75 year old gentleman recently diagnosed with B-cell lymphoma, staged with CT scan which showed only extensive para-aortic lymphadenopathy and no visceral disease received his first dose of chemotherapy late last week. Six hours later he presented with a perforation involving the greater curvature of the fundus. No mass was palpable, so I mobilized the greater curvature and resected and closed the area of perforation with a TA-90 stapler. Exploration also revealed a friable lesion of the proximal jejunum that appeared on the verge of perforation, so I resected this and placed a gastrostomy and jejunostomy.
Post op course has been stormy. He has run a persistent hyperchloremic metabolic acidosis with compensatory respiratory alkalosis despite good oxygenation and a high urine output (urine osmolality 476, serum osmolality 324, urine Na < 10, serum Na 150). Pathology came back today and reveals lymphoma in the gastric specimen, small bowel specimen and even in some adjacent omentum, which was resected because its viability looked questionable.
1. What is the risk of another perforation with probable residual lymphoma at the resection margin? Would anyone go back and resect more stomach at this point?
2. Why the persistent metabolic acidosis? He does not appear to be septic, (abdomen soft, not tachy, good urine output), but of course that is always a possibility given the recent chemo He did receive Neupogen). He had severe hypercalcemia on presentation (14.5), treated with IV Aredia and saline, but his calcium has subsequently been normal.
3. Does anyone think that the chemo caused the perforation in only 6 hours, or was this lesion headed towards spontaneous perforation before the chemo was given, perhaps explaining the tumor cells in the omentum?