INTESTINAL OBSTRUCTION CAUSED BY APPENDICITIS: A SYSTEMATIC REVIEW

Abstract

Background

The known complications of appendicitis include perforated appendicitis with generalised peritonitis, appendiceal mass, appendiceal abscess, sepsis, adhesion formation and in a few occasions, small bowel intestinal obstruction.

Aim

To review published cases of intestinal obstruction due to appendicitis with a view to better understand the pathophysiology of this complication.

Methodology

A search of the literature in the MEDLINE database, using PubMed and OvidSP, Scopus, Google Scholar and Cochrane Databases with the following MeSH terms: (Appendicitis or appendiceal mass, appendiceal abscess or appendiceal adhesion band) and (intestinal obstruction, intestinal herniation, intestinal strangulation, intestinal knotting and paralytic ileus) was done. Also, these searches were restricted according to the following MeSH limits: (a) January 1, 1950 to July 31, 2016, (b) English articles (c) Human.

Results

Overall, 27 articles reported 45 patients with intestinal obstruction due to appendicitis. Of the 30 (66.7%) patients that the gender was indicated, 22 (48.9%) were male while 8 (17.8%) were female. In 38 (84.4%) cases the cause was mechanical obstruction resulting from one or a combination of the following: (a) appendix laid across loops of bowel bound down by adhesions, (b) herniation through a ring or gap formed by the appendix tip being attached to its base, (c) appendix tip attached to the bowel causing a torsion, (d) kinking of the bowel, (e) complex knotting. Pre-operative diagnosis was a major challenge and so, none was approached through incision based on the McBurney’s point.The outcome of treatment which was mostly achieved by immediate appendectomy followed by adhesiolysis was sufficient and often gave good results.

Conclusion

This study has shown that appendicitis is an important cause of intestinal obstruction. Even though pre-operative diagnosis is still a major challenge, clinical evaluation and a high index of suspicion are key to diagnosis

Introduction

Appendicitis is the inflammation of the vermiform appendix, usually resulting from bacterial infection, which may be precipitated by obstruction of the lumen by a fecalith1. Histopathologically, there is often a pan inflammatory involvement of all layers of the appendix. Appendicitis is said to be the commonest surgical emergency worldwide1, 2. Even though the reason for the frequent occurrence is yet to be known, the rate of complications is gradually increasing in the recent times2. Highly common and well known complications of appendicitis include perforated appendicitis with generalised peritonitis, appendiceal mass, appendiceal abscess and sepsis. While uncommon complications of appendicitis include peritoneal adhesion formation and small bowel intestinal obstruction. Intestinal obstruction being another surgical emergency with varied causes is not commonly thought to be caused by appendicitis3. However, in recent times, quite a number of cases of intestinal obstruction due to appendicitis have been reported 4, 5. Therefore, the aim of this study is to review published cases of intestinal obstruction due to appendicitis in order to better understand the aetiopathogenesis and pathology of this complication.

Material & Methods

Search methods

The Preferred Reporting Items of Systematic-Reviews and Meta-Analyses (PRISMA) guidelines were used in searching the literature in the MEDLINE database, using PubMed and OvidSP, Scopus, Google Scholar and Cochrane Databases with the following MeSH terms: (Appendicitis or appendiceal mass, appendiceal abscess or appendiceal adhesion band) and (intestinal obstruction, intestinal herniation, intestinal strangulation, intestinal knotting and paralytic ileus).2 These searches were restricted according to the following MeSH limits: (a) January 1, 1950 to July 31, 2016, (b) English articles (c) Human. A search of the references of captured articles was also performed. Titles, abstracts, and entire articles were reviewed. The search was done from 1^st-14^th August, 2016.

Inclusion and exclusion criteria

We considered an article to be eligible for review if it had reported appendicitis, appendiceal mass, appendiceal abscess, appendiceal adhesion band and/or causing intestinal obstruction, bowel herniation, intestinal strangulation and paralytic ileus. Articles that included meta-analyses, review articles without a case, letters to editor, descriptive techniques, and duplicate studies were excluded from the review process. Also, studies were excluded if insufficient data were provided. Eligible studies were also cross-referenced.

Information collection

Articles were organised into relevant categories and the following pieces of information were extracted from each article: author(s), year of publication, study design, number of patients in study, sex, position and length of appendix, etiological factors of intestinal obstruction, etiopathological mechanism of intestinal obstruction, mode of presentation, method of detection of intestinal obstruction, treatment method and also, the mortality and country where study was conducted.

Analysis

Analysis was done to determine demographic features of patients, etiopathological factors, mode of presentation, diagnosis, operative treatment and morbidity and mortality of cases using SPSS version 20[inc. Chicago].

Results

Systematic review chart

The flow chart and results of the systematic review are shown in Fig. 1. A total of 92 potential citations were initially identified using the different databases and references of articles. Twenty-seven articles met the inclusion criteria and were included in the final analysis. Eighteen articles were full [1 review & 17 case reports] articles while 9 were abstracts.

Fig. 1. Flow of Systematic Review.

Demographic features

Overall, 27 articles reported a total of 45 patients with intestinal obstruction due to appendicitis (Table 1). Of these articles, 1 (3.7%) was a review article, another 1 (3.7%) was case series, while the remaining 25 (92.6%) were case reports. The sex status was indicated in 30 (66.7%) reported cases of which 22 (48.9%) were male while 8 (17.8%) were female. The age range of reported cases was 3-82years with a mode of 36.

Table 1. Characteristics of studied articles.

S/No	Type of article	Title	No of Patients	Sex	Year	PI
1	Review	Mechanical small bowel obstruction due to acute appendicitis	10	M-7F-3	1965	Harris S
2	CR	Large bowel obstruction with acute appendicitis	1	M-1	1954	Croomes RRM
3	CR	Perforated acute appendicitis resulting from appendices adenoma presenting with small bowel obstruction: A case report	1	F	2011	Chen Y
4	CR	Appendiceal tie Syndrome a very rare complication of a common disease	1	F	2015	Awale Laligen
5	CS	Acute small-bowel obstruction caused by appendicular abscess	9	M-5F-3	2008	Kurkuzov OP
6	CR	Mechanical small bowel obstruction due to inflammed appendix wrapping around the loop of ileum	1	M	2005	Assenza M
7	CR	Mechanical occlusion due to acute appendicitis: Review of literature and report of a clinical case	1	?	1981	Macellari G
8	CR	Small bowel obstruction secondary to appendiceal tourniquet	1	F	2009	O’Donnell ME
9	CR	Illeal obstruction a rare complication due to appendicular band	1	M	2010	Niranjan A
10	CR	Small bowel obstruction caused by appendiceal tourniquet	1	?	2011	Deshmukh SE
11	CR	First case of villous adenoma of the appendix leading to acute appendicitis presenting as strangulated femoral hernia: Changes in management owing to concurrent adenoma	1	F	2008	Suppiah A
12	CR	Appendico-ileal knotting resulting in closed loop obstruction in a child	1	M	2002	Yang AD
13	CR	Appendicitis as a cause of intestinal strangulation: A case report and review	1	M	2009	Laxminayaran B
14	CR	Appendiceal tie Syndrome	1	?	2007	Menon T
15	CR	Two cases of strangulation of small intestine in the loop of the appendix	2	?	1963	Naumon ID
16	CR	Intestinal obstruction caused by a long appendix ensnaring a loop of ileum	1	?	1964	Srivatsan M
17	CR	An unusual complication of appendix (Intestinal obstruction)-case report	1	?	1969	Paliwal YD
18	CR	Mechanical small bowel obstruction caused by acute appendicitis	1	?	1969	Gupta S
19	CR	Appendicitis causing intestinal obstruction with strangulation	1	?	1973	Bose SM
20	CR	Neonatal perforated appendicitis associated with duodenal obstruction	1	?	1992	Sweed Y
21	CR	Duodenal obstruction caused by acute appendicitis with intestinal malrotation in a child	1	M	2015	Bicer S
22	CR	Appendico-ileal knotting mimicking adhesive bowel disease	1	F	2016	Okello M
23	CR	Duodenal obstruction caused by acute appendicitis with intestinal malrotation in an adult: A case report	1	M	1990	Ueo H
24	CR	Acute appendicitis presenting as small bowel obstruction: Two case reports	2	M-1F-1	2009	Sanjay H
25	CR	Acute appendicitis with intestinal non rotation presenting with partial small bowel obstruction diagnosed on CT scan	1	?	2000	Zissen R
26	CR	Perforated appendicitis presenting with ileo-caecal ulceration and mechanical intestinal obstruction	1	M	2008	Kareem H
27	CR	Intestinal obstruction secondary to appendiceal mucocele	1	M	1999	Mourad FH
CR=Case report, CS=Case Series, M=male, F=Female

Aetiopathogenesis

Among the articles that the mechanism of obstruction was clearly stated, they were further categorised into causes due to mechanical, paralytic ileus, strangulation and/or mesenteric ischaemia (Table 2). In majority 38 (84.4%) of cases it was due to mechanical obstruction resulting from one or a combination of the following (a) appendix laid across loops of bowel bound down by adhesions (b) herniation through a ring or gap formed by the appendix tip being attached to its base (c) appendix tip attached to the bowel causing a torsion (d) kinking the bowel (e) complex knotting.

Table 2. Classes of aetiopathologic Mechanism.

Cause	n (%)	Mechanism n (%)
Mechanical	38(84.4	(a) Appendix laid across loops of bowel bound down by adhesions 31(68.9)
		(b) Herniation through a ring of gap formed by infolding and attachment of appendix 2(4.4)
		(c) Appendix tip attached to the bowel causing a torsion 1(2.2)
		(d) Kinking the bowel 2(4.4)
		(e) Complex knotting 2(4.4)
Paralytic Ileus	1(2.2)	Paralytic ileus 1(2.2)
Strangulation	2(4.4)	aCompression 1(2.2)
		(b) Torsion and Closed loop 1(2.2)
Mesenteric Ischaemia	2(4.4)	Thrombo-embolism 2(4.4)
Total	45(100)

Clinical presentation

The major symptoms that characterised clinical presentations were abdominal pain and distension (Table 3). The clinical presentations were categorised into three: (a) patients whose clinical features were predominantly those of intestinal obstruction such as abdominal pain, abdominal distension and vomiting were 23 (51.1%) case reports (b) those that are predominantly with features of appendicitis such as previous history of recurrent right iliac fossa pain, loss of appetite, fever, abdominal distension, anorexia and vomiting were 16(35.6%). The last group had a mix of features such as fever, abdominal pain, anorexia; abdominal distension, vomiting and constipation were 6 (13.3%).

Table 3. The major symptoms that characterized clinical presentation.

Symptoms	Frequency	%
Abdominal Pain Mainly right sided/iliac fossa Diffuse Location not detailed	45	100
Abdominal distension	43	95.6
Vomiting	39	86.7
Fever	41	91.1
Anorexia	28	62.2
Nausea	27	60.0
Dirrhoea	9	20

Diagnostic evaluation

Clinical diagnosis was key in all the 45 [100%] patients. Ultrasound was not an imaging modality in the diagnostic evaluation of these patients as none had ultrasound done. Abdominal CT scan was done in 4[8.9%] of the cases and it revealed peri-appendicular inflammatory exudates and features of small bowel obstruction.

Operative treatment

The approach to surgical management of all the 45 [100%] cases was through a midline incision. Though in 3 [6.7%] cases, the initial approach was through the McBurney’s point but was later changed to a midline incision for better exposure. Thirty-two [71.1% ] cases had appendicectomy only while 3[6.7%] had appendicectomy and segmental resection due to strangulation. The remaining 10 [22.2%] had appendicectomy and peri-appendicular adhesiolysis.

Discussion

The first case of intestinal obstruction due to acute appendicitis was described by Hotchkiss3. Since then few additional cases were reported5,6 . A review of published cases from 1950 to 2016 was undertaken to characterise the various risk factors, causes, predominant clinical presentation, and aetiopathologic mechanisms

Epidemiology

The intestinal obstruction due to appendicitis occurred predominantly among males and had a wide age range. The implication of this finding was that no age was exempted as it has been reported in a 3-year old child as well as an elderly patient of over 80 years. Broadly, cases had been reported in most parts of the 6 continents in the world with majority coming from America. Perhaps, advanced diagnostic evaluation in areas with high number of cases could have played a role.

Aetiopathological mechanisms

In 1909, Hawks6 divided the causes into mechanical and septic appendicitis or a combination of both. In 2009, Bhandari et al4 classified intestinal obstruction secondary to appendicitis into four types: adynamic, mechanical, strangulation, and the one caused by mesenteric ischemia. The review of published cases showed that most of the causes could be conveniently grouped into mechanical, paralytic and ischaemia.

Mechanical:

The commonest cause is mechanical7, 8.The various ways in which appendicitis could mechanically cause intestinal obstruction include: (a) appendix which lay across loops of bowel and get bound down to the posterior peritoneum at the tip and base by adhesions when it is inflamed. The description and the findings of the case reported by Awale et al2 supported this assertion. (b) the appendix attaching to the wall of the small bowel and form a fulcrum for torsion or a kink that could lead to the development of symptoms of intestinal obstruction. (c) the tip of the inflamed appendix could, get attached to the posterior peritoneum or it base and form a gap. This gap becomes a channel through which bowel could herniate and get obstructed. In 2005, a review done by Assenza et al7 reported about six of such cases. (d) Another mechanism that was once noted was an inflamed appendix forming a complex knot with any part of the small bowel9.This complex knot was noted in two case reports where the inflamed appendix formed a complex knot and cause intestinal obstruction at the level of the duodenum10^-12.

It is important to note that the appendix is a mobile organ and could assume or take variable positions within the abdomen. Hence, during appendicitis it has an increase tendency to move and get adhered to surrounding structures resulting in mechanical small bowel obstruction12.

Paralytic ileus:

Another mechanism is by causing temporary paralytic ileus. The pro-inflammatory mediators released during early part of the inflammation have some inhibitory effect on the bowel peristaltic movement. Thus, the paralytic ileus presents itself with features of intestinal obstruction.

Ischaemia:

Gupta et al13 was the first person to describe a case of intestinal obstruction due to appendicitis that was thought to have resulted from ischaemia. The ischaemia may result from thrombo-embolic phenomenon arising from the inflammation in and around the appendix including the meso-appendix or simply an oedematous appendix lying over a major branch of the ileal artery. Similarly, in the review done by O’Donnell et al14 they reported that the intestinal obstruction of some cases was due to a thrombo-embolic phenomenon to the major branches of ileal artery following the appendicitis.

Strangulation:

In the report by Bose et al15 they found that the intestinal obstruction was caused by an inflamed appendix that wrapped round a long loop of small bowel thereby leading to a closed loop obstruction which was strangulated. Many reports4, 16 have attempted to put this as the fourth class.

Predisposing factors

Mobility:

One major predisposing factor that is thought to influence and lead to this number of mechanisms is the fact that the appendix is quite mobile. It can move and assume varied positions from the normal within the abdomen. Bhandari et al4 in their report suggested that the mobility of the appendix enhanced its attachment to the other surrounding structures such as the ileum, the mesentery of the ileum, the caecum and/or the colon, the posterior peritoneum and right tubo-ovarian complex.

Congenital malrotation:

Closely linked to this high mobility is congenital malrotation of the bowel. This congenital anomaly is devoid of the usual attachments and proper positioning of the bowel, thereby, further enhances the mobility that the appendix already has. This often leads it to unusual locations including upper part of the abdomen in the region of the duodenum and the left side of the abdomen. Therefore, the risk of developing intestinal obstruction due to appendix appears to be more in patients with congenital malrotation of the bowel than normally rotated10, 11. Zissen et al17 reported a case of appendicitis presenting with small bowel obstruction in a patient with intestinal malrotation.

Gender:

The gender of the patient appears to be another significant risk factor. In majority of the cases that have been published, 66.7% of the patients were noted to be male. Further studies are, however, required to really establish the role of gender in intestinal obstruction due to appendicitis.

Size:

The size of the appendix is another very strong predisposing factor18. In the various reports that were published by Awale et al2 and Bhandri et al4 it was noted that the length of the appendix could have, probably, been a predisposing factor to causing the small bowel obstruction. It is quite logical that if the appendix is long, it will be able to accommodate the circumference and wrap round the bowel easily and cause obstruction. However, prospective study is required to further establish this fact.

Long meso-appendix:

The length of the mesoappendix is believed to also facilitate the movement and variation in position of the appendix1.

Position:

Pre-ileal position of the appendix also appears to be a common predisposing factor. In the cases that have been reported, more patients with pre-ileal appendix were noted to have developed this condition4,14. In most cases, the mechanism was for the appendix to lie over the loops of terminal ileum and compress on them especially when the tip is eventually plastered down by adhesions to the posterior peritoneum.

Recurrent illness:

Recurrent inflammation/illness is another important factor as majority of the patients that developed the condition had recurrent appendicitis.

Clinical classification

Some have reported4,7 various clinical entities for this condition. The first clinical scenario is when features of intestinal obstruction predominate over those of acute appendicitis. In this case, history that is suggestive of appendicitis may be absent; pre-operative diagnosis of the cause of obstruction will be difficult, and it is usually due to mechanical effect from recurrent or subacute appendicitis. Diagnosis may only be established at intra-operative findings; this entity appears to be the commonest one among the published cases. The other clinical entity is when the features of appendicitis predominate over those of intestinal obstruction. In this case, the intestinal obstruction occurs in the acute supportive phase of appendicitis. Therefore, the intestinal obstruction may be due to paralytic ileus, mass effect, abscess or thrombo-embolic phenomenon19^-21. The most uncommon clinical entity is when features of both conditions pre-dominate, posing a greater challenge to pre-operative clinical diagnosis.

Diagnostic evaluation

Pre-operative diagnosis has been and is still a major challenge. In all the cases that have been reported, pre-operative diagnosis was difficult2,4,7,14. Only in two cases that abdominal CT scan suggested intestinal obstruction due to appendicitis. The CT scan findings were noted to be features of inflammation around the appendix in the presence of both clinical and radiological features of intestinal obstruction4. In addition, CT scan may reveal features of ischaemia and the presence of exudates if present17. However, these CT scan findings could mostly be seen in the early part of the inflammation. It therefore means that at late stage when inflammation may have resolved, the use of abdominal CT scan may not be reliable. Similarly, in elderly people, presentation of both intestinal obstruction and appendicitis may be atypical and in such instances diagnosis could be delayed with potential for increased morbidity and mortality.

Operative treatment

It is important to note that the best approach to the operative management of this condition is through laparotomy 4. It gives better exposure, easy identification and optimal management. The intra-operative treatment of the intestinal obstruction, which is mostly achieved by immediate appendectomy followed by some adhesiolysis is sufficient and often gives good results except where there is associated strangulation of the loops of bowel15,16. Even then, when the patient present early and the viability of the loops of bowel could still be restored, performing appendicectomy alone suffices. However, when gangrene sets in, segmental resection and anastomosis of the bowel, in addition to the appendicectomy should be done15. On the other hand, if the gangrenous bowel is extends close to the ileo-caecal junction, the appropriate treatment is a limited right hemicolectomy. Of course, these additional procedures may increase hospital stay, mortality and even the risk of residual morbidity if the patient eventually survived. This review revealed limited information on the laparoscopic management of intestinal obstruction secondary to appendicitis22^-23. However, going by the rapid advancement in laparoscopic surgery, it is believed that laparoscopy holds a lot of promise to both the diagnostic as well as the therapeutic management of this entity.

Limitations

A limitation of this review is the small sample size and absence of original full length scientific manuscripts as almost all the samples were case reports and case series

Also, some local reports not available to our sources of data (Pubmed, Scopus, Ovisp, Google Scholar and Cochrane) may be missed in our analysis.

Probably, a large series of cases may be required to further elucidate the etiopathological mechanism of intestinal obstruction in patients with appendicitis.

Therefore assessment of these results should be interpreted in the setting of these deficiencies.

Conclusions

This study has shown that appendicitis is an important cause of intestinal obstruction. Even though pre-operative diagnosis is still a major challenge, clinical evaluation and a high index of suspicion are key to diagnosis.