Shape and volume of internal anal sphincter showed by three-dimensional anorectal ultrasonography

Sboarina, Andrea; Minicozzi, Annamaria; Segattini, Carlo; Leopardi, F; Lombardo, Fábio; Passeri, V.; Scudo, G.; Bencivenga, Maria; Fenzi, Alberto; Cordiano, Claudio

doi:10.1016/j.ejrad.2011.04.024

Cited by 8 publications

(4 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The posterior view shows the LAM but is unable to identify the subcutaneous part of the EAS Table 2 Macroscopic observations of the external anal sphincter in the lateral anal wall: a comparison between Japanese and German cadavers intermed intermediate morphologies between the J-shaped muscle and the complete absence of J (absent-J) * The absent-J was more frequently seen in Japan (7 + 6) in elderly Japanese than elderly White European individuals (p < 0.05). Clinical imaging has shown age-dependent differences in the sizes of the anal sphincters [1,7,26,30,32]. Using endoanal magnetic resonance imaging (a MRI of which coil inserted into the anal canal), only one of them [30] identified a border between the IAS and EAS, i.e., a fibromuscular band termed the longitudinal anal muscle.…”

Section: Discussionmentioning

confidence: 99%

A missing distal complex of the external and internal anal sphincters: a macroscopic and histologic study using Japanese and German elderly cadavers

Ishiyama¹,

Kim

Chai

et al. 2020

Surg Radiol Anat

View full text Add to dashboard Cite

The lower margin of the internal anal sphincter (IAS) is considered to lie on a J-shaped, subcutaneous part (SCP) of the external anal sphincter (EAS). The lower IAS is united with the J-shaped SCP to form a smooth-striated muscle complex. In the first part of this study, we ensured the presence of the J-shaped EAS in the lateral wall of the anal canal from 12 near-term fetuses. Second, in the lateral anal wall, the examination of the longitudinal section from 20 male and 24 female Japanese cadavers (72-95 years-old) demonstrated that the J-shaped EAS was lost in 15 (34%) due to the very small SCP. Third, we demonstrated that the J-shaped EAS was restricted in the latera anal wall using longitudinal histological sections of the anal canal from 11 male Japanese cadavers (75-89 years-old). Therefore, a site-dependent difference in the IAS-EAS configuration was evident. Finally, we compared a frequency of the lost J-shape between human populations using 10 mm-thick frontal slices from 36 Japanese and 28 German cadavers. The two groups of cadavers were compatible in age (a 0.2-years' difference in males). The macroscopic observations revealed that the J-shaped EAS was absent from 13 (36%) Japanese and six (20%) German specimens, suggesting that the SCP degeneration occurred more frequent in elderly Japanese than elderly German individuals (p < 0.05). The distal IAS-EAS complex seemed to push residual feces out of the anal canal at a transient phase from evacuation to closure. The absence might be the first sigh of anal dysfunction.

show abstract

Section: Discussionmentioning

confidence: 99%

A missing distal complex of the external and internal anal sphincters: a macroscopic and histologic study using Japanese and German elderly cadavers

Ishiyama¹,

Kim

Chai

et al. 2020

Surg Radiol Anat

View full text Add to dashboard Cite

show abstract

“…The internal anal sphincter (IAS) is the downward continuation of the circular smooth muscle of the rectum and terminates with a rounded edge approximately 1 cm proximal to the distal aspect of the external anal sphincter. 3D imaging studies of this muscle demonstrate the overall volume does not vary according to gender, but the distribution is different with women tending to have a thicker medial/distal internal anal sphincter [11]. Overall, the IAS was found to be approximately 2 mm in thickness and 35 mm in length.…”

Section: Internal Anal Sphinctermentioning

confidence: 90%

“…Anal crypts are connected to underlying anal glands which are the presumed source of sepsis in the majority of anorectal abscesses and fistula. On average, there are six anal glands surrounding the anal canal (range, [3][4][5][6][7][8][9][10][11][12] [6,8,9], and they tend to be more concentrated in the posterior quadrants. More than one gland may open into the same crypt, and some crypts may not be connected to anal glands.…”

Section: Anal Canal Epitheliummentioning

confidence: 99%

Anatomy and Embryology of the Colon, Rectum, and Anus

Carmichael

Mills

2021

The ASCRS Textbook of Colon and Rectal Surgery

View full text Add to dashboard Cite

The dentate line represents a true division between embryonic endoderm and ectoderm.• The location of the anterior peritoneal reflection is highly variable and can be significantly altered by disease such as rectal prolapse. • The right and left ischioanal space communicate posteriorly through the deep postanal space between the levator ani muscle and anococcygeal ligament. • The junction between the midgut (superior mesenteric artery) and the hindgut (inferior mesenteric artery) leads to a potential watershed area in the area of the splenic flexure. • There is a normal, three-stage process by which the intestinal tract rotates during development beginning with herniation of the midgut followed by return of the midgut to the abdominal cavity and ending with its fixation.

show abstract

“…Because of controversy in description of the DVF, the anterior plane of dissection in TME is not clear. [4][5][6] Some surgeons believe that dissection should be posterior to the fascia, while others propose splitting the layers of fascia, and some adopt dissection anterior to the DVF. Suboptimal surgery with poor oncological and functional outcome can result from inappropriate anterior dissection during TME secondary to confusion when identifying the anterior plane.…”

Section: Introductionmentioning

confidence: 99%

Understanding the Anatomy of the Denonvilliers Fascia: Review Article

Alessa

2021

Journal of Coloproctology

View full text Add to dashboard Cite

The postoperative outcome of rectal cancer has been improved after the introduction of the principles of total mesorectal excision (TME). Total mesorectal excision includes resection of the diseased rectum and mesorectum with non-violated mesorectal fascia (en bloc resection). Dissection along the mesorectal fascia through the principle of the “holy plane” minimizes injury of the autonomic nerves and increases the chance of preserving them. It is important to stick to the TME principle to avoid perforating the tumor; violating the mesorectal fascia, thus resulting in positive circumferential resection margin (CRM); or causing injury to the autonomic nerves, especially if the tumor is located anteriorly. Therefore, identifying the anterior plane of dissection during TME is important because it is related with the autonomic nerves (Denonvilliers fascia). Although there are many articles about the Denonvilliers fascia (DVF) or the anterior dissection plane, unfortunately, there is no consensus on its embryological origin, histology, and gross anatomy. In the present review article, I aim to delineate and describe the anatomy of the DVF in more details based on a review of the literature, in order to provide insight for colorectal surgeons to better understand this anatomical feature and to provide the best care to their patients.

show abstract

Shape and volume of internal anal sphincter showed by three-dimensional anorectal ultrasonography

Cited by 8 publications

References 10 publications

A missing distal complex of the external and internal anal sphincters: a macroscopic and histologic study using Japanese and German elderly cadavers

A missing distal complex of the external and internal anal sphincters: a macroscopic and histologic study using Japanese and German elderly cadavers

Anatomy and Embryology of the Colon, Rectum, and Anus

Understanding the Anatomy of the Denonvilliers Fascia: Review Article

Contact Info

Product

Resources

About