We performed PPPD preserving the right gastroepiploic vessels following PG in two patients. The blood supply of the stomach after PG is maintained in the right gastric and gastroepiploic vessels. When these vessels cannot be preserved, reconstruction of one of these vessels or total resection of the remnant stomach may be necessary in PPPD after PG. Akabane et al.  reported the reconstruction of the right gastroepiploic vessels; however, this is a complicated procedure. Ikeda et al. reported PD after esophageal and gastric surgery preserving the right gastroepiploic vessels . If there is no tumor invasion to the GDA, gastrocolic trunk, or right gastroepiploic vessels, it is possible to preserve the remnant stomach.
Pancreatectomy following gastrectomy should be performed with care regarding the blood supply for the remnant stomach [2, 6]. In the distal pancreatectomy (DP) following distal gastrectomy, the remnant stomach cannot be preserved when the blood supply is insufficient. When the left gastric artery was preserved by performing DG for gastric or duodenal ulcers, the remnant stomach could be preserved safely. Even if the left gastric artery was resected by performing DG for gastric cancer, the remnant stomach may be preserved if the blood supply for the stomach from the inferior diaphragm artery or descending branches of the esophageal artery is confirmed . Takahashi et al.  reported that two of ten patients who underwent distal pancreatectomy after distal gastrectomy developed severe ischemic complications. Because there were some cases in which the remnant stomach could be preserved, intraoperative evaluation of the blood supply is necessary for preserving the remnant stomach.
It is desirable to confirm the blood supply for the remnant stomach, even if one of the gastric vessels can be preserved or reconstructed in PPPD after PG. Recently, several studies have reported intraoperative assessments of blood supply for the digestive tract [7, 8]. Doppler ultrasonography was trialed for the assessment of vascularization of the intestinal edges during colorectal anastomosis . Akabane et al. reported that near-infrared spectroscopy with in vivo optical spectroscopy (INVOS) which allows real-time monitoring of regional saturation of oxygen was useful for confirming the blood supply for intestinal surgery, and it provided an objective and quantitative assessment of intestinal viability . Recently, ICG fluorescence has been used for the assessment of blood flow for the digestive tract, detection of the liver tumor, cholangiography, and sentinel lymph node mapping [10,11,12]. We have shown that ICG fluorescence can be used to assess the viability of the remnant stomach and is potentially useful for evaluating blood flow to the remnant stomach. If the intraoperative objective measurement of the viability of the remnant stomach is established, the remnant stomach can be preserved more safely in patients who undergo pancreatectomy after gastrectomy.
We preserved the right gastroepiploic vessels via GDA and gastrocolic trunk. The right gastric vessels can be preserved technically; however, we considered that it is easier to perform reconstruction, such as pancreatojejunostomy and duodenojejunostomy, and lymph node dissection of the hepatobiliary ligament by preserving the right gastroepiploic vessels. There are some problems with the preservation of GDA, such as the difficulty of this procedure, lymph node dissection, and intraoperative bleeding. Because the tumors were not close to GDA in our cases, we could preserve RGEA via GDA and perform lymph node dissection as usual. We separated RGEA and GDA from the pancreas and resected the anterior superior pancreatoduodenal artery before cutting the drainage veins including posterior superior pancreatoduodenal vein. Therefore, this procedure did not increase the amount of bleeding. When the tumor is close to GDA, like pancreatic cancer with infiltration to the ventral side, preserving GDA may be difficult in terms of the difficulty of technique and lymph node dissection. It is important to preserve the remnant stomach; however, the reconstruction of these vessels is a complicated procedure and it is uncertain to maintain blood flow with reconstruction of the thin blood vessel. Therefore, we planned to perform residual gastrectomy if the RGEA and/or RGEV could not be preserved in our two cases.
In conclusion, the remnant stomach could be preserved in performing PPPD following PG by preserving the right gastroepiploic vessels. PPPD after PG is not a frequent situation, but it is sometimes necessary. ICG fluorescence is one of the useful intraoperative assessments for evaluating blood flow to the remnant stomach.