Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st Year, 2nd Year, 3rd Year and Final year Surgery 49 Rectum Anatomy And Physiology Clinical Features PPT-Powerpoint Presentations and lecture notes
Rectum - Anatomy and Physiology,
Clinical features of Rectal disease,
Examination of Rectum, Rectal prolapse
Dept Of Surgery
Anatomy and Physiology
? The rectum is approximately 12 to 15 cm in length.
? Three distinct submucosal folds, the valves of Houston, extend
into the rectal lumen.
? At S4, the rectosacral fascia (Waldeyer's fascia) extends
forward and downward and attaches to the fascia propria at
the anorectal junction.
? Anteriorly, Denonvil iers' fascia separates the rectum from the
prostate and seminal vesicles in male and from the vagina in
female.
? The dentate or pectinate line marks the transition point between
columnar rectal mucosa and squamous anoderm.
? The 1 to 2 cm of mucosa just proximal to the dentate line shares
histologic characteristics of columnar, cuboidal, and squamous
epithelium and is referred to as the anal transition zone.
? The dentate line is surrounded by longitudinal mucosal folds, known
as the columns of Morgagni, into which the anal crypts empty. These
crypts are the source of cryptoglandular abscesses
Arterial supply
? The superior rectal artery arises from the terminal branch of
the inferior mesenteric artery and supplies the upper rectum.
? The middle rectal artery arises from the internal iliac artery
? The inferior rectal artery arises from the internal pudendal
artery, which is a branch of the internal iliac artery.
? A rich network of collaterals connects the terminal arterioles
of each of these arteries, thus making the rectum relatively
resistant to ischemia
Venous drainage
? The superior rectal vein drains into the portal system via the
inferior mesenteric vein.
? The middle rectal vein drains into the internal iliac vein.
? The inferior rectal vein drains into the internal pudendal vein,
and subsequently into the internal iliac vein.
? A submucosal plexus deep to the columns of Morgagni forms
the hemorrhoidal plexus and drains into all three veins
Lymphatic drainage
? Paral els the vascular supply
? Lymphatic channels in the upper and middle rectum drain
superiorly into the inferior mesenteric lymph nodes
? Lymphatic channels in the lower rectum drain both
superiorly into the inferior mesenteric lymph nodes and
lateral y into the internal iliac lymph nodes.
Indications for Rectal Examination
? Assessment of the prostate (particularly symptoms of outflow
obstruction).
? When there has been rectal bleeding (prior to proctoscopy,
sigmoidoscopy and colonoscopy).
? Constipation.
? Change of bowel habit.
? Problems with urinary or faecal continence.
? In exceptional circumstances to detect uterus and cervix
(when vaginal examination is not possible).
Procedure
? The finger is then moved through 180?, feeling the walls of the
rectum.
? With the finger then rotated in the 12 o'clock position, helped
usually by the examiner bending knees in a half crouched
position and pronating the examining wrist, the anterior wall
can be palpated.
? Rotation facilitates further examination of the opposing the
walls of the rectum. In men, the prostate will be felt anteriorly.
In women, the cervix and a retroverted uterus may be felt with
the tip of the finger.
? It is important to feel the walls of the rectum throughout the
360?. Small rectal wall lesions may be missed if this is not done
carefully.
Examination of the Prostate Gland
? Normal size is 3.5 cms wide, protruding about 1
cm into the lumen of the rectum.
? Consistency: it is normal y rubbery and firm with a
smooth surface and a palpable sulcus between
right and left lobes.
? There should not be any tenderness.
? There should be no nodularity.
External Inspection
? Skin disease.
? Skin tags
? Genital warts
? Anal fissures
? Anal fistula
? External haemorrhoids
? Rectal prolapse
? Skin discolouration with Crohn's disease
? External thrombosed piles
Internal Inspection
? Simple piles (but best examined at
proctoscopy)
? Rectal carcinoma
? Rectal polyps
? Tenderness
? Diseases of the prostate gland
? Malignant or inflammatory conditions of the
peritoneum (felt anteriorly)
Contraindications
? Imperforate Anus
? Unwilling patient
? Immunosuppressed patient
? Absence of anus following surgical excision
? Stricture
? Moderate to severe anal pain
? Prolapsed thrombosed internal hemorroids
Rectal Prolapse
? Also termed `rectal procidentia'
? Protrusion of the rectum beyond the anus
? 6:1 female to male predominance
? Peak incidence is in the 6th -7th decades of life
Risk factors:
? Chronic constipation
? Chronic diarrhea
? Mental retardation
? Female sex
Anatomic abnormalities seen in patients with
rectal prolapse
? Deep rectovaginal or rectovesical pouch
? Lax pelvic floor musculature
? Failure of normal relaxation of the external sphincter
? Redundant sigmoids
? Pudendal nerve injury
Classification of rectal prolapse
? Partial: prolapse of rectal mucosa only
? Complete: prolapse with all layers
? Grade 1: occult prolapse
? Grade 2: prolapse to but not through anus
? Grade 3: any protrusion through anus
Presentation
Primary complaint is their rectum coming out
May mistake it as haemorrhoids
? Tenesmus
? Bleeding
? Mucus discharge
? Constipation
? Fecal incontinence
? Sensation of incomplete evacuation
Complications of prolapse
? Ulceration
? Strangulation
? Urinary and fecal incontinence
? Spontaneous rupture with evisceration
Evaluation
? Rectal prolapse can be incarcerated and
represent a surgical emergency
? So, rule out incarceration
? History
? When does it occur?
? Associated symptoms
? Pts general health and associated medical problems
? Association with psychiatric illness
? Physical exam
? Colonoscopy
? Rule out additional pathology, such as a neoplasm
which may be causing the prolapse
? Anorectal manometry and pudendal nerve terminal
motor latency (PNTML) should be considered in
patients with fecal incontinence
? Patients with constipation should undergo colonic
transit studies
? Dynamic pelvic floor MRI
? Endorectal ultrasound
? Cinedefecography
Nonoperative Management
? High fiber diet
? Biofeedback may be helpful for patients with internal
intussusception and inappropriate pelvic floor
contraction
? Does not play a significant role in the treatment of
rectal prolapse
Surgery
Abdominal approach
? The first step is mobilization of the rectum
? Involves dissection between the mesorectum and the
presacral fascia
? Mobilization is taken down to the level of the levators
? Anterior mobilization should be taken to the level of the
vagina or seminal vesicles
Rectopexy
Ripstein procedure
? First described in 1952
? After mobilization of the rectum is undertaken, a piece of
prosthetic mesh is placed around the anterior wal of the
rectum
? Done at the level of the peritoneal reflection
? low recurrence rates: 0-9.6%
? high rate of complications: up to 52%
? One of the more disastrous complications is mesh erosion
into the rectum
Wells' posterior Ivalon rectopexy
? First described in 1959
? Low recurrence rates: 3.0-6.0%
? Morbidity rate of up to 19%
? Complications: mesh erosion resulting in fistula
formation
Suture rectopexy
In 1959, Cutait proposed suture rectopexy
without the implantation of mesh.
Suture rectopexy with resection
? First described by Frykman in 1955
? Combined resection with rectopexy
? Recommended for rectal prolapse patients with a long, redundant
sigmoid colon
? It has decreased rates of post-operative constipation
? For patients with a long, redundant sigmoid and significant pre-op
constipation, it is the procedure of choice
? Recurrence rates of 0-5%
? Additional theoretical advantage of prevention of sigmoid volvulus
? Complication rates shown to be similar to rectopexy alone
Laparoscopy
? Similar recurrence rates and functional
outcomes compared to similar open procedures
? Longer OR times but shorter hospital stays
? Cost analysis shows decreased costs due to
shorter hospital stays
Anal encirclement
procedure (1871)
Commonly referred to
as the Thiersch
procedure
Mucosal sleeve
resection (1900)
Commonly referred to as
the Delorme procedure
Perineal
rectosigmoidectomy
? differs from the
Delorme procedure in
that it is full thickness
Conclusion
? Rectal prolapse is a complicated disease
process due to a combination of factors
? Thorough pre-operative workup is required to
determine the appropriate procedure
This post was last modified on 08 April 2022