Congenital absence of appendix: A Surgeon's dilemma during surgery for acute appendicitis.

Congenital absence of the vermiform appendix is very rare in human beings with a reported incidence of 1 in 100,000 cases. Here, we report an incidence of a surgeon's dilemma to detect such a rare finding during surgery for a diagnosed case of acute appendicitis.

INTRODUCTION

The vermiform appendix is the most commonly cited and the most disputed vestigial organ in our body. Congenital absence of the vermiform appendix is exceptionally rare. However, it becomes fairly difficult to convince the parents in a single surgeon private setup when one encounters such a rarity that to while operating in a diagnosed case of acute appendicitis. In our case, there was a lot of resentment among the parents for conversion into open surgery when appendix was not detected by laparoscopy although they had signed the consent earlier.

CASE REPORT

A 5-year-old male child; the only child of his anxious parents, presented with right lower abdominal pain for 5 days, low-grade fever for 3 days and 2 episodes of nonbilious vomiting. Pain was of moderate intensity and localized to right iliac fossa without any shifting, radiation or referral. Fever was low-grade 99°F to 100°F without chills and rigors. He had 2 episodes of nonbilious vomiting immediately after forced feeding by mother. His bowel and bladder habits were normal. There was no past history of similar attacks. He had not undergone any surgical intervention before nor had any contact history with tuberculosis, drug intake or significant medical or surgical disorder. He was taking oral antibiotics and analgesics from their family physician.

On examination, the baby had fever of 100°F and tachycardia. Abdominal examination revealed tenderness with guarding in right iliac fossa.

Blood investigations revealed leukocytosis (12,000/cc) with neutrophilia (85%). Rest of blood and urine investigations was normal. His X-ray abdomen was also normal. However, ultrasonography of abdomen was reported as acute appendicitis with inflammatory mass formation measuring 6.1 cm × 1.4 cm and minimal collection at right iliac fossa along with mesenteric lymphadenopathies. The appendix was not visualized sonologically. It was the mass formation that was interpreted as appendicular lump due to its position.

With the provisional diagnosis of appendicular lump, the baby was managed conservatively with intravenous antibiotics, intravenous fluids and bowel rest for 1 week. However, due to the persistence of pain in spite of the conservative management laparoscopic appendectomy under general anesthesia was planned after 1 week.

Intra-operative findings

On laparoscopy omentum was seen in right iliac fossa. After retraction of the omentum from right iliac fossa, the cecum and ileum were visualized to be normal. There were small mesenteric lymph nodes, but the appendix could not be visualized even after mobilization of the ileocecal junction. Failing to visualize the appendix by laparoscopy, it was decided to convert to open appendectomy. Ileocecal junction then approached via right iliac fossa transverse skin crease incision. The point of convergence of the three teniae coli was delivered to the wound [Figure 1], but the vermiform appendix could not be detected. The retrocecal space and ileocecal area were thoroughly explored to conform the absence of appendix [Figure 2]. A careful search for Meckel's diverticulum was also unproductive. The paracecal mesenteric lymph nodes were excised and sent for histopathology study which later revealed reactive hyperplasia.

Figure 1

Convergence of teniae coli: Absence of appendix

Figure 2

Mobilization of cecum: Paracecal lymph nodes

Abdomen was closed after discussion with the parents. The baby improved symptomatically and was discharged after 1 week. There was no recurrence of pain on follow-up. The cause of his condition was put to nonspecific mesenteric lymphadenitis.

DISCUSSION

The vermiform appendix is the most commonly cited and the most disputed vestigial organ in our body. As the epithelium of the appendix is coated with a biofilm of commensal bacterial flora that may play a role in gut immunity, it is thought that the appendix is preserved by natural selection.[1]

A fully developed appendix is seen in 10 weeks old embryo as the distal end of the cecal pouch that failed to grow as fast as the remaining cecum. The cecoappendiceal outgrowth is said to be capable of considerable morphological variations. The three teniae meet together where the appendix joins the cecum and forms the outer longitudinal muscle layer of the appendix. Therefore, the teniae are a good landmark to follow to identify the appendix, especially the anterior teniae. The relation of the base of the appendix is constant and is 2–5 cm below the ileocecal valve on the posterior medial aspect.[2]

Agenesis of appendix is a rare anatomic finding; Morgagni reported the first case in 1719.[3] Collins found 1 case in 104,066 appendectomies or an incidence of 0.0009%.[4]

The cause of an absent appendix is postulated to be secondary to an intrauterine vascular accident.[5] Arrest of development may occur at any stage and give rise to either absence of cecum and appendix (type 1), blunt conical cecum without appendix (type 2), longitudinal symmetrical cecum with longitudinal muscle bands converging toward its apex, but without appendix (type 3), or asymmetric cecum without appendix (type 4).[6] The case discussed here is type 3 variety of congenital absence of appendix.

The diagnosis of agenesis of the appendix should not be made unless the ileocecal area and retrocecal space are thoroughly explored. Most case reports of absence of appendix are usually noted in adult patients or adult cadavers but rarely in children.[7] The case discussed here is a boy of 5 years old.

Associated mesenteric lymphadenitis is sometimes noted during laparoscopy or laparotomy for congenital absence of appendix.[8] This was also found in this case. However, an auto-amputated appendix may also be the focus for inflammation within the peritoneal cavity.[9] In other cases, no apparent cause for the patient's symptoms is found.[10]

CONCLUSION

Congenital absence of appendix is a diagnosis of exclusion at laparotomy. Surgeons must be aware of the existence of this rare condition.

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Nil.

Conflicts of interest

There are no conflicts of interest.