Expression of neuropeptides in normal and abnormal appendices

Neurogenic appendicopathy: an underestimated disease-systematic review of the literature

PURPOSE

Appendectomy is one of the most frequently performed surgeries worldwide, but neurogenic appendicopathy (NA) remains a poorly understood disease with controversial clinical management. The aim of this review was to obtain a clear definition of the disease and summarize its management.

METHODS

We performed a systematic review of the literature on NA in PubMed, EMBASE, Web of Science, and Cochrane databases from inception to 19/01/2021 according to PRISMA statement standards. Eligibility criteria were original articles examining histopathology, clinical management, and/or follow-up of patients with NA. The literature review is complemented by a clinical case.

RESULTS

In 40 articles, the estimated incidence of NA among appendectomies performed in patients with a suspicion of acute appendicitis (AA) was 10.4% (N = 740, range 1.8-32%). NA more frequently causes recurrent and longer lasting pain compared to AA; however, these diseases are usually not clinically or radiologically distinguishable. Based on our analysis, NA is defined as the presence of three criteria: (1) clinical presentation of AA, (2) absence of acute inflammation on histopathology, and (3) presence of S-100-positive spindle cells or proliferation of Schwann cells. Laparoscopic appendectomy has been shown to be a safe and successful treatment.

CONCLUSIONS

NA is a poorly known disease, which may clinically appear as AA but is often related to recurrent and longer lasting abdominal pain. Patients with NA may suffer for years before diagnosis. In cases of typical symptoms, appendectomy should be performed even in cases of macroscopically and radiologically normal-appearing appendices with normal laboratory results.

Neuroendocrine apendicopathy in morphologically normal appendices of patients with diagnosis of acute appendicitis: Diagnostic study

Background

About 15%–25% of appendices removed to treat acute appendicitis present normal macro- and macroscopic morphology. The objective of this study was to verify an association of proinflammatory, neuroendocrine and immune mediators with morphologically normal appendices removed from patients with clinical laboratorial and imaging characteristics of acute appendicitis.

Materials and methods

Appendices removed from 121 adult patients of both genders were distributed into three groups according to their following characteristics: group 1: 53 macro- and microscopically normal appendices from patients with clinical, laboratorial and imaging diagnosis of acute appendicitis; group 2: 24 inflamed appendices from patients with clinical, laboratorial, imaging and histopathological diagnosis of acute appendicitis; group 3: 44 normal appendices from patients submitted to right colectomy to treat localized ascending colon adenocarcinoma. All appendices were immunohistochemically studied for gastrin inhibitor peptide, mast cell tryptase, vascular endothelial growth factor; intestinal vasoactive peptide, tumor necrosis factor alpha, interleukin 1, prostaglandin E2, gene-protein product 9.5, CD8 T lymphocytes, synaptophysine, enolase, and S100 protein.

Results

The group 1 revealed increased levels of synaptophysine, enolase, mast cell tryptase and PGP-9.5 comparing with the other two groups. The group 2 presented increased levels of interleukin 1, CD8 T lymphocytes and prostaglandin E2 comparing with the other two groups. The group 3 confirmed the normal levels of all these neuroendocrine, immune and proinflammatory mediators.

Conclusions

Morphologically normal appendices removed from patients with clinical and complementary exams indicating acute appendicitis have appendicular neuroimmunoendocrine disorder associated with the mediators synaptophysin, enolase, mast cell-related tryptase and gene-protein product 9.5.

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15 % to 25% of the appendices removed to treat acute appendicitis have normal appearance with no inflammatory signs.

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All patients with normal appendices removed due to acute appendicitis do not present similar clinical manifestation anymore.

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Inflammatory and neuroendocrine appendicopathies present similar clinical laboratorial and imaging characteristics.

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Morphologically normal appendices removed from patients indicating acute appendicitis have neuroimmunoendocrine disorders.

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Synaptophysin, enolase, mast cell tryptase and gene-protein product 9.5 are associated with neuroimmunoendocrine disorders.

Neuroimmunoendocrine peptides on inflammed and morphologically normal appendices removed due to clinical acute appendicitis

INTRODUCTION

Despite clinical characteristics and complementary exams indicate acute appendicitis, 15% to 40% of all appendectomies result in removal of appendices with normal macro- and micromorphological aspects. Even so, manifestations of acute abdomen disappear immediately after the appendectomy, and never show back again.

OBJECTIVE

To assess changes of neuroimmunoendocrine peptides on removed appendices due to clinical presentation of acute appendicitis.

METHOD

This article presents an updated revision of acute appendicitis, based on references found on PUBMED, LILACS, MEDLINE, WHOLIS and SciELO, using key words "acute appendicitis", "neuroimmune appendicitis", "neurogenic appendicopathy", and "incidental appendectomy".

RESULTS

Fourteen neuropeptides were analyzed by different authors who suggested the presence of neurogenic appendicopathy in morphologically normal appendices removed from patients with clinical presentation suggesting acute appendicitis.

CONCLUSION

The etiopathogeny of acute appendicitis continues to be unknown, and there is a great possibility that patients with morphologically normal appendices with clinical presentation of acute appendicitis that heal after appendectomy present a neuroimmunoendocrine disease.

Laparoscopic assisted two port open appendicectomy

OBJECTIVES

The laparoscopic appendicectomy can be performed using one to several ports. We present our experience of two port laparoscopic assisted open appendicectomy. The objective was to assess the results retrospectively in terms of complications and its limitations.

METHODS

Between years 1998-2007, a two port laparoscopic assisted appendectomy was attempted in 2380 adult patients with suspected appendicitis. The patients with localized or generalized peritonitis were included. The appendicectomy was performed via an assisted two port method using 10 mm umbilical optical port and another 10 mm port in right iliac fossa. The children aged 12 and below and pregnant patients were excluded. All patients had their laparoscopic appendicectomy within 48 hours of admission.

RESULTS

Two port laparoscopic assisted appendicectomy was successful in 86.9% of cases. Acute appendicitis was the cause of acute abdomen in 88.9% of the patients. The accessory port was required in 8.5% of patients to complete the appendicectomy and the conversion rate to open was 4.6%. The mean operation time was 25 minutes and the mean hospital stay was 1.5 days. The port site infection was seen in 14, bleeding in 20, parietal wall abscess in three cases and intra-abdominal abscesses in 4 patients.

CONCLUSION

This approach is simple, can be converted to total intracorporeal by inserting accessory port or to open appendicectomy when required and has advantage of full laparoscopy of abdomen. It has its limitations in cases of extreme obesity, thick mesentery, gangrenous appendix, very large and thick appendix, and difficulty in finding the appendix, control of bleeding, division of adhesions and to deal with other associated pathology. Cost was minimized by using non-disposable port. The overall morbidity was low. There were no specific complications related to this technique and incidence of port site infection was similar to other approaches of laparoscopic appendicectomy.

Association between gallstone-evoked pain, inflammation and proliferation of nerves in the gallbladder: a possible explanation for clinical differences

OBJECTIVE

To investigate whether enhanced neuroproliferation could be involved in the pathogenesis of gallstone pain.

MATERIAL AND METHODS

Gallbladders from 117 patients with gallstones and 43 controls were examined. The gallbladder samples were immunostained against the pan-neuronal marker PGP 9.5 and the number of nerves and nerve area per tissue area estimated.

RESULTS

More nerves and an increased nerve area per tissue area were found in uncomplicated symptomatic gallstone disease. In comparison, acute cholecystitis displayed a significantly (p=0.01) decreased number of nerves and nerve area per tissue area. In both categories, the gallbladder neck contained more nerves (p=0.06 and 0.04, respectively) and an increased nerve area per tissue area (p=0.034 and 0.008, respectively) than the body.

CONCLUSIONS

Uncomplicated disease showed enhanced neuroproliferation, significantly more in the gallbladder neck, whereas significantly fewer nerves were observed in acute cholecystitis. Nerve growth alteration may play a role in uncomplicated gallstone pain but the pathology may be different in inflammation.

Changes in spontaneous behavior in rats exposed to experimental disc herniation are blocked by selective TNF-alpha inhibition

STUDY DESIGN

Study of pain behavior in animals by observation of changes in spontaneous behavior.

OBJECTIVES

To assess if selective inhibition of tumor necrosis factor alpha may reduce changes in spontaneous behavior induced by experimental disc herniation in the rat as previously reported.

SUMMARY OF BACKGROUND DATA

It is known that the proinflammatory cytokine tumor necrosis factor alpha may play a key role for the nucleus pulposus-induced nerve dysfunction seen in experimental set ups. However, it is not known if tumor necrosis factor alpha is also involved in pain production induced by the same procedure.

METHODS

Thirty-two rats were used for the study. Twenty-two rats had an L4-L5 disc incision combined with a displacement of the L4 dorsal root ganglion. Twelve of these rats received an intraperitoneal injection of 0.125 mL of 10 mg/mL Remicade, and the remaining 10 were left untreated. Ten rats only had the L4-L5 disc exposed and formed the control group. The day before surgery and days 1, 3, 7, 14, and 21 after surgery, the rats were videotaped from below during a 20-minute period. The duration of four specific behaviors were determined and compared between the three experimental groups at each time point.

RESULTS

Similar to a previous study, the nontreated showed increased signs of focal pain behavior (rotation of the head towards the operated leg and lifting of the operated leg) during the first 7 postoperative days. Treatment with the tumor necrosis factor alpha-inhibitor infliximab significantly reduced this behavior. At day 14, there were no differences between the groups, and at day 21, the nontreated group displayed reduced locomotion and increased immobility, similar to previous observations. Tumor necrosis factor alpha inhibition also seemed to reduce these behaviors.

CONCLUSIONS

The data of the study clearly indicate a role for tumor necrosis factor alpha in the studied behavior changes after experimental disc herniation in the rat. Clinical trials must be performed in order to assess if there may be a clinical use for tumor necrosis factor alpha inhibition in the treatment of sciatica due to disc herniation.

Origin of symptoms in diverticular disease

BACKGROUND

A significant number of patients with colonic diverticula experience unexplained, recurrent, short-lived but often debilitating abdominal pain and alteration in bowel habit. Such patients account for many medical consultations every year but, as our understanding of the cause of their symptoms remains imperfect, treatment options are limited. This article reviews the possible mechanisms that may be responsible for the symptoms of diverticular disease.

METHODS

Medline and Science Citation Index searches were performed to locate English language articles relating to colonic diverticula and symptoms published between January 1966 and July 2002. Manual cross-referencing was also performed and some historical articles were included.

RESULTS AND CONCLUSION

Several theories now exist about the mechanisms underlying the symptoms of diverticular disease. Initial studies suggested that they may be due to alterations in the intracolonic pressure, extrapolating earlier thoughts on the likely pathogenesis of diverticula. It seems more likely, however, that several inter-related processes, such as muscular dysfunction, visceral hypersensitivity and inflammation, are involved in symptom generation.

Nitrergic hyperinnervation in appendicitis and in appendices histologically classified as normal

CONTEXT

The pathogenesis of appendicitis remains poorly understood. Despite new diagnostic techniques, appendices removed from patients with suspected appendicitis often appear histologically normal on conventional examination. There is increasing evidence of involvement of the enteric nervous system in immune regulation and in inflammatory responses in the gastrointestinal system.

OBJECTIVE

To investigate the nitrergic innervation of (a) acutely inflamed appendices, (b) appendices classified as histologically normal from patients with a clinical diagnosis of appendicitis, and (c) normal control appendix specimens, using the whole-mount preparation technique.

PATIENTS AND DESIGN

Full-thickness specimens were collected from 28 acutely inflamed appendices (age range, 3.2-13.4 years), 31 histologically normal appendices removed from patients (age range, 5.7-13.6 years) with suspected appendicitis, and 23 histologically normal appendices from patients (age range, newborn to 12.1 years) undergoing elective abdominal surgery (controls). Whole-mount preparation using nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemistry and neuronal nitric oxide synthase immunohistochemistry were performed. The density of myenteric plexus was measured with a computerized analysis system.

RESULTS

The density of myenteric plexus in normal appendix specimens was similar to that of large bowel from the newborn period up to 3 years of age; this density decreased significantly thereafter. The myenteric plexus of normal appendix specimens from patients older than 4 years demonstrated smaller ganglia connected by thin nerve bundles, compared to larger ganglia and nerve bundles in large bowel. Significant neuronal hypertrophy was found in 55% of acutely inflamed and 41% of histologically classified normal appendix specimens. The myenteric plexus of these appendix specimens had even thicker nerve bundles connecting an increased number of ganglion cells.

CONCLUSIONS

Differences in the architecture of the myenteric plexus in patients older than 3 years suggest an altered function and motility of appendix in the early years of life. The significant increase in neuronal components of the myenteric plexus in a high proportion of acutely inflamed and histologically normal appendix specimens is unlikely to have developed during a single acute inflammatory episode. This suggests an underlying chronic abnormality as a secondary response to chronic luminal obstruction or repeated inflammatory episodes in the histologically normal appendix.