2. ANATOMY OF THE RECTUM
Length : 12cm
Diameter: Upper part is the same as sigmoid colon (4cm) but lower is
dilated (rectal ampulla)
Beginning: Rectosigmoid junction (Sacral promontory)
End: 2.5 cm below and in front of the tip of coccyx.
3. RELATIONS OF THE RECTUM
Male Female
Anterior Bladder Pouch of Douglas
Seminal vesicles Uterus
Ureters Cervix
Prostate Posterior Vaginal wall
Urethra
Lateral Lateral ligament Lateral ligament
Middle rectal artery Middle rectal artery
Obturator Internus m Obturator Internus m
Side wall of the pelvis Side wall of the pelvis
Levator ani Levator ani
Posterior Sacrum, coccyx Sacrum, coccyx
Loose areolar tissue Loose areolar tissue
Facial condensation Facial condensation
Superior rectal artery Superior rectal artery
Lymphatics Lymphatics
4. ARTERIAL SUPPLY
Superior Rectal artery
Middle Rectal Artery
Median Sacral Artery
VENOUS DRAINAGE
Internal & external Venous Plexus
LYMPHATICS
; via the pararectal lymph nodes, which drain into the inferior
mesenteric nodes. Additionally, the lymph from the lower aspect of
the rectum drains directly into the internal iliac lymph nodes.
5. ANATOMY OF ANAL CANAL
Length : 4cm
Extent : from anorectal junction to the anal orifice
Interior :
Upper part
Anal column
Anal valve
Anal sinus
Dentate line
Middle part
Lower part
6. Musculature: External and Internal anal sphincter
Arterial supply: Superior and inferior arteries
Venous Drainage: Rectal venous plexus
Lymphatic Drainage: Internal iliac & Superficial inguinal nodes
7. RECTAL PROLAPSE
A rectal prolapse is the protrusion of mucosal or full-thickness layer of
rectal tissue out of the anus.
There are two main types of rectal prolapse:
Partial thickness – the rectal mucosa protrudes out of the anus
Full thickness – the rectal wall protrudes out the anus
Internal intussusception is the prolapse of the rectum into the distal
rectum or anal canal but without its protrusion outside of the anus
8. PATHOPHYSIOLOGY
The current theories surrounding full prolapse suggest that is a form
of sliding hernia, through a defect of the fascia of the pelvic region.
This may be caused by chronic straining secondary to constipation, a
chronic cough, or from multiple vaginal deliveries.
In contrast, partial thickness prolapses are associated with the
loosening and stretching of the connective tissue that attaches the
rectal mucosa to the remainder of the rectal wall.
This often occurs in conjunction with long standing haemorrhoidal
disease.
11. CLINICAL FEATURES
Patients with a rectal prolapse will typically present with rectal mucus
discharge, faecal incontinence, per rectum bleeding, or with visible
ulceration.
Full thickness prolapses will begin internally and thus can initially
present with a sensation of rectal fullness, tenesmus, or repeated
defecation.
On examination, the prolapse may not always be evident, but can be
identified by asking the patient to strain. A digital rectal examination
should be performed, often on which a weakened anal sphincter is
identified.
For a suspected internal prolapse, defecating proctography and
examination under anaesthesia may be the only means to diagnose
clinically.
12. MANAGEMENT
Conservative management
Conservative management of rectal prolapse is more common in
those unfit for surgery, with minimal symptoms, or in children (as
most prolapses in children will resolve spontaneously).
Initial management often involves increasing dietary fibre and fluid
intake. Minor mucosal prolapses may be banded in clinic, although
this is prone to recurrence.
13. Surgical management
Surgical repair is the only definitive management. The mainstay of
treatments is between the abdominal approach and the perineal
approach:
Perineal approach
The two more commonly performed operations are the Delormes
operation (the prolapsed lining of the rectal mucosa is removed and
the underlying muscle reinforced with plicated sutures)
And also the Altemeier’s operation (resection of the redundant
prolapsed bowel to restore the original anatomy).
16. Abdominal approach.
Performed laparoscopically (most common), robotically, or open, the
procedure will involve a rectopexy, whereby the rectum is mobilised
and fixed onto the sacral prominence via sutures or mesh.
No difference in the post-operative outcomes between abdominal
and perineal procedures, the perineal procedures are preferred in
older patients as they are considered safer operations.
18. PILONIDAL SINUS DISEASE
The term pilonidal is derived from the Latin pilus (hair) and nidus
(nest).
A disease of the inter-gluteal region, characterised by the formation
of a sinus in the cleft of the buttocks.
It most commonly affects males aged 16-30 years .
PATHOPHYSIOLOGY
The most widely accepted theory for pilonidal sinus disease
development is starting from a hair follicle in the intergluteal cleft
becoming infected or inflamed.
19. A PILONIDAL CYST
WITH ITS SINUSTRACT This inflammation obstructs the
opening of the follicle, which extends
inwards, forming a ‘pit’.
A foreign body-type reaction may
then lead to formation of a cavity,
connected to the surface of the skin
by an epithelialised sinus tract.
20. RISK FACTORS
Males with coarse dark body hair.
Siting for prolonged periods, such as lorry drivers or office workers.
Other associated factors
increased sweating, buttock friction, ,obesity, poor hygiene, or local
trauma.
Typically, pilonidal disease does not occur after 45 years of age.
22. N.B
A pilonidal abscess can form when a pilonidal sinus becomes
infected.
This will present as a swollen and erythematous region.
On examination, there will be a fluctuant and tender mass, as well as
systemic features of infection.
The main distinguishing feature compared to a perianal fistula is that
a pilonidal sinus does not communicate with the anal canal
Incase of uncertainty on initial inspection, a rigid sigmoidoscopy or
MRI imaging can be performed to assess for any internal opening of a
tract.
23. MANAGEMENT
Pilonidal disease eases with age and does not always require surgical
management.
Conservative treatment of a pilonidal sinus .
Involves shaving the affected region and plucking the sinus free of
any hair that is embedded.
Any accessible sinuses can be washed out with water to prevent
infection.
Whilst antibiotics can be used in septic episodes, any abscess present
will require surgical drainage.
25. SURGICAL MANAGEMENT
The exact surgical management of a pilonidal sinus is dependant on
whether the disease is acute or chronic.
For any abscess that has developed, an incision and drainage with
washout is required.
It can be difficult to remove the sinus tract in the same operation and
patients may require further surgery.
Treatment of chronic disease is the removal of the pilonidal sinus
tract. There are two main methods:
26. Excision of the tract and laying open the wound, allowing closure by
secondary intention
This has low rates of recurrence yet can take a long time to heal and
has an increased risk of infection.
Excision of the tract, followed by primary closure of the wound
This has higher rates of recurrence and patients may require
reconstructive surgery due to tissue loss from this operation
27. PERIANAL FISTULA
Introduction
A perianal fistula (fistula-in-ano) refers to an abnormal connection
between the anal canal and the perianal skin.
The majority are associated with anorectal abscess formation .
One third of patients with an anorectal abscess have an associated
perianal fistula at the time of presentation.
28. ETIOLOGY
The formation of an perianal fistula typically occurs as a consequence
of a perianal abscess. However, other risk factors for their formation
include:
Inflammatory bowel disease – Crohn’s disease or ulcerative colitis
Systemic diseases – Tuberculosis, diabetes, HIV
History of trauma to the anal region
Previous radiation therapy to the anal region
29. CLINICAL FEATURES
Anal fistulae usually present with either:
Recurrent perianal abcesses
intermittent or continuous discharge onto the perineum, including
mucus, blood, pus, or faeces.
On examination, an external opening on the perineum may be seen;
these can be fully open or covered in granulation tissue.
A fibrous tract may be felt underneath the skin on digital rectal
examination.
32. The Goodsall rule can be used clinically to predict the trajectory of a
fistula tract, depending on the location of the external opening:
External opening posterior to the transverse anal line -fistula tract
will follow a curved course to the posterior midline
External opening anterior to the transverse anal line – fistula tract
will follow a straight radial course to the dentate line.
33. INVESTIGATIONS.
Proctoscopy can be used to visualise the opening of the tract in the
anal canal.
For complex fistula, MRI imaging is often required to visualise the
anatomy of the tract.
34. PARK’S CLASSIFICATION SYSTEM .
Park’s classification system divides anal fistulae into four distinct types:
Inter-sphincteric fistula (most common)
Trans-sphincteric fistula
Supra-sphincteric fistula (least common)
Extra-sphincteric fistula
35.
36. MANAGEMENT.
The definitive management for an anal fistula depends largely on the
cause and site.
If the patient has no symptoms, a conservative approach may be
used.
Surgical Treatment
The most common surgical methods employed are:
A fistulotomy (suitable for superficial disease) involves laying the tract
open by cutting through skin and subcutaneous tissue, allowing it to
heal by secondary intention
37. The placement of a seton (suitable for high tract disease) though the
fistula attempts to bring together and close the tract, passing out at
opening of the perianal skin adjacent to the external opening.
38. It is quite common for patients with complex anal fistulas to require
several repeat procedures over subsequent months.
If the fistula has a low track course (whereby the tract travels
through less subcutaneous tissue and muscle) faecal continence is
rarely impaired post-operatively.
However if the fistula has a high tract course then there is a higher
chance of impairment in continence
40. HAEMORRHOIDS.
Haemorrhoids are defined as an abnormal swelling or enlargement of
the anal vascular cushions.
The anal vascular cushions act to assist the anal sphincter in
maintaining continence.
There are three vascular cushions in the anus, positioned at the 3-, 7-
and 11- o’clock positions (when looked at with the patient in the
lithotomy position, i.e. anterior is 12 o’clock).
When these cushions become abnormally enlarged, they can cause
symptoms and become pathological, termed haemorrhoids.
Have a prevalence peak at age 45-65yrs.
43. CLASSIFICATION OF HAEMORRHOIDS.
Haemorrhoids are classified according to their size:
Classification Description
1st Degree Remain in the rectum.
2nd Degree Prolapse through the anus on defecation
but spontaneously reduce.
3rd Degree Prolapse through the anus on defecation
but require digital reduction.
4th Degree Remain persistently prolapsed.
44. RISK FACTORS
The main risk factors for the development of haemorrhoids are
excessive straining (from chronic constipation), increasing age, and
raised intra-abdominal pressure (such as pregnancy, chronic cough, or
ascites).
Other less common risk factors include pelvic or abdominal masses,
family history, cardiac failure, or portal hypertension.
45. CLINICAL FEATURES
Haemorrhoids typically present with painless bright red rectal
bleeding, commonly after defecation and often seen either on paper
or covering the pan. Importantly, blood is seen on the surface of the
stool, not mixed in.
Other symptoms include pruritus (due to chronic mucus discharge
and irritation), rectal fullness or an anal lump, and soiling (due to
impaired continence or mucus discharge).
Large prolapsed haemorrhoids can thrombose. These are very painful
and these patients frequently present acutely as an emergency
patient.
46. Examination will usually be normal unless the haemorrhoids have
prolapsed. A thrombosed prolapsed haemorrhoid will present as a
purple/blue, oedematous, tense, and tender perianal mass.
47. DIFFERENTIAL DIAGNOSIS
It is important to exclude other causes of rectal bleeding such as
malignancy, inflammatory bowel disease, or diverticular disease.
Other perianal differentials to consider include fissure-in-ano, a
perianal abscess, or fistula-in-ano. So-called “external piles” are
usually just simple skin tags or “sentinel piles” from a fissure-in-ano.
49. INVESTIGATIONS
Proctoscopy is typically performed to confirm the diagnosis. Any
significant or prolonged bleeding or signs of anaemia would warrant a
full blood count and a coagulation screen.
A flexible sigmoidoscopy or colonoscopy may also be considered to
exclude malignancy in certain cases, depending on the patient’s
clinical features.
50. MANAGEMENT
Nearly all haemorrhoids can be managed conservatively, especially if
asymptomatic.
Ensure to provide lifestyle advice, such as increasing daily fibre and
fluid intake to avoid constipation, prescribing laxatives if necessary.
Topical analgesia (such as lignocaine gel) may also be required for
pain relief; avoid oral opioid analgesia as this can compound any
constipation and worsen symptoms.
Often patients are not too troubled by the symptoms and simply
want reassurance that the cause of the bleeding is not sinister, and
often this is sufficient
51. NON-SURGICAL
Symptomatic 1st and 2nd degree haemorrhoids can be treated with
rubber-band ligation (RBL).
This involves the haemorrhoid being drawn into the end of a suction
gun and a rubber band placed over the neck of the haemorrhoid.
This can be done either in a clinic setting or in theatre.
The main complications of this procedure include recurrence, pain (if
the band is mistakenly placed below the dentate line), and bleeding.
53. SURGICAL
Haemorrhoidal artery ligation (HAL) is one surgical option for 2nd or
3rd degree haemorrhoids, with equivocal effectiveness to other
interventions (including RBL).
Around 5% of patients with haemorrhoids will eventually need a
haemorrhoidectomy.
This is indicated if patients are symptomatic and not responding to
conservative therapies, yet unsuitable for banding or injection (mainly
3rd degree and 4th degree).
Typically this is either as a stapled haemorrhoidectomy or Milligan
Morgan haemorrhoidectomy.
56. ANORECTAL ABSCESS.
Introduction
An anorectal abscess refers to a collection of pus in the anal or rectal
region. They are more common in men than in women and have high
rates of recurrence.
Pathophysiology
Anorectal abscess are though to be caused by plugging of the anal
ducts, the ducts that drain the anal glands in the anal wall, helping to
ease the passage of faecal matter through mucus secretion.
Blockage of an anal duct results in fluid stasis, which will lead to
infection.
Common causative organisms include E. coli, Bacteriodes spp., and
Enterococcus spp..
57. CLASSIFICATION
The anal glands are located in the intersphincteric space (between
the internal and external anal sphincters).
Therefore ,infection from the glands here spreads to adjacent areas.
Anorectal abscesses are thus categorised by the area in which they
occur
Perianal*
Ischiorectal
Intersphincteric
Supralevator
The perianal area is the most common site of abscess formation
59. CLINICAL FEATURES
Anorectal abscesses present with pain in the perianal region, which
becomes exacerbated when sat down.
Other symptoms include localised swelling, itching, or discharge.
Severe abscesses may present with systemic features* such as fever,
rigors, general malaise, or features of sepsis.
On examination, there will be a erythematous, fluctuant, tender
perianal mass which may be discharging pus or have surrounding
cellulitis.
60. Deeper abscesses may not have any obvious external signs, however
produce severe tenderness on digital rectal exam, therefore require a
further examination under anaesthesia for full assessment.
Complicated, unclear, or chronic disease may require additional
imaging, either a CT or MRI scan.
*These features are more likely in patients who are
immunocompromised or those with ischiorectal abscesses.
62. MANAGEMENT
Patients should be started on antibiotic therapy, as guided by local
protocol, and provided with sufficient analgesia.
The main management for anorectal abscesses is with an incision
and drainage procedure, which should always be performed under
general anaesthetic.
These can be left to heal by secondary intention.
Once drained, proctoscopy should be performed to check for the
presence of any identifiable fistula-in-ano.
63. If a fistula is identified, the insertion of a seton can be considered by
experienced surgeons.
However this should only be performed if the tract is clearly
identifiable with minimal probing.
Limited data has suggested that use of post-operative antibiotics
following drainage of anorectal abscess may lower the risk of fistula
formation.
64. ANAL FISSURE
Tear in the mucosal lining of the anal canal.
Most commonly due to trauma from defecation of hard stool.
It can be classified according to its duration:
Acute – present for <6 weeks
Chronic – present for >6 weeks
Anal fissures can also be categorised by whether they are primary (no
underlying disease) or secondary (underlying disease e.g
inflammatory bowel disease).
65. • RISK FACTORS
Anal fissures are usually caused by inflammation or trauma to the
anal canal.
The major risk factors include:
Constipation
Dehydration
Inflammatory bowel disease
Chronic diarrhoea
CLINICAL FEATURES
The most common presenting feature of an anal fissure is intense
pain post-defecation, which can last several hours.
66. Pain can be far out of proportion to the size of the fissure. Other
associated symptoms may include bleeding (commonly bright red
blood on wiping) or itching, both typically post-defecation.
On examination, fissures can be visible and / or palpable (albeit very
painfully) on digital rectal examination.
Most fissures present in the posterior midline (90% cases); anterior
fissures are more likely to in females or if an underlying cause is
present*.
Often patients will refuse a digital rectal examination due to the
intense pain
Examination under anaesthesia (EUA) may be necessary for diagnosis
67. Fissures within the anal canal can then usually be identified upon
proctoscopy.
The differential diagnoses include haemorrhoids, Crohn’s disease,
ulcerative colitis, or anal cancer.
Multiple fissures or anteriorly located fissures are more likely to be
due to an underlying cause and require further investigations (if no
known cause is apparent)
69. MANAGEMENT
Medical Management.
The medical management of an anal fissure involves reducing risk
factors and providing adequate analgesia.
The majority of patients do not require surgery.
Measures such as increasing fibre and fluid intake will help.
Stool softening laxatives (such as Movicol or Lactulose) can be
trialled if there is no change in stool following initial conservative
management.
Topical anaesthetics, such as lidocaine, or hot baths can help to relax
the anal sphincter and also help the healing process.
70. If patients are still symptomatic, the next line of management is GTN
cream or diltiazem cream.
This increases the blood supply to the region and relaxes the internal
anal sphincter, putting less pressure on the fissure, promoting healing
and reducing pain.
SURGICAL MANAGEMENT
Surgical therapy is reserved for chronic fissures where medical
management has failed to resolve the symptoms.
Botox injections can be given into the internal anal sphincter, to
relax and promote healing.
A lateral sphincterotomy can be performed, involving division of the
internal anal sphincter muscle.
71. Recurrence of anal fissures post-surgery is between 1-5%
But studies have shown that the majority of these recurrence
patients are those with an underlying predisposition to the condition.
The main complication is faecal incontinence.
73. Anal cancer is a relatively rare cancer of the gastrointestinal tract,
accounting for around 4% of colorectal cancers.
The majority of anal cancers are squamous cell carcinomas, arising
from below the dentate line.
The remainder (~10%) are adenocarcinomas arise from the upper
anal canal epithelium and the crypt glands.
Rarer anal tumours include melanomas and anal skin cancers.
A pre-cancerous condition, anal intraepithelial neoplasia (AIN), may
precede the development of invasive squamous anal carcinoma.
74. ANAL INTRAEPITHELIAL NEOPLASIA.
Anal intraepithelial neoplasia (AIN) is a precancerous condition that
can affect either the perianal skin or anal canal, linked to the
development of squamous cell carcinoma.
It is strongly linked to infection with the human papilloma virus
(HPV).
The grading of AIN is dependent on the degree of cytological atypia
and the depth of that atypia in the epidermis.
High-grade AIN (grade 2 or 3) is premalignant and may progress to
invasive cancer.
75.
76. RISK FACTORS
The risk factors for developing anal cancer include HPV infection
(accounts for 80-90% of cases, especially HPV-16 and HPV-18), HIV
infection, increasing age, smoking, immunosuppression, or Crohn’s
disease.
Clinical Features
The main symptoms of anal cancer are rectal pain or rectal bleeding,
occurring in around half of patients.
Other symptoms may include anal discharge, pruritus, or the
presence of a palpable mass.
Perianal infection and fistula-in-ano can be seen in locally invasive
disease.
If the anal sphincters have been involved, faecal incontinence and
tenesmus can also occur.
77. On examination, the perineal and perianal regions should be
screened for any ulceration or the presence of wart-like lesions.
Any mass felt on PR exam should be documented along with its
distance from the anal verge and the proportion of anal
circumference involved.
The inguinal lymph nodes should be examined for any
lymphadenopathy*.
*Lymph from the area below the dentate line drains to the superficial
inguinal nodes, whereas the anal canal and rectum above the dentate
line drain into the mesorectal, para-aortic, and paravertebral nodes.
78. DIFFERENTIAL DIAGNOSIS
The main benign differentials include haemorrhoids, anal fissure,
fistula-in-ano, and anal warts, whilst malignant disease differentials
include a low rectal cancer or a skin cancer.
INVESTIGATIONS
Initial Investigations
Following initial examination, proctoscopy should be performed to
obtain a better initial assessment of the anal canal.
All patients with suspected anal cancer should then undergo
examination under anaesthetic (EUA).
An EUA allows for much better assessment for tumour size and
invasion of local structures, as well as allowing a biopsy to be taken
for histological confirmation.
79. In women, a smear test can be performed to exclude any cervical
intraepithelial neoplasia (CIN) and any further biopsies if signs of
vulval intraepithelial neoplasia (VIN) are present.
Consider a HIV test, especially those with risk factors.
IMAGING
Once the diagnose has been confirmed by biopsy, further staging
investigations are required:
USS-guided Fine Needle Aspiration (FNA) of any palpable inguinal
lymph nodes
CT thorax-abdomen-pelvis for distant metastases
MRI Pelvis to assess the extent of local invasion (T stage)
81. MANAGEMENT
A multidisciplinary approach must be used in the management of
anal cancer, including oncologists, general surgeons, radiologists, and
specialist nurses.
Chemo-radiotherapy is often the first choice treatment for anal
tumours (expect from T1N0 carcinomas, whereby wide local excision
surgical treatment is usually sufficient).
Treatment is usually via external beam radiotherapy to the anal canal
and inguinal lymph nodes, combined with dual-chemotherapy agents,
such as mitomycin C and 5-fluorouracil.
84. SURGICAL MANAGEMENT.
Surgical excision is usually reserved for management of advanced
disease, after failure of chemoradiotherapy, or in early T1N0
carcinomas.
The majority of patients requiring surgical intervention for anal
cancer will receive an abdominoperineal resection (APR), yet for
some a posterior or total pelvic exenteration is required.
Patients should be reviewed every 3–6 months for a period of 2
years, before having reviews spaced out further.
Most recurrences occur in the first 3 years following surgery and will
tend to relapse locally and regionally rather than have spread distant.
85. COMPLICATIONS.
Chemoradiation-related pelvic toxicity is the most common short
term complication, which can present with dermatitis, diarrhoea,
proctitis, and/or cystitis.
Longer term, patients may develop fertility issues, faecal
incontinence, vaginal dryness, erectile dysfunction, and rectovaginal
fistula
86. PROGNOSIS
Prognosis is related to the initial staging of the tumour.
Tumour Stage 5 Year Survival (%)
I 69.5
II 61.8
IIIa 45.6
IIIb 39.6
IV 15.3