NEGATIVE APPENDECTOMY

FREQUENCY AT A TEACHING HOSPITAL

Abstract

Acute appendicitis is the most common surgical emergency. Despite advances
in diagnostic techniques, an accurate pre-operative diagnosis may still pose a challenge to
the clinicians. Therefore, even today we are facing a high rate of negative appendectomy.
The current study explores this aspect of a common and important disease. Objectives: To
know the percentage of negative operative findings in acute appendicitis in our hospital that
drains wide area of population from lower socioeconomic strata. Patients and methods: This
prospective cross-sectional study was conducted at Department of Surgery, Lady Reading
Hospital, Peshawar within two years from 1-1-2009 to 31-12-2010. This study included 673
cases undergoing appendectomy. All the patients operated for clinical diagnosis of acute
appendicitis over the study period were included. Their history, clinical features, and results
of investigations were noted. Gross examination of intact appendix specimen, and on-table
cross sectional inspection of appendix was made; and were correlated with histopathological
findings (as gold standard). Results: The study included 673 patients. There were 478 males
(70%), and highest number of patients was in second decade of life. On gross examination,
545 (81%) appendices were swollen, 531 (79%) were reddened due to inflammation; 63 (9.4%)
were gangrenous; and 50 (7.5%) had perforated; while in 128 patients (19%) the appendix was
normal looking with shiny surface. Fibrino-purulent exudate in the peri-appendeceal region
was noticed in 253 (37.6%) patients. The cut section of appendix showed wall abscess in 474
(70.4%) cases, and mucosal ulceration in 325 (48.2%). Necrotic foci in mucosa were seen in
188 (27.6%) cases, and in 61 cases (9%) the necrosis was extending through the wall up to
serosa. Histopathology revealed marked acute inflammation in 416 (61.8%) cases, moderate
inflammation in 92 (13.7%), and mild inflammation in 47 (6.9%); while in 118 cases the appendix
had no evidence of inflammation (giving negative appendectomy rate of 17.5%). Negative
appendectomy rate in females was 29.2% compared to 12.7% in males. Probable alternate
diagnoses are also addressed. Conclusions: The negative appendectomy can be avoided
in many cases if ultrasound facilities were available during odd hours of patient presentation.
Similarly, the rate of negative appendectomy can be further reduced in adults, especially females
around puberty and reproductive age, by the provision of laparoscopy during emergency hours
of the day.