Perianal Surgery Flashcards
What is the anatomy of the rectum?
- 12cm
- Sacral promontory to levator ani muscles
- The 3 tenia coli fuse around the rectum to form a
continuous muscle layer
What is the anatomy of the anal canal?
- 4cm
- Levator ani muscle to anal verge
- Upper 2/3 of canal
Lined by columnar epithelium
Insensate
Superior rectal artery and veni
Internal iliac nodes
- Lower 1/3 canal Lined by squamous epithelium Sensate Middle and inf rectal arteries and veins Superficial inguinal nodes
Dentate line = squamomucosal junction
White line = where anal canal becomes true skin.
What are the anal sphincters
Internal - thickening of rectal smooth muscle. Involuntary control.
External: Three rings of skeletal muscle
- Deep
- Superficial
- Subcut
Under voluntary control
- Anorectal ring - Deep segment of external sphincter which is continuous with puboretalis muscle (part of levator ani)
- Palpable on PR ~5cm from the anus
- Demarcates junction between anal canal and rectum
- Must be preserved to maintain continence.
What is a perianal haematoma?
Subcut bleeding from a burst venule caused by straining or the passage of hard stool
Also called an external pile.
Presents
- tender blue lump at the anal margin
- Pain worsened by defecation or movement
Management
- Analgesia + Spontaneous resolution
- Evacuation under LA
What is proctalgia fugax?
Young, anxious man
Crampy anorectal pain worse @ night.
Unrelated to defection
Associated with trigeminal neuralgia
Reassurance
GTN cream
Perineal warts?
SEen in MSM
Condylomata accuminata
- HPV
- Manage: podophyllin pain, cryo, surgical excision
- Condylomata lata
Syphilis - Manage: penicillin
What is pruritis ani caused by?
50% idiopathic Poor hygiene Haemorrhoid Anal fissure Anal fistula Fungi, worms Crohns Neoplasia
What are haemorrhoids?
Disrupted and dilated anal cushions
Pathophysiology
- Anal cushion: mass of spongy vascular tissue
- Positioned @ 3, 7, 11 O-clock.
Where the three major arteries that feed the vascular plexuses enter the anal canal.
Gravity, straining –> engorgement and enlargement of anal cushions.
Hard stool disrupts connective tissue around cushions
- Cushions protrude and can be damaged by hard stool
- -> bright red (capillary bleeding)
- Haemorrhoid arise above dentate line so not painful.
May ulcerate if gripped by anal sphincter.
Causes of haemorrhoids?
Constipation with prolonged straining Venous congestion may contribute - Pregnancy - Abdominal tumour - Portal HTN
Classifications of haemorrhoids?
1st degree: never prolapsed
2nd degree: prolapse on defection but spontaneously reduce
3rd: prolapse on defecation but require digital reduction
4th: remain permanently prolapsed.
Symptoms of haemorrhoids?
Fresh painles PR bleeding
- Bright red
- On paper, on stool, may drip into pan
- Pruritis ani
- Lump in perianal area
- Severe pain = thrombosis
Examination of haemorrhoids?
- Full abdo exam, palpating for masses
- Inspect perianal area: masses, rectal bleeding
- DRE: can’t palpate piles unless thrombosed
rigid sig to identify higher rectal pathology - Proctoscopy (also allows Rx)
Differential for haemorrhoids?
Perianal haematoma
Fissure
Abscess
Tumour
Management of haemorrhoids?
Conservative
- Increased fibre and fluid intake
- Stop straining at stool
Medical management of haemorrhoids?
Topical preparations
- Anusol: hydrocortisone
- topical analgesics
Laxatives: lactulose, Fybogel
Intervention of haemorrhoids?
Injection with sclerosant 0 5% phenol in Almond oil
- above dentate line. Can cause impotence and prostatitis.
Barron’s banding –> thrombosis and separation. Superior to injection sclerotherapy.
- SE: bleeding, infection
Cryotherapy
- SE: watery discharge post-procedure
Infra-red coagulation
What are the surgical options for haemorrhoids?
- Excision of piles + ligation of vascular pedicles
- Lactulose + metronidazole 11 week pre-op
- Discharge with laxatives post-op
- SE: bleeding, stenosis.
How do you manage thrombosed piles?
Significant pain, examination reveals a purplish oedematous, tender subcut perianal mass.
If patient presents within 72hrs then referral should be considered for excision.
- Analgesia
- Ice-packs
- Stool softener
- Bed rest with elevated foot of bed
- Pain usually resolves in 2-3 weeks
- Haemorrhoidectomy is not usually necessary.
What is an anal fissure?
Tear of squamous epithelial lining in lower anal canal
Causes of anal fissure?
Mostly trauma 2ndry to passage of hard stool
- associated with constipation
- Spasm of internal anal sphincter contributes to pain and –> ischaemia + poor healing.
- Commoner in women
Rare causes of anal tissue?
Multiple + lateral fissures
- Crohns
- Herpes
Anal Ca
Presentation of anal fissure?
Intense anal pain
- Especially on defecation
- may prevent pt from passing stools
- Fresh rectal bleeding
On paper mostly.
Examination of anal fissure?
PR often impossible
Midline ulcer is seen
- Usually posterior @ 6 O’clock
- may be anterior
May be mucosal tag –> Sentinel pile (usually posterior @ 6 oclock)
Groin LNs suggest complicating factor: e.g HIV.
Management of anal fissure?
If fissure recurrent, chronic or difficult to manage the patient required EUA.
Conservative management of anal fissure?
Soaks in warm bath
Toileting advice
Dietary advice: increased fibre and fluids
Medical management of anal fissure?
Laxatives: lactulose + fybgel
Topical –> resolution in 75%
- Lignocaine
For chronic anal fissure (>6 weeks)
- GTN
- Diltiazem
if topical GTN is not effective after 8 week refer to consider surgery or
Botulinum injection
Surgical management of anal fissure?
Division of internal anal sphincter @ 3 o’clock
Pre-op anorectal US + mannometry
= Sphincterotomy
Complications
- Minor faecal/flatus incontinence
- Perianal abscess
What is a fistula in ano?
- Abnormal connection between ano-rectal canal and skin.
What is the pathogenesis of fistula in ano?
Occur 2ndry to perianal sepsis
- Blockage of intramuscular glands –> abscess
- Abscess discharges to form
Associated with
- Crohns
- Diverticular disease
- Rectal Ca
- Immunosuppression
Classifications of fistula in ano?
high: cross sphincter muscles above dentate line
Low: Don’t cross sphincter muscles above dentate line
What is Goodsall’s rule?
Determins path of fistula tract
- Fistula anterior to anus tracks in a straight line.
- Fistula postioer to anus will always have internal opening at the 6 o-clock position –> curved trck.
Presentation of fistula?
Persistent anal discharge
Perianal pain or discomfort
Examination of fistula?
May visualise external opening: may be pus
Induration around the fistula on DRE
Proctoscopy may reveal internal opening.
Investigations of fistula?
MRI
Endoanal US
Management of fistula?
Extent of fistula must first be delineated by probing fistula EUA?
LOw fistula?
Fistulotomy and excision
- Laid open to heal by 2nd intention.
High fistula ?
- Fistulotomy could damage the anorectal ring
- Suture - a seton - passed through fistula and gradually tightened over months.
- Stimulates fibrosis of tract
- Scar tissue hold sphincter together.
What is peri-anal sepsis/Abscess?
Anal gland blockage –> infection –> abscess
E.g coli, bacterioids. Staph A
May develop from skin infections
- E.g sebaceous gland or hair follicle
Associations of anal absces?
Perianal: 45% - Discrete local red swelling close to anal verge - Ischiorectal: <30% Systemic upset Extermely painful on DRe
- Interspincteric/intermuscular: >20%
- Pelvirectal/supralevator: ~5%
Systemic upset
Bladder irritation
Diabetes/malignancy associated.
Presentation + examination of anal abscess?
Throbbing perianal pain
- Worse on sitting
Occassionally a purulent anal discharge
Spiking fever/temperature
Perianal mass or cellulitic area
Fluctuant mass on PR
Septic signs, fever, tachycardia
Management of perianal abscess /
ABx may suffice if management instigated v.early in course.
Most cases require EUA with I+D. (incision and draining)
- Wound packed
- heals by 2nd intention
- Daily dressing for 7-10 days.
Look for an anal fistula which complicates ~30% of abscess.
What is a pilonidal sinus?
Definition -
- Pilonidal - nest of hair
- Sinus: blind ending tract, lined by epithelial or granulation tissue. Opens an epithelial surface.
How does a pilonidal sinus form?
Hair works its way benath skin –> foreigh body reaction –> formation of abscess.
Usually occur in the natal cleft.
Risk factors of pilonidal sinus
M>F = 4:1
- geo: Mediterranean, middle east, asian
- Often overweight with poor personal hygiene
- Occupations with lots of sitting: e,g truck drivers
Presentation of pilonidal sinus?
Persistent discharge or purulent or clear fluid
Recurrent pain
Abscesses
Management of pilonidal sinus?
Conservative
- Hygiene advice
- Shave/remove hair from affected areas
Surgical - Incision + drainage of abscesses - Elective sinus excision Methylene blue to outline tract Recurrence in 4-15%.
Anal carcinoma?
Uncommon: 250-300 cases yr in the UK.
Pathology
- 80% - SCC (also melanoms, adenocarcinomas)
Anal margin tumours
- Well differentiated keratinising lesions
- Commoner in men
- Good prognosis
Anal canal tumour
- Arise above dentate line
- Poorly differentiated, non-keratinising
- Commoner in women
- Poor prognosis
Spread
- Above dentate line –> Internal iliac nodes
- Below dentate line –> inguinal nodes
Aetiology of anal carcinoma?
HPV (16,18, 31, 33) is important factor - Most important. - Increased incidence in MSM Increased incidence if perianal warts. - Smoking is also a risk factor - IMmunosupression
Presentation of anal carcinoma?
- Perianal pain and bleeding
- Pruritus ani
- Faecal incontinence
- -> 70% have sphincter involvement @ presentation
- May have rectovaginal fistula
Palpable lesion in only 25%
± palpable inguinal nodes
Investigations for anal carcinoma?
Low Hb
Endoanal US
Rectal EUA + biopsy
CT/MRI: assess pelvic spread
Management of anal carcinoma?
Chemoradiotherapy: Most pts
- 50% 5yrs
Surgery
- Reserved for:
Tumours that fail to respond to radiotherapy
GI obstruction
Small anal margin tumours without sphincter involvement.
What is rectal prolapse?
Protrusion of rectal tissue through anal canal
Type 1 prolapse?
Mucosal prolapse
- Partial prolapse of redundant mucosa
- Common in children esp with CF.
Type 2 prolapse?
Full thickness
- Commoner compared to Type 1
- Usually elderly females with poor O+G History
Presentation of rectal prolapse?
- Mass extrudes from rectum on defection
- May reduce spontaneously or require manual reduction
- May become oedematous and ulcerated –> pain and bleeding
- Faecal soiling
- Associated with vaginal prolapse and urinary incontinence
Examination of rectal prolapse?
Visible prolapse: brought out on straining
± excoriation and ulceration
Decreased sphincter tone on PR
Associated with uterovaginal prolapse
Investigations or rectal prolapse?
Sigmoidoscopy to exclude proximal lesions
Anal manometry
Endoanal US
MRI
Management of prolapse?
Partial prolapse
- Phenol injection
- Rubber band ligation
Surgery: delorme’s Procedure
Complete Prolapse
- conservative
PElvic floor exercises
Stool softeners
Surgery of prolapse?
Abdominal approach: rectopexy
- Lap or open
- Mobilise rectum fixed to sacrum with mesh
Perineal approach
- Delorme’s procedure
Resect mucosa and suture the two mucosal boundaries
- Almeirs procedure resects the colon via the perineal route.
Rectal intussceception
Typically presents with with symptoms of obstructed defecation.
Pathology is best demonstrated by defecating proctogram rather than barium enema.
Solitary rectal ulcer?
Associated with chronic straining and constipation
Histology shows mucosal thickening, lamina propria replaced with collagen and smooth muscle.
Diagnostic work up should include endoscopy and probably defacting proctogram.
