Small bowel and colon transplantation in rats using porto-portal cuff anastomosis.

Portal versus systemic venous drainage and colon grafting are major controversies in the techniques of intestinal transplantation. The rat is the best animal for research in this field. Nevertheless, this model requires complex microvascular anastomoses that are responsible for the high incidence of technical failures. A cuff technique is an easier anastomosis method than a hand-suture. We describe a simplified rat model of small bowel and colon transplantation using a porto-portal cuff anastomosis. DONOR: The entire small bowel, cecum, and ascending colon are harvested on a vascular pedicle, consisting of a long aortomesenteric conduit and portal vein. The right colonic vessels are preserved. The graft is flushed and a cuff device is placed on the end of the portal vein. RECIPIENT: The graft is implanted through an end-to-side aorto-aorta hand-sewn anastomosis. A segment between the first and second jejunal branch is isolated between clamps to insert into the portal cuff. After reperfusion, the recipient's mesentery is divided just below the cuff anastomosis. The recipient jejunum, ileum, and ascending colon are removed en bloc, and the graft is anastomosed in continuity with the remaining naive intestine concluding the operation. This simplified technique surmounts the technical obstacles in rats because it is easily and quickly performed, maintaining the physiological portal drainage, preserving graft ileocecal valve and ascending colon, and reaching acceptable success after a short period of training.

Evaluation of hemodynamic, metabolic, and electrolytic changes after graft reperfusion in a porcine model of intestinal transplantation.

BACKGROUND: We sought to establish an anesthetic protocol to evaluate the hemodynamic, metabolic, and electrolytic changes after graft reperfusion in pigs undergoing orthotopic intestinal transplant (ITx). METHODS: Fifteen pigs were distributed into two groups: GI (n = 6), without immunosuppression, and GII (n = 9), immunosuppressed before surgery with tacrolimus (0.3 mg/kg). The animals were premedicated at 1 hour before surgery with IM acepromazine (0.1 mg/kg), morphine (0.4 mg/kg), ketamine (10 mg/kg), and atropine (0.044 mg/kg IM). Anesthesia induction used equal proportions of diazepam and ketamine (0.1-0.15 mL/kg/IV) and for maintenance in IV infusion of xylazine (1 mg/mL), ketamine (2 mg/mL), and guaiacol glyceryl ether 5% (50 mg/mL), diluted in 250 mL of 5% glucose solution. In addition, recipient pigs were treated with isofluorane inhalation. Heart rate (HR), systolic (SAP), mean (MAP), and diastolic (DAP) arterial pressure, pulse oximetry, respiratory frequency (f), capnography, body temperature (T), blood gas analysis (pH, Paco(2), Pao(2), base excess, BE; Hco(3)(-), Sato(2)), serum potassium (K), calcium (Ca), sodium, hematocrit (Hct), and glucose (Glu) were measured at four times; M0: after incision (basal value); M1: 10 minutes before reperfusion; and M2 and M3: 10 and 20 minutes after graft reperfusion. RESULTS: All groups behaved in a similar pattern. There was significant hypotension after graft reperfusion in GI and GII (M2 = 56.2 +/- 6.4 and M3 = 57.2 +/- 8.3 mm Hg and M2 = 65.7 +/- 10.2 and M3 = 67.8 +/- 16.8 mm Hg, respectively), accompanied by elevated HR. The ETco(2) was elevated at M2 (42 mm Hg) and M3 (40 mm Hg). Metabolic acidosis was observed after reperfusion, with significant increase in K levels. CONCLUSION: The anesthetic protocol for donors and recipients was safe to perform the procedure, allowing control of hemodynamic and metabolic changes after reperfusion without differences regarding immunosuppression.