-
The Surgical Clinics of North America Feb 2010The rectum and anal canal form the last portion of the gastrointestinal tract. The rectum serves as a reservoir for fecal contents, and the anal canal regulates...
The rectum and anal canal form the last portion of the gastrointestinal tract. The rectum serves as a reservoir for fecal contents, and the anal canal regulates continence and defecation via synchronization of events regulated by complex interactions between sympathetic and parasympathetic nerves, striated and smooth muscle, and environmental factors. Normal function can be compromised by various pathologies. Investigation into these pathologies includes a detailed history and thorough physical exam and can be augmented by a number of different studies, including manometry, electromyelography, defecography, nerve stimulation, and compliance. Some of these techniques have incorporated the use of ultrasound and magnetic resonance imaging.
Topics: Anal Canal; Fecal Incontinence; Humans; Mucous Membrane; Muscle, Striated; Pelvic Floor; Rectum
PubMed: 20109629
DOI: 10.1016/j.suc.2009.09.001 -
Science Advances Sep 2023Intestinal stem cell (ISC) is a promising therapeutic target for inflammatory bowel disease. Cholesterol availability is critical for ISC stemness. Low plasma...
Intestinal stem cell (ISC) is a promising therapeutic target for inflammatory bowel disease. Cholesterol availability is critical for ISC stemness. Low plasma cholesterol is a typical feature of Crohn's disease (CD); however, its impact on mucosal healing remains unclear. Here, we identified an essential role of sorting nexin 10 (SNX10) in maintaining the stemness of ISCs. SNX10 expression in intestinal tissues positively correlates with the severity of human CD and mouse colitis. Conditional SNX10 knockout in intestinal epithelial cells or ISCs promotes intestinal mucosal repair by maintaining the ISC population associated with increased intracellular cholesterol synthesis. Disassociation of ERLIN2 with SCAP by SNX10 deletion enhances the activation of SREBP2, resulting in increased cholesterol biosynthesis. DC-SX029, a small-molecule inhibitor of SNX10, was used to verify the druggable potential of SNX10 for the treatment of patients with CD. Our study provides a strategy for mucosal healing through SREBP2-mediated stemness restoration of ISCs.
Topics: Animals; Humans; Mice; Inflammatory Bowel Diseases; Intestinal Mucosa; Intestines; Sorting Nexins; Stem Cells
PubMed: 37647408
DOI: 10.1126/sciadv.adh5016 -
International Journal of Colorectal... Mar 2014Pelvic radiotherapy may lead to changes of anorectal function resulting in incontinence-related complaints. The aim of this study was to systematically review objective... (Review)
Review
PURPOSE
Pelvic radiotherapy may lead to changes of anorectal function resulting in incontinence-related complaints. The aim of this study was to systematically review objective findings of late anorectal physiology and mucosal appearance after irradiation for prostate cancer.
METHODS
MEDLINE, EMBASE, and the Cochrane library were searched. Original articles in which anal function, rectal function, or rectal mucosa were examined ≥3 months after EBRT for prostate cancer were included.
RESULTS
Twenty-one studies were included with low to moderate quality. Anal resting pressures significantly decreased in 6 of the 9 studies including 277 patients. Changes of squeeze pressure and rectoanal inhibitory reflex were less uniform. Rectal distensibility was significantly impaired after EBRT in 7 of 9 studies (277 patients). In 4 of 9 studies on anal and in 5 of 9 on rectal function, disturbances were associated with urgency, frequent bowel movements or fecal incontinence. Mucosal changes as assessed by the Vienna Rectoscopy Score revealed telangiectasias in 73 %, congestion in 33 %, and ulceration in 4 % of patients in 8 studies including 346 patients, but no strictures or necrosis. Three studies reported mucosal improvement during follow-up. Telangiectasias, particularly multiple, were associated with rectal bleeding. Not all bowel complaints (30 %) were related to radiotherapy.
CONCLUSIONS
Low to moderate quality evidence indicates that EBRT reduces anal resting pressure, decreases rectal distensibility, and frequently induces telangiectasias of rectal mucosa. Objective changes may be associated with fecal incontinence, urgency, frequent bowel movements, and rectal bleeding, but these symptoms are not always related to radiation damage.
Topics: Anal Canal; Defecation; Fecal Incontinence; Humans; Intestinal Mucosa; Male; Pressure; Prostatic Neoplasms; Radiotherapy; Rectum; Telangiectasis; Ulcer
PubMed: 24150230
DOI: 10.1007/s00384-013-1784-8 -
Annales de Dermatologie Et de... 2013Primary anal mucosal melanoma is rare and is associated with a poor prognosis. The observation of a case of anal melanoma at a localized stage in a woman led us to... (Review)
Review
BACKGROUND
Primary anal mucosal melanoma is rare and is associated with a poor prognosis. The observation of a case of anal melanoma at a localized stage in a woman led us to analyze recent data from the literature on therapeutic alternatives.
PATIENTS AND METHODS
A 49-year-old woman presented with a pigmented swelling of the anal margin that had begun three months earlier. Complete local excision of the tumour was performed with the conservation of the anal sphincters. Histological examination revealed SSM mucosal melanoma. Abdominoperineal resection was finally performed because of tumoural invasion of the lateral margins. Staging assessment was normal. Half-yearly MRI monitoring of the pelvis was proposed and at nine months no relapse was seen.
DISCUSSION
The unusual and misleading symptoms often account for the late diagnosis and poor prognosis of anal melanoma. Treatment is not well defined: local excision with conservation of the anal sphincters is recommended as first-line therapy, but the surgical technique is controversial. Abdominoperineal resection is recommended if the surgical margins are invaded, in the case of local recurrence or if the tumour is inaccessible. The place of adjuvant therapies remains to be defined. More recently, the discovery of mutation in c-KIT mucosal melanoma has allowed the use of biotherapy. Our observation underscores the importance of early detection of anal melanoma by all practitioners concerned in view of its aggressiveness and we report the difficulties of therapeutic management in the absence of established guidelines.
Topics: Amputation, Surgical; Anus Neoplasms; Carcinoma, Papillary; Colostomy; Female; Humans; Melanoma; Middle Aged; Mitotic Index; Mucous Membrane; Neoplasm Grading; Neoplasm Invasiveness; Neoplasms, Second Primary; Neuroma, Acoustic; Reoperation; Thyroid Neoplasms
PubMed: 23773742
DOI: 10.1016/j.annder.2013.02.015 -
Diseases of the Colon and Rectum Oct 2016
Topics: Adenomatous Polyposis Coli; Anal Canal; Colonic Neoplasms; Colonic Pouches; Endoscopic Mucosal Resection; Humans; Inflammatory Bowel Diseases; Intestinal Mucosa; Transanal Endoscopic Surgery
PubMed: 27602931
DOI: 10.1097/DCR.0000000000000672 -
Acta Dermato-venereologica Apr 2022
Topics: Anal Canal; Anus Neoplasms; Child; Humans; Mucous Membrane
PubMed: 35166854
DOI: 10.2340/actadv.v102.1177 -
American Journal of Surgery Jul 1993Cicatricial stenosis and mucosal ectropion of the anal canal are disabling complications of anal surgery or disease and are extremely difficult to manage. Perusal of the... (Review)
Review
Cicatricial stenosis and mucosal ectropion of the anal canal are disabling complications of anal surgery or disease and are extremely difficult to manage. Perusal of the literature reveals minimal consensus as to the most successful way to surgically manage patients with these conditions. During a 4-year period, we managed 19 patients who had anal stenosis (n = 14) or anal ectropion (n = 5). Eighteen of these patients had prior anal rectal surgery. We employed a Y-V anoplasty or advancement diamond-shaped pedicle flap and obtained satisfactory to excellent results in all patients. Concurrent lateral internal sphincterotomy was also employed in selected patients who had a fibrotic muscular component contributing to the stenosis. Based on our cohort of patients, we believe the pedicle skin flap technique is slightly superior to the Y-V anoplasty in functional and cosmetic results.
Topics: Anal Canal; Anus Diseases; Cicatrix; Cohort Studies; Constriction, Pathologic; Humans; Intestinal Mucosa; Skin Transplantation; Surgical Flaps
PubMed: 8328629
DOI: 10.1016/s0002-9610(05)80583-5 -
International Journal of Colorectal... Nov 1988
Review
Topics: Anal Canal; Anastomosis, Surgical; Humans; Ileum; Intestinal Mucosa; Postoperative Complications
PubMed: 3058838
DOI: 10.1007/BF01660720 -
Medical Hypotheses Sep 2016Chronic anal fissure is a painful disorder caused by linear ulcers in the distal anal mucosa. Even though it counts as one of the most common benign anorectal disorders,...
Chronic anal fissure is a painful disorder caused by linear ulcers in the distal anal mucosa. Even though it counts as one of the most common benign anorectal disorders, its precise etiology and pathophysiology remains unclear. Current thinking is that anal fissures are caused by anal trauma and pain, which leads to internal anal sphincter hypertonia. Increased anal basal pressure leads to diminished anodermal blood flow and local ischemia, which delays healing and leads to chronic anal fissure. The current treatment of choice for chronic anal fissure is either lateral internal sphincterotomy or botulinum toxin injections. In contrast to current thinking, we hypothesize that the external, rather than the internal, anal sphincter is responsible for increased anal basal pressure in patients suffering from chronic anal fissure. We think that damage to the anal mucosa leads to hypersensitivity of the contact receptors of the anal-external sphincter continence reflex, resulting in overreaction of the reflex. Overreaction causes spasm of the external anal sphincter. This in turn leads to increased anal basal pressure, diminished anodermal blood flow, and ischemia. Ischemia, finally, prevents the anal fissure from healing. Our hypothesis is supported by two findings. The first concerned a chronic anal fissure patient with increased anal basal pressure (170mmHg) who had undergone lateral sphincterotomy. Directly after the operation, while the submucosal anesthetic was still active, basal anal pressure decreased to 80mmHg. Seven hours after the operation, when the anesthetic had completely worn off, basal anal pressure increased again to 125mmHg, even though the internal anal sphincter could no longer be responsible for the increase. Second, in contrast to previous studies, recent studies demonstrated that botulinum toxin influences external anal sphincter activity and, because it is a striated muscle relaxant, it seems reasonable to presume that it affects the striated external anal sphincter, rather than the smooth internal anal sphincter. If our hypothesis is proved correct, the treatment option of lateral internal sphincterotomy should be abandoned in patients suffering from chronic anal fissures, since it fails to eliminate the cause of high anal basal pressure. Additionally, lateral internal sphincterotomy may cause damage to the anal-external sphincter continence reflex, resulting in fecal incontinence. Instead, higher doses of botulinum toxin should be administered to those patients suffering from chronic anal fissure who appeared unresponsive to lower doses.
Topics: Anal Canal; Botulinum Toxins; Botulinum Toxins, Type A; Chronic Disease; Defecation; Feces; Fissure in Ano; Humans; Manometry; Models, Theoretical; Mucous Membrane; Pressure; Reflex; Wound Healing
PubMed: 27515194
DOI: 10.1016/j.mehy.2016.06.005 -
Diseases of the Colon and Rectum Oct 2003Although mucosal plication for rectal prolapse, known as the Gant-Miwa procedure, is described in some English textbooks, it has been infrequently performed in the West.... (Review)
Review
Although mucosal plication for rectal prolapse, known as the Gant-Miwa procedure, is described in some English textbooks, it has been infrequently performed in the West. However, this procedure has been used and developed in conjunction with anal encircling in Japan since the 1960s and is still considered to play a major role in the treatment of rectal prolapse. Certain technical details have been found necessary to ensure the success of the procedure, especially in the technique of anal encircling. For example, the use of Teflon tape and routing relatively deeply and outside the external anal sphincter are necessary. Clinical results show a recurrence rate of 0 to 31 percent with no mortality and almost never any serious complications such as significant bleeding or severe sepsis, which are occasionally encountered in other perineal procedures. Most patients report improved continence after this procedure, and worsening of evacuation is rarely encountered based on our experience. Some physiologic studies have shown improved resting pressure and rectal sensation, which can have a positive influence on the defecatory function. We believe that the Gant-Miwa procedure with anal encircling should be considered as a treatment of choice among perineal procedures for rectal prolapse.
Topics: Anal Canal; Clinical Trials as Topic; Digestive System Surgical Procedures; Humans; Intestinal Mucosa; Rectal Prolapse; Treatment Outcome
PubMed: 14530665
DOI: 10.1097/01.DCR.0000083390.03059.4C