, acute appendicitis can be described as simple or complicated. Complicated appendicitis includes appendix mass, appendix abscess, and perforated appendicitis. Most complicated appendicitis started de novo as simple appendicitis raising the notion that it is a disease in evolution that has become of clinical importance due to delayed or missed diagnosis. Grossly, simple appendicitis is of two major forms: obstructive and catarrhal appendicitis. Acute appendicitis in adults is often obstructive in type and sequel to some form of luminal obstruction by fecaliths, lymphoid tissues, or rarely foreign bodies.[1] Extrinsic causes of luminal obstruction of the appendix include periappendiceal bands. Anatomically, appendix is a blind-ending structure. A closed-loop obstruction of its lumen in severe cases result in inflammation and transmural necrosis which eventually lead to perforation and discharge of the luminal contents (pus and fecaliths) and peritonitis. A prospective study by Narsule et al.[2] on 202 children undergoing appendicectomy revealed a linear relationship between the duration of symptoms (onset to surgery) and risk of perforation. In their study, no perforation was recorded in children with abdominal pain of <12 h duration. The perforation rate rose in a linear fashion from 10% by 18 h to 44% by 36 h. If symptoms were present for more than 2 days, the risk of perforation was >40%. In contrary, Bickell et al.[3] in an earlier retrospective study of 219 adults with appendicitis had documented a minimal perforation risk in the first 36 h of symptom onset and remains at 5% thereafter. However, a study has shown that in many patients treated with antibiotics, appendicitis symptoms may resolve without ensuing perforation; hence, medical treatment with antibiotics has been proposed in a selected group of patients with uncomplicated appendicitis.[4]

Sequelae of appendiceal perforation have some important economic consequences and are associated with increased length of hospital stay, morbidity, and mortality even with treatment.[5] These factors are important considerations in developing countries where access to health care and resources are limited with attendant delay in diagnosis and treatment.

Management options for perforated appendicitis range from percutaneous drainage to laparoscopic and open appendectomy with drainage. To the best of our knowledge, few studies have focused on the management outcome of patients with perforated appendicitis in our environment. This study aimed to determine the pattern of presentation, risk factors, and incidence of postoperative complications and mortality in patients who had surgery for perforated appendicitis in our institution.

METHODOLOGY

A 7-year retrospective review of medical records of patients aged 16 years and above who had surgery for appendiceal perforation between July 2010 and June 2017 in our hospital was carried out.

Approval for the study was obtained from the Lagos University Teaching Hospital's Health Research Ethics Committee.

Patients’ demographic characteristics, clinical presentation, laboratory parameters, radiological features, surgical intervention time, and postoperative complications were entered into a structured pro forma for analysis. Data analysis was done using IBM SPSS statistics for Windows, Version 23 (IBM Corp., Armonk, NY, USA). Results of the analysis were expressed in tables as simple percentages. Relationships between patients’ gender, medical comorbidities, duration of symptoms, preoperative American Society of Anesthesiologists (ASA) score, and incidence and type of postoperative complications were tested by Chi-square tests. Statistical significance was set at P < 0.05.

RESULTS

There were 224 cases of acute appendicitis managed during this period. Sixty-four patients had appendiceal perforation, giving the perforation rate of 28.5%. Of a total of 64 patients who had surgery for acute perforated appendicitis, 5 were excluded from further data analysis due to incomplete records.

Of 59 patients under review, there were 42 (71.1%) males and 17 (28.8%) females, giving a ratio of 2.5–1. The mean age at presentation was 29.98 ± 2.08 (range: 16–70) years and median was 26 years. The peak age of presentation was between 21 and 30 years, accounting for 44.1% of all cases [Table 1].

Table 1

Age and sex distribution of patients with perforated appendicitis (n=59)

Age (years)	Male	Percentage (%)	Female	Percentage (%)	Frequency (subtotal) (%)
≤20	12	20.3	2	3.4	14 (23.7)
21-30	15	25.4	11	18.6	26 (44.1)
31-40	8	13.5	3	5.1	11 (18.6)
41-50	3	5.1	0	0	3 (5.1)
51-60	3	5.1	1	1.7	4 (6.8)
>60	1	1.7	0	0	1 (1.7)
Total	42	71.1	17	28.9	59 (100.0)

The mean duration for onset of abdominal pain before presentation was 4.5 ± 3.42 days (range: 0.74–14 days). Abdominal pain was present in all patients. Fifty-two (88.1%) patients reported initial periumbilical pain before it became generalized. Nausea and vomiting were present in 50 (84.7%) patients and anorexia in 33 (55.9%) patients. Five (8.4%) of the patients had comorbid medical conditions and one was pregnant [Table 2]. Total white cell count record was retrieved in 53 of 59 patients [Table 2]. Of these, leukocytosis of >10,000/mm3 was present in 34 (64.2%) of patients. Only 23 patients had preoperative abdominal/chest X-ray. The predominant finding among these patients was that of small bowel obstruction/ileus in 11 (47.8%) patients. Only 3 (13%) of 23 patients evaluated with abdominal/chest X-ray had radiological evidence of pneumoperitoneum. Abdominal ultrasound findings were retrieved in 38 (64.4%) patients. The major finding on abdominal ultrasound among these patients was periappendiceal fluid collection in 17 (44.7%) cases.

Table 2

Clinical symptoms,risk factors and total white cell count in acute perforated appendicitis (n=59)

Nature of symptoms (n=59)	Frequency of symptoms out of 59 patients (%)
Abdominal pain migration	52 (88.1)
Anorexia	33 (55.9)
Nausea and vomiting	50 (84.7)
Fever	37 (62.7)
Dyspepsia	4 (6.8)
Diarrhea	15 (25.4)
Constipation	19 (32.2)
History of similar attack in the past	3 (5.1)
Previous abdominal surgery	5 (8.5)
Comorbidities (diabetes and hypertension)	5 (8.4)
Pregnancy	1 (1.7)
Total white blood cell count/mm3 (n=53)	Frequency (%)
<4000	4 (7.5)
4001-10,000	15 (28.3)
>10,000	34 (64.2)

Using the surgical risk classification of the ASA, the predominant ASA groups were in classes II and III which accounted for 44.1% and 42.4% of cases, respectively [Table 3]. The range of hospital stay was 5–56 days [Table 3].

Table 3

Preoperative American Society of Anesthesiologists (ASA) grade and hospital stay after surgery (n=59)

ASA grade	Frequency (patients) (%)
I	6 (10.2)
II	26 (44.1)
III	25 (42.4)
IV	2 (3.4)
Total	59 (100)
Hospital stay (days)	Frequency (days) (%)
0-7	9 (15.3)
8-14	33 (55.9)
15-21	10 (16.9)
22-28	3 (5.1)
>28	4 (6.8)
Total	59 (100)

ASA=American Society of Anesthesiologists

Surgical site infections (SSIs), wound dehiscence, and pelvic abscess were the most common complications at 18.3%, 15.2%, and 13.5%, respectively [Table 4]. There was no mortality in our review.

Table 4

Postoperative complications (n=59)

Complication	Frequency (%)
Surgical site infections	11 (18.6)
Wound dehiscence	9 (15.2)
Pelvic abscess	8 (13.5)
Postoperative pyrexia	5 (8.5)
Chest infection	2 (3.3)
Organic brain dysfunction	1 (1.6)

Univariate analysis using Chi-square test at 95% confidence interval and significant P < 0.05 showed that overall complication rate is significantly related to the ASA score (χ2 = 11.22; P < 0.05). There was also a statistically significant relationship between SSI and male sex (P = 0.041), comorbidity (P = 0.037), and ASA (0.03) at 95% confidence interval. However, there was no statistically significant association between SSI and age (age group), previous attacks, and total white blood cell count at presentation.

DISCUSSION

Acute appendicitis is a leading cause of acute abdomen requiring surgery in Nigeria. A prospective study of 276 patients at Ilorin revealed that acute appendicitis was the most common cause of acute abdomen and was responsible for 30.3% of all cases seen within the study period.[6] However, the incidence of perforation (perforation rate) in acute appendicitis varies widely; a perforation rate between 4.4 and 39% has been reported in the West African Subregion.[78910]

A retrospective study by Njoku et al.[7] on 655 appendicectomies revealed 29 cases of perforation giving a perforation rate of 4.4%. Adeyanju and Adebiyi[8] reported perforation rate of 13 (7.2%) of 180 appendicectomies. Another retrospective study by Edino et al.[9] on 142 appendicectomies reported 33 cases of appendiceal perforation with a perforation rate of 23.2%. Yeboa[10] in Ghana found 249 cases of appendiceal perforation in 638 appendicectomies with a perforation rate of 39%. In our study, the perforation rate was 28.5%. This is far higher than observed by some researchers in Nigeria and less than the quoted figure from Ghana.[78910] This difference may reflect varying pattern of referral and these studies are retrospective.

Delay in surgical intervention has been associated with increased rate of perforation from 3% in patients operated within 24 h of presentation to 31% in patients operated at 36 h.[11]

The incidence of perforated appendicitis is higher in the extreme of ages.[251213] Ahmad et al.[12] reported 46.15% in the first decade of life and 56.61% in the elderly patients presenting with appendicitis. Documented risk factors for appendiceal perforation in elderly include male sex, fever ≥38°C, immune compromise (diabetes and steroids use) anorexia, and duration of abdominal pain before presentation.[5] In children, nonspecific nature of abdominal pain of acute appendicitis leads to delayed presentation. In addition, there is a higher rate of progression of appendicitis in children due to lack of well-developed omentum and abdominal fat to contain inflammatory process.[2414]

The mean age for perforated appendicitis in our study was 29.98 ± 2.08 years and the peak age at presentation was found in the third decade of life. Of 59 patients, 26 (44.1%) were between 21 and 30 years. An earlier retrospective review of 250 cases of appendicitis from our center had documented the mean age of 25.7 ± 0.103 years and the peak age in the third decade of life accounting for 42.8% of cases.[15] In general and within the peak age group, we found a higher incidence of perforated appendicitis in our male patients. The exact reason why perforated appendicitis is more common in males is not clear, but similar association has been found in many studies.[161718] In our opinion, a higher incidence of appendicitis in male patients as documented in most series may explain why its complication is also more frequent in the male population.

Comorbid medical conditions and immune suppressive states are known risk factors for appendiceal perforation. Only 5 (8.4%) of our patients had comorbid medical conditions: Four were hypertensive and one was diabetic.

Abdominal pain was present in 100% of patients, with 52 (88.1%) patients reporting classical abdominal pain migration from localized periumbilical to generalized abdominal pain. Leading associated symptoms were nausea and vomiting in 84.7% of patients and anorexia in 55.9%. Similar findings were found by Ohene-Yeboah and Togbe in Ghana and Fashina et al in Nigeria.[1015]

Leukocytosis with polymorphonuclear predominance is helpful in the diagnosis of acute appendicitis. While a study had documented leukocytosis of >10,000 cells/mm3 in 80%–85% of patients with acute appendicitis,[19] a previous study in our institution had shown that the leukocytosis is not a feature of acute appendicitis in our environment. Fashina et al.[15] reported a mean white cell count of 8538 ± 4166 mm3 in acute appendicitis. However, in appendiceal perforation, leukocytosis is marked. We found leukocytosis of >10,000/ mm3 in 33 (55.9%) patients reviewed.

Electrolyte abnormalities are commonly encountered in patients with acute abdomen due to fluid loss. In addition, many of these patients are on nil per os while a definitive diagnosis is being sought and in preparation for surgery. We retrieved electrolyte panel results in 52 of 59 patients. The predominant electrolyte abnormality was hypokalemia (serum potassium <3.5 mmol/l) which was found in 19 (36.5%) of 52 patients. This was corrected before surgery.

Plain abdominal/chest X-ray and abdominal ultrasound are common first-line radiological investigations for suspected acute abdomen in our accident and emergency.

This study confirmed the opinion that pneumoperitoneum due to appendiceal perforation is not a common occurrence in plain abdominal/chest X-rays, and most cases reported in the literature were in the form of case reports/case series.[2021] Some larger retrospective studies have reported findings of pneumoperitoneum in 5%–8% of gastrointestinal perforations due to perforated appendicitis.[2223] In 23 patients evaluated with abdominal/chest X-ray, we found the frequency of pneumoperitoneum in 3 (13%) cases. A higher value obtained in this study may be attributed to the estimation of frequency of pneumoperitoneum in cohorts of patients under review, rather than the etiology of pneumoperitoneum in acute abdomen which was evaluated in most studies.[2223] The clinical diagnosis and indications for surgery in most of our patients were based mainly on the history and clinical signs of peritonitis. Positive radiological signs of perforation such as pneumoperitoneum were added reinforcement to our diagnosis and our decision to operate.

In the preoperative anesthetic assessment of our patients using the ASA physical status classification score, majority of the patients were in ASA II (44.1%) and III (42.4%) categories. Only two patients in the review which showed signs of severe toxicity and peritonitis as were in ASA IV category. Ours is a referral center and is a common practice for referring institutions to commence antibiotics treatment for patients with acute abdominal condition. This may have limited severity of endotoxemia and systemic sepsis at presentation. This is coupled with the fact that most of the patients in this study are young with low rate of comorbid medical conditions. About 86.4% of our patients were <40 years.

Definitive treatment of acute appendicitis and its complications is accomplished by the removal of appendix and other infected foci, drainage of abscess, irrigation of the abdomen with saline, and insertion of peritoneal drain as indicated. This can be achieved via open or laparoscopic surgery. However, in recent times, some authorities have advised selective antibiotic use for perforated appendicitis and those due to phlegmon followed by interval appendectomy in Children.[24] This approach is still controversial due to its high failure rate and may not be applicable to adult scenarios. Our treatment of choice for acute simple and complicated appendicitis is appendicectomy. We use Lanz incision where the peritoneal signs are localized or a laparotomy in case of generalized peritonitis.

SSIs (18.6%), wound dehiscence (15.2%), and pelvic abscess (13.5%) were the common complications we encountered in this study. In our practice, we routinely leave a peritoneal drain for all patients after exploratory laparotomy for viscus perforation and remove drain when it is no longer active (<50 ml/day). We also administer broad-spectrum antibiotics from admission for about 1 week after surgery. There are some concerns regarding the benefit of this approach as it has not been shown to reduce post-op septic complications. Levin and Walter[25] reported that perforated appendicitis is a single predisposing factor for the development of postappendectomy intra-abdominal abscess. They found that technique of stump closure, routine saline peritoneal lavage, and drain placement did not decrease the risk of intra-abdominal abscess in perforated and nonperforated appendicitis. In this study, 8 (13.5%) of the patients had pelvic abscess, and in our experience, routine use of peritoneal drain after surgery for perforated appendicitis did not appear to reduce the incidence of pelvic abscess. A recent Cochrane review has shown that the effect of abdominal drainage on prevention of intraperitoneal abscess or wound infection after open appendectomy is uncertain for patients with complicated appendicitis.[26]

The overall complication rate in our study was 43.1%. However, some patients had more than one type of complications. Preoperative ASA score was found to be associated with the incidence of complications after surgery for perforated appendicitis (χ2 = 11.22; P < 0.05). The study also showed some association between incidence of SSI and male gender (P = 0.041), comorbidity (P = 0.037), and ASA (0.03) at 95% confidence interval. However, there is no statistically significant association between SSI and age (age group), previous attacks, total white blood cell count at presentation, and time to surgical intervention.

CONCLUSION

Perforated appendicitis is a common complication of acute appendicitis occurring in a young population in our environment. Significant risk factors for appendiceal perforation in this study were first episode of abdominal pain and male sex. A history of recurrent acute appendicitis predating perforation was found in minority of our patients. In addition, previous abdominal surgery and comorbid medical conditions were less contributing factors in our patients. SSI was the most common complication after surgery. Routine use of intraperitoneal drain had little effect on the incidence of pelvic abscess. The overall prognosis is good with early surgical intervention.

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Nil.

Conflicts of interest

There are no conflicts of interest.