The herniated organs are replaced into the pelvic cavity by gentle manipulation and then a clear view of the funnel is obtained. On the medial side is the rectum, terminating at the anal sphincter. This usually is the only structure on the medial side into which sutures can be inserted. The muscular structures on the lateral side of the funnel are not easily seen but may be identified by palpation. The levator ani and coccygeus muscle are on the dorsolateral surface of the funnel, Stainless steel wire, nylon or catgut sutures are inserted through these muscles and into the dorsal part of the anal sphincter. Some surgeons feel chromic gut is best because it provokes a fibrous tissue reaction that contributes to the strength of repair, however, the author prefers stainless steel wire (26 gauge). The internal obturator muscle is also sutured to the ventrolateral aspect of the rectum,
Immediately below these sutures, additional ones are inserted between the anal sphincter and sacrotuberous ligament. This ligament is a fairly broad band that can be identified by passing the finger along the medial wall of the pelvis and hooking the finger backward. The ligament may be mistaken for bone. The lower portion of the opening is closed by inserting a series of sutures through the internal obturator muscle which lies on the floor of the pelvis, and the ventral surface of the anal sphincter. This is difficult because the structures lie deeply within the pelvis and careful manipulation is necessary.
When inserting the lower sutures between the head of the internal obturator muscle and ventral portion of the anal sphincter, care must be taken to avoid injuring the blood and nerve supply to the anus, The muscles of the anal sphincter are supplied by anal branches of the pudendal nerve and by the perineal arteries and satellite veins, These structures will be encountered in a band along the ventral aspect of the rectum. Injury to the nerve might result in fecal incontinence.The sutures should not be tied until all have been inserted,' otherwise increasing difficulty will be encountered in placing the sutures. Following closure of the initial suture line an attempt is made to locate intact perineal fascia that may have retracted laterally. The edge of the fascia is grasped with an Allis forceps and a flap is formed by dissecting the outer surface of the fascia away from the overlying skin, The fascia flap is pulled medially and sutured to the most caudal portion of the anal sphincter Another series of sutures is inserted in the subcutaneous tissues and excessive skin is trimmed to assure adequate and accurate closure.
Possible complications following repair of a perineal hernia include fecal and urinary incontinence, wound infection from fecal contamination and lameness resulting from damage to the sciatic nerve during surgery. In severe cases, nylon mesh may be used to form a "diaphragm" that prevents the caudal displacement of the viscera,
Post-Operative Care and Prognosis
Routine prophylactic chemotherapy is advisable and a low residue diet should be fed to prevent excessive straining during defecation, In most cases recurrence is not a problem. Both sides of a bilateral hernia should not be operated at the same time since this would put too much stress on the external anal sphincter. A 4 to 6 week lag should occur between surgeries, unless a newer obturator lift method is employed.
Obturator Lift for Simultaneous Bilateral Perineal Hernia Repair
The approach to this surgery is identical to traditional repair, and after exposure herniated organs are retropulsed back into the abdomen. Identification of the external anal sphincter, sacrotuberous ligament and the internal obturator is severed at the point that it passes laterally over the body of the ischiurn, The muscle is then brought dorsally to fill the defect left by the hernia, Initial suture is placed between the lateral aspect of the external anal sphincter and the sacrotuberous ligament and gluteal fascia as far dorsal as possible in order to create a bed for the apex of the internal obturator is sutured to the caudomedial edge of the sacrotuberous ligament with 4 - 6 (1.0) nylon cruciate pattern sutures. The caudomedial border of the internal obturator is likewise sutured to the external anal sphincter. Replacement of all sutures before knot's are thrown facilitates the task. Layered subcutaneous closure is accomplished with gut to obturate dead space Skin closure is routine.
Congenital Abnormalities- Peritoneopericardial Hernia
This condition is referred to as congenital diaphragmatic hernia. It is a relatively common condition in which the septum transversum fails to develop properly resulting in incomplete separation of the peritoneal and pericardial cavities. This condition has been seen in many breeds from birth to 15 years of age, but most commonly in animals under 2 years.
Clinical Signs - Peritoneopericardial Hernia
Vomiting, anorexia, lethargy and diarrhea are common signs whereas dyspnea is an infrequent sign. Ventral abdominal hernias have also been present in affected dogs. This condition often goes undetected until radiographs are taken for reasons such as heart disease, gastroenteritis, pneumonia or neoplasia.