Surgical anatomy (Anorectum Anorectum) Surgery of the anorectum and the perianal region in small animals Dr. T. Németh, DVM, PhD Associate Professor Surgical anatomy (Anorectum Anorectum) Surgical anatomy (Perineum) Zona cutanea Circumanal glands Anal sacs Zona intermedia Zona columnaris Linea anorectalis m. coccygeus m. levator ani m. sphincter ani ext. m. sphincter ani int. m. obturatorius int. a., v. pudenda int. n. pudendus General diagnostic considerations of the anorectal and perianal diseases I. General diagnostic considerations of the anorectal and perianal diseases II. Anamnesis generally chronic history tenesmus in defecation fecal deviation local signs (pruritus, formal deviation ) General signs (alimentary, septicus ) Physical examination inspection palpation superficial rectal (RDP) 1
General diagnostic considerations of the anorectal and perianal diseases III. Suppl. examinations Bloodwork, urinalysis (gen. state) Fine needle aspirate/cytology (tumours tumours) X-ray / pos. contrast rectogr., cystogr. (rectal fistulation, perineal hernia) Rectoscopy (rectal US (perineal hernia CT / MRI rectal tumours) hernia/prostate prostate, perineal tumour/lnn lnn.) General considerations of anorectal and perianal surgery I. Preoperative duties evacuation of rectum (enema) antimicrobial prophylaxis enteral parenteral General considerations of anorectal and perianal surgery II. General considerations of anorectal and perianal surgery III. Surgery atraumatic handling preservation of ext. anal sphincter ani monophil suture materials Postoperative duties Parenteral / enteral feeding / diet analgesia cont. of antibacterial therapy protection of operation site (collar, cleaning) Most important diseases of the region Anal sacculitis Perianalis fistula Anal and rectal tumours Incidence result of diseases with defecation tenesmus of frequent defecation commonly in combination with intussusception 2
assesment of vitality of the prolapsed gut reponability (?) diagnosis of the primary disease (enteritis) Treatment of primary disease 1. reposition purse string suture Treatment of primary disease 1. reposition purse string suture Treatment of primary disease 1. reposition purse string suture Treatment of primary disease 1. reposition purse string suture Treatment of primary disease 1. reposition purse string suture 3
Treatment of primary disease 1. reposition purse string suture Treatment of primary disease 1. reposition purse string suture 2 reposition colopexy ( pull through ) Rectal resection Pull-through Rectal resection Pull-through Rectal resection Pull-through Rectal resection Pull-through 4
Rectal resection Pull-through Incidence mainly in dogs primary or secondary combined with allergodermatitis Local signs Increased amount of content Local irritation abscess / phlegmone / cyst Systemic signs pruritus septic signs allergic reactions conservative surgical Surgery (anal sacculectomy) Conservative therapy precise evacuation of the sac (rectally!!!) parenteral antibiotics analgesia/nsaids closed open 5
Surgery (anal sac removal) Surgery (anal sac removal) Incidence / Aetiology in German shepherd and its mongrels Irish setter, Labrador, Collie uncertain aetiology: immune-mediated mediated (autoimmune autoimmune) Decreased activity of mucosal and circulating IgA hyperaktív local immuniy (IgA, IgG, B-and T-lymphocytes lymphocytes, CD3+, macrophages, plasma cells, IL-2, INF-γ) concurrent chronic colitis Analogy with human Crohn s-disease (?) breed typical chronic, non- healing, recurring analis fistulous tract concurrent colitis breed typical chronic, non- healing, recurring analis fistulous tract concurrent colitis Currently no effective causative treatment!!! 6
conservative (!!!) surgical (!?) Conservative therapy (!!!) Protocol #1 (Michigan State University) diet Prednisolone Azathioprine Protocol #2 (Ontario Veterinary College) diet Cyclosporine Protocol #3 #1 or #2 + Tacrolimus ointment topically Surgery Previous failed techniques cryo-surgery (UK) soft laser tail amputation (USA) castration (???) Current surgical recommendation Anoplasty fistulectomy paraproctectomy cryptectomy (zona columnaris) Anal / Incidence hepatoid circumanal gland tumours (hyperplasia, adenoma, anapl. carcinoma) in male dogs Anal sac tumours (adenocarcinoma) in female dogs rectal adenoma / adenocarcinoma Hepatoid circumanal tumours in male dogs testosterone dependency multilocal perianal lumps (anus anus, base of tail) common ulceration RDP fine needle aspirates / cytology Hepatoid circumanal tumours in male dogs testosterone dependency multilocal perianal lumps (anus, base of tail) common ulceration RDP fine needle aspirates / cytology 7
Hepatoid circumanal tumours in male dogs testosterone dependency multilocal perianal lumps (anus, base of tail) common ulceration RDP fine needle aspirates / cytology Hepatoid circumanal tumours castration (!) (oestrogen inj.) excision of tumour histopath (!) postop. antibiotics local cleansing Hepatoid circumanal tumours castration (!) (oestrogen inj.) excision of tumour histopath (!) postop. antibiotics local cleansing bloody feces tenesmus RDP (pelvic lymphonodes) rectoscopy (US) cytology pull-open excision of tumour (electrocautery) histopath. antibiotics diet 8
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Dorsally positioned intrapelvic localisation: dorsal rectal approach Laterally positioned intrapelvic localisation: lateral rectal approach Caudal intrapelvic localisation: pull pull-through through rectum resection Cranial intrapelvic localisation: ventral rectal approach with pubic osteotomy 10