A review of the function and evolution of the cecal appendix

Therapeutic effectiveness and influencing factors of laparoscopic appendectomy with mesoappendix dissection in the treatment of acute appendicitis

BACKGROUND

Acute appendicitis (AP) is a frequently encountered surgical emergency, and appendectomy is conventionally regarded as the predominant treatment modality. Nevertheless, the therapeutic efficacy of this surgical approach remains to be improved. Thus, the exploration and implementation of surgical refinements are necessary.

AIM

To elucidate the therapeutic effectiveness and influencing factors of laparoscopic appendectomy (LA) with mesoappendix dissection in the treatment of AP.

METHODS

First, 150 patients with AP who visited Shangrao Municipal Hospital between January 2022 and June 2024 were enrolled in this study. Among them, 72 patients were assigned to the control group to receive conventional LA, whereas 78 cases were included in the observation group for LA with mesoappendix dissection. Subsequently, indicators such as therapeutic effectiveness, surgical indices (operation time, intraoperative blood loss, and hospital stay), postoperative recovery indices (time to ambulation, gastrointestinal function recovery time, and time to food intake), incidence of adverse events (postoperative bleeding, pelvic infection, puncture site infection, and ileus), and serum inflammatory factors [tumor necrosis factor (TNF)-α, interleukin (IL)-6, and C-reactive protein (CRP)] were collected and comparatively analyzed, and the influencing factors of therapeutic effectiveness in patients with AP were analyzed.

RESULTS

Compared with the control group, the observation group had higher clinical therapeutic effectiveness, less operation time, intraoperative blood loss, and hospital stay; shorter time to ambulation, gastrointestinal function recovery, and food intake; and a lower total incidence of adverse events, and this difference is statistically significant. In addition, the expression levels of various serum inflammatory factors in the observation group were significantly reduced postoperatively, which were markedly lower than those in the control group. Moreover, sex, age, body mass index, time from acute onset to admission, family medical history, preoperative TNF-α, preoperative IL-6, preoperative CRP, and treatment modality were identified to be not independent factors affecting the therapeutic effectiveness of LA with mesoappendix dissection in patients with AP.

CONCLUSION

Overall, LA with mesoappendix dissection has a remarkable curative effect in treating patients with AP, which is worthy of clinical promotion.

Exploring the Immunological Role of the Microbial Composition of the Appendix and the Associated Risks of Appendectomies

The appendix, an integral part of the large intestine, may serve two purposes. First of all, it is a concentration of lymphoid tissue that resembles Peyer's patches. It is also the main location in the body for the creation of immunoglobulin A (IgA), which is essential for controlling intestinal flora's density and quality. Second, the appendix constitutes a special place for commensal bacteria in the body because of its location and form. Inflammation of the appendix, brought on by a variety of infectious agents, including bacteria, viruses, or parasites, is known as appendicitis. According to a number of studies, the consequences of appendectomies may be more subtle, and may relate to the emergence of heart disease, inflammatory bowel disease (IBD), and Parkinson's disease (PD), among other unexpected illnesses. A poorer prognosis for recurrent Clostridium difficile infection is also predicted by the absence of an appendix. Appendectomies result in gut dysbiosis, which consequently causes different disease outcomes. In this review, we compared the compositional differences between the appendix and gut microbiome, the immunological role of appendix and appendix microbiome (AM), and discussed how appendectomy is linked to different disease consequences.

Expression of Calretinin in the Cecal Muscularis Interna: Observation and Hypothetical Relevance to Appendicitis

BACKGROUND

The unexpected observation of calretinin immunoreactivity in smooth muscle cells in the muscularis propria of the cecum led to a more detailed examination of calretinin expression and its possible relationship to propulsive contractile activity around the vermiform appendix.

METHODS

Immunohistochemistry and RNA in situ hybridization were performed to analyze calretinin expression in intestinal samples from 33 patients at ages ranging from mid-gestation fetuses to adults, as well as in some potentially relevant animal models. Dual immunolabeling was done to compare calretinin localization with markers of smooth muscle and interstitial cells of Cajal.

RESULTS

Calretinin expression was observed consistently in the innermost smooth muscle layers of the muscularis interna in the human cecum, appendiceal base, and proximal ascending colon, but not elsewhere in the intestinal tract. Calretinin-positive smooth muscle cells did not co-express markers located in adjacent interstitial cells of Cajal. Muscular calretinin immunoreactivity was not detected in the ceca of mice or macaques, species which lack appendices, nor in the rabbit cecum or appendix.

CONCLUSIONS

Localized expression of calretinin in cecal smooth muscle cells may reduce the likelihood of retrograde, calcium-mediated propulsive contractions from the proximal colon and suppress pro-inflammatory fecal stasis in the appendix.

Colonoscopy in the diagnosis and management of appendiceal disease

In this editorial, we comment on the article published in the recent issue of the World Journal of Gastrointestinal Endoscopy. We focused on the understanding of appendiceal disease, and the various options for diagnosis and treatment via endoscopy. Some factors affecting the diagnosis and management of appendiceal diseases are also discussed. The existence of any organ has its natural rationality, and the appendix is such a magical organ. A growing number of experts and scholars have gradually come to a consensus that the appendix is not a useless evolutionary relic. There are many lymphocytes and lymph nodes in the appendix wall, which has a strong immune function, and this function is particularly important for children and adolescents. Many intestinal probiotics in the appendix are very helpful for maintaining the balance of the intestinal flora. With the continuous progress of endoscopic technology, endoscopic treatment involving preservation of the appendix has shown great advantages over surgery. In the diagnosis of appendiceal inflammation and neoplasms, colonoscopy, endoscopic retrograde appendicography and choledochoscopy help assess conditions of the appendix. Endoscopic retrograde appendicitis therapy, abscess drainage under colonoscopy, fenestration of abscess under colonoscopy, and endoscopic or natural orifice transluminal endoscopic surgery resection of appendiceal neoplasms are safe and effective endoscopic treatments for appendiceal disease. New breakthroughs in the application of endoscopy in the appendix are expected to occur in the near future.

Correlation between the presence of a cecal appendix and reduced diarrhea severity in primates: new insights into the presumed function of the appendix

Increased severity or recurrence risk of some specific infectious diarrhea, such a salmonellosis or Clostridium difficile colitis, have been reported after an appendectomy in human patients. While several other mammals also possess an appendix, the suspected protective function against diarrhea conferred by this structure is known only in humans. From a retrospective collection of veterinary records of 1251 primates attributed to 45 species, including 13 species with an appendix and 32 without, we identified 2855 episodes of diarrhea, 13% of which were classified as severe diarrhea requiring a therapeutic medication or associated with a fatal issue. We identified a lower risk of severe diarrhea among primate species with an appendix, especially in the early part of life when the risk of diarrhea is maximal. Moreover, we observed a delayed onset of diarrhea and of severe diarrhea in species possessing an appendix. Interestingly, none of the primates with an appendix were diagnosed, treated or died of an acute appendicitis during the 20 years of veterinarian follow-up. These results clarify the function of the appendix among primates, as protection against diarrhea. This supports its presumed function in humans and is congruent with the existence of a selective advantage conferred by this structure.

The vermiform cecal appendix, expendable or essential? A narrative review

PURPOSE OF REVIEW

The vermiform cecal appendix is a small thin pouch-like tube of intestinal tissue situated in the lower right abdomen. It is attached at the junction of the large intestine between the ascending colon and small intestine. Historically, the appendix has been labeled redundant with no significant function, a remnant of evolution. This idea was thought to represent a function that may have been critical for survival that became nonsignificant over time. Evolutionary biologists deemed it to be a vestigial organ that early in human evolution was a dedicated organ that was useful and exploited by herbivorous ancestors.

RECENT FINDINGS

Currently, the vermiform cecal appendix has generated significant renewed research interest. As such it has been reported to present a site with a high concentration of lymphoid tissue and a biofilm microbiome that approximately mirrors that which is found in the large bowel.

SUMMARY

Research suggests that the vermiform cecal appendix may be the site of a safe-house biofilm that could re-inoculate the large bowel. Given that the appendix has no known role in digestion, the network of lymphoid tissue and microbiome could constitute an initial site of bacterial translocations that can influence early life ontology and immunological tolerance. A dysbiotic microbiome in the appendix is posited to trigger inflammatory sequelae.