Table 2. Kidney stone incidence following bariatric surgery.

Article	Procedure [n]	F/U (mo.)	Post-procedural stone incidence	Comments
Durrani 2006 (25)	RYGB =972	NR	26/85 (31%): recurrent	Stones identified by patient chart review. Mean time to stone formation was 2.8 years (de novo) and 1.9 years (recurrent)
			32/887 (3.6%): de novo
Matlaga 2009 (26)	RYGB [4,639]	18.6	RYGB =355/4,639 (7.7%)	Stones identified by CPT code within claims data versus matched obese controls
	Con [4,639]		Con =215 (4.6%)
Costa-Matos 2009 (27)	RYGB [58]	42†	RYGB =0/58 (0%)	Stones identified by RUS. One patient had a stone pre-RYGB which remained unchanged post-op
Shimizu 2012 (28)	DTGx [226]	NR	31/226 (13.7%)	Stones identified by CT in gastric cancer patients. Incident stones occurred in 25% (21/85) of total vs. 7% (10/141) distal gastrectomy. Mean time to first stone 17.6 months post-surgery
Valezi 2013 (15)	RYGB [151]	12	27/151 (18%): total	A total of 16 patients had pre-existing stones by RUS or by stone history. Post-operative stone formation was predicted by elevated urinary oxalate and uric acid levels
			11/135 (8%): de novo

F/U, follow-up in months, some means are number of months post-procedure; ^†, follow-up time reported as median; RYGB, Roux-en-Y gastric bypass; GB, gastric band; Con, ontrol; CPT, common procedural terminology; RUS, renal ultrasound; BPD, biliopancreatic diversion with duodenal switch; DTGx, distal or total gastrectomy with Bilroth I or Roux-en-Y gastric bypass.