Surgical management of the right-sided ping (Proceedings)

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Surgical management of the right-sided ping (Proceedings)

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Aug 01, 2011

A large focal right sided ping (>3" diameter) is due to an abnormality of the abomasum or large intestine. Rarely, post-parturient cattle with metritis may have a vague right sided ping in the right caudo-dorsal abdomen due to gas in the uterus. Abnormalities of the forestomach do not cause a right sided ping because the forestomach is on the left of the abdomen. Abnormalities of the small intestine do not cause a large right sided ping because the intestine cannot distend past 3" diameter, even in complete obstruction of the small intestine.

A right displaced abomasum (RDA) is a displacement of the abomasum to the anterior right abdominal quadrant with no vascular occlusion. An abomasal volvulus (AV) is unstable, we then get continued gas and fluid distention and rotation of the proximal duodenum, abomasum, and omasum through a sagittal plane. It is called a volvulus and not a torsion because the axis of rotation primarily involves the mesenteric attachment rather than the longitudinal axis of the organ (the latter indicates a torsion). The AV is categorized as a hemorrhagic strangulating obstruction, since there is vascular occlusion. Occlusion of the duodenum and omasal-abomasal or reticulo-omasal junction leads to abomasal fluid accumulation and metabolic and cardiovascular derangement. The ratio of LDA to AV is approximately 10:1; the ratio of AV to RDA is approximately 3:1

Surgical correction is best performed by a standing right flank approach. Identify whether liver displaced medially by abomasum and major site for twist; RDA - no firm twist palpated, liver is not displaced medially by abomasums; AV - firm twist palpated, liver displaced medially by abomasums. Three different manifestations of AV exist, namely AV, omasal-abomasal volvulus (OAV) and reticulo-omasal-abomasal volvulus (ROAV). These are differentiated on the following basis: AV: a firm twist is located primarily at the omasal-abomasal junction (60% cases); OAV: a firm twist is located primarily at the reticulo-omasal junction (40% cases); ROAV: a firm twist is located primarily at the junction of the rumen and reticulum (rare)

The overall survival rate for AV is approximately 70%. Important preoperative prognostic indicators are heart rate, dehydration, duration of condition, and serum ALP activity. Important prognostic indicators at surgery are AV (90% survive), OAV (55% survive), and ROAV (0% survive). Important postoperative prognostic indicators (first 3 days after surgery) are appetite, presence of diarrhea, absence of abdominal distention, heart rate < 80 bpm. The secrets to improving survival rate are: 1) early diagnosis; 2) surgical technique; 3) perioperative intravenous fluids; and 4) antibiotics for peritonitis

If hypomotility is present after surgery and you are confident that there are no anatomical obstructions or malpositions, then correct acid-base and electrolyte imbalances and administer erythromycin, 10 mg/kg BW, at least once. Hypokalemia and hypochloremia are particularly common and these can be readily corrected with oral KCl (120 g twice a day for a total of 2 doses is a very aggressive rate of administration - this should be the maximum dose). Pre-operative administration of erythromycin increased abomasal emptying rate in the immediate post operative period and increased milk production (and presumably feed intake) in the 3 day period after surgery in cows with abomasal volvulus.

Cecocolic volvulus is dilatation and displacement of the cecum and proximal loop of the ascending colon with severe distension, vascular compromise, and obstruction to digesta flow. The twist is usually located in the proximal loop of the ascending colon because this region is relatively fixed in position, being attached by the greater omentum and common intestinal mesentery dorsal to the descending duodenum. The common mesentery will occasionally be so displaced by the cecocolic volvulus that volvulus of the entire intestinal tract ensues. This is a rapidly fatal condition. Cecal torsion is rotation of the cecum along its longitudinal axis. The colon is not involved in the twist (much rarer than cecocolic volvulus).

Cecocolic volvulus is assumed to result from dilatation and displacement of the cecum and proximal loop of the ascending colon. Cecal torsion results from dilatation and rotation of the cecum at its apical end (distal third of cecum is unattached and free to move). Once a volvulus or torsion has been created, the pathophysiological changes are identical to those observed with hemorrhagic strangulating obstruction elsewhere in the intestinal tract.

Cecocolic volvulus is fatal without surgery. The overall survival rate with surgery is 75-85 % (to normal production levels. Perform a standing right flank laparotomy (which facilitates cecal emptying). Administer flunixin meglumine (1 mg/kg, IV) preoperatively for analgesia.. Gas decompression of the large intestine is normally required; determine location and direction of twist. The blind end of the cecum is gently exteriorized and a typhlotomy performed. Remove up to 20 liters of a green-brown malodorous liquid and close the typhlotomy with a two layer inverting suture pattern. Return the cecum to abdominal cavity and correct the twist, carefully inspect cecum and ascending colon to determine nature and extent of damage. A partial typhlectomy should be performed if the cecum appears necrotic. Administer parenteral antibiotics and intravenous fluid therapy.

Profuse, watery diarrhea should be present within 12 hours of surgical correction of cecocolic volvulus. Failure to pass feces within 24 hours of surgery indicates a second surgery is indicated. A recurrence rate of > 10% has been reported, in which case partial typhlectomy should be performed at the second surgery. Recurrence may reflect a preexisting anatomical abnormality. Partial typhlectomy not recommended at the initial surgery because it prolongs surgical time, increases the degree of abdominal contamination, and is not proven to successfully prevent further episodes of cecocolic volvulus.