MEGACOLON animals & surgery,Treatment .pptx

Veterinary Surgery ,GASTROINTESTINAL SYSTEM�THE LARGE INTESTIN.
LECTURE CONTENTS


MEGACOLON
PROLAPSE OF RECTUM
ANAL SACS IMPACTION (ANAL SACCULECTOMY)
PERIANAL FISTULAS

1. GASTROINTESTINAL SYSTEM THE LARGE INTESTINE Dr.Aman Ullah Zubair [DVM][RVMP]

2. LECTURE CONTENTS MEGACOLON PROLAPSE OF RECTUM ANAL SACS IMPACTION (ANAL SACCULECTOMY) PERIANAL FISTULAS

3. MEGACOLON (1) Usually an end result of chronic mechanical or functional colonic obstruction History of chronic constipation associated with tenesmus , anorexia, vomiting and weight loss Symptoms and Types Constipation; feces trapped in the colon. Obstipation; severe blockage that impedes both feces and gas, keeping them trapped in the colon. Infrequent defecation. Straining to defecate with small or no fecal volume. Small amount of diarrhea may occur after prolonged straining. Hard, dry feces.

4. Hard, Dry feces (a cause of megacolon )

5. MEGACOLON (2) Treatment: Laxatives in the early stages in cases of constipation Surgery in cases that are refractory to medical treatment Colectomy with Coloclonic Ileocolonic or jejunocolonic techniques.

6. PROLAPSE OF ANUS / RECTUM (1) Anal Prolapse (Partial Prolapse): Red, swollen mucosa protruding from anus after defecation. Rectal Prolapse (Complete Prolapse): Protrusion of all layers of rectum through the anal orifice as an enlarged, cylindrical mass. May be fresh or old with necrosis, ulceration, laceration, self mutilation Etiology: Usually secondary to tenesmus from urogenital or ano -rectal disease. Predisposing Causes include gastrointestinal parasitism, typhlitis , colitis, proctitis , tumors of the colon, rectum or anus & dystocia.

7. Anal Prolapse

8. Anal Prolapse

9. Rectal Prolapse

10. PROLAPSE OF ANUS / RECTUM (2) Treatment: A. Manual Reduction with saline and lubricants; 50% dextrose solution to reduce swelling; After reduction, 3-5 purse-string sutures at muco -cutaneous junction with non-absorbable, monofilament material to narrow the anal orifice Place a lubricated syringe or test tube or finger to avoid over tightening Daily cleaning and dressing of the area Remove sutures after 5-6 days In chronic, recurrent cases, perform colopexy .

11. PROLAPSE OF ANUS / RECTUM ( 3 ) B. Rectal Resection and Anastomosis: Place a test tube or a syringe into the rectum to aid in suture placement and to avoid contamination Place four full thickness stay sutures around circumference of the tissue through both layers of the prolapse (outer and inner layer) Resect prolapsed tissue 1-2cm away from the anus Suture the two cut surfaces (outer and inner) with a single layer of simple interrupted, synthetic, absorbable, monofilament material. Sutures are placed full thickness to include submucosa in each bite. Suturing around the circumference can be placed in quadrants ie cut 1/4 th ; suture and then cut the next 1/4 th and suture and so on till completion of the suture line. Reduce the sutured stump and clean the area.

12. Prolapse of Rectum

13. Prolapse of Rectum (Resection)

14. Anal Sacs Impaction (Anal Sacculectomy)-1 Anal Sacs Dogs  have two small pouches on either side of their anus at 4 and 8’O clock position They make a smelly, oily, brown fluid that  dogs use to identify each other and mark their territory It's why they often sniff each other's behinds Anal sac disease begins as an uncomfortable impaction and can progress to an infection or abscess.

15. Position of A nal Sacs

16. Anal Sacculectomy (2) Indications: Chronically infected or impacted anal sacs, anal sac fistulae Surgical Treatment: Closed tech: Insert a small probe, hemostat or balloon tip catheter into the orifice of anal sac duct. Advance the instrument or inflate the balloon with saline to identify the lateral extent of the sac. Make a curvilinear incision over the sac and separate the external and internal anal sphincter muscle fibers from the sac’s exterior with scissors. Dissect out the sac and the duct; place a ligature wd 4/0 suture material around the duct and excise the sac and the duct. Appose s/c tissue and skin with 3/0 or 4/0 material.

17. Closed Sacculectomy

18. Anal Sacculectomy ( 3 ) 2. Open Tech: Place a groove director into the duct of the sac Incise through the skin, s/c tissue, external anal sphincter, duct and sac over the groove director Elevate the cut edge of the sac, dissect it free of its attachments and completely remove the sac wall. Complete the procedure as for closed sacculectomy.

19. Open Sacculectomy

20. PERIANAL FISTULAS (1) Perianal fistula , also known as  anal   furunculosis are tunnel-like formations in the skin and deeper tissues that surround the anal area of dogs A serious condition that most commonly affects German shepherds but may also occur in other purebred or mixed breed  dogs with depressed tail No sex predilection Chronic , progressive condition Single or multiple ulcerated sinuses or fistulous tracts which can involve up to 360 degrees of perianal skin and tissues .

21. Perianal Fistulas

22. Perianal Fistulas

23. Posture dt irritation (perianal fistulas or anal sac infection)

24. PERIANAL FISTULAS (2) Etiology: Still not clear; Broad based tail with low tail carriage, accumulation of fecal material and moisture resulting in inflammation and infection of the skin. Infection from abscessed anal glands, impaction of anal sacs, inflammation and infection of apocrine glands Immune mediated causes

25. PERIANAL FISTULAS ( 2 ) Diagnosis: History, clinical signs and P.E findings; presence of fistulous tracts. Low tail carriage, tenesmus , dyschesia (constipation associated with a defective reflex for defecation) , constant licking of perianal region, severe pain, constipation, rectal and anal bleeding, foul smelling purulent discharge and fecal incontinence. Owners to be told that the disease may be much more severe than is clinically evident. Treatment: Medical: Hygiene of the area with application of antibiotic ointments, corticosteroids and systemic antibiotics (may not be very successful) Immunosuppression with systemic prednisone, cyclosporine

26. PERIANAL FISTULAS ( 3 ) Surgical: Surgical excision of sinuses and fistulous tracts, laser excision, cryosurgery using cryogens (Liquid Nitrogen), chemical debridement and high tail amputation . Goal of surgery is to remove all diseased tissue while preserving as much normal perianal tissue as possible As the anal sacs are often involved, bilateral anal sacculectomy is recommended. During surgical excision / debridement, external anal sphincter should be saved as far as possible, otherwise fecal incontinence will be a problem.