Distal gastrectomy (DG) is a common operative technique for gastric cancer. Dumping syndrome, reflux esophagitis, and impaired weight gain are encountered in patients undergoing DG. These findings have led to the application of various limited surgical procedures for gastric operations in attempts to improve the patients' quality of life.
Pylorus-preserving gastrectomy (PPG) is a limited surgical procedure that had initially been reported on its efficacy for benign gastric diseases in 1967 by Maki et al. They demonstrated advantages, such as avoidance of the dumping syndrome and protection against mucosal injury of the remnant stomach, as a result of bile regurgitation, which were assumed to be based on the preserved pyloric function. In 1991, Kodama et al first reported the indications of PPG for early gastric cancer on the basis of clinicopathologic analysis. PPG is currently applied as a limited surgical procedure for certain patients with early gastric cancer as a result of the expected benefits obtained by the preservation of the pylorus. However, it has not been well documented that the preserved pylorus works properly without the antrum. The resection of the antrum should have a significant impact on gastric emptying, because antropyloroduodenal coordination is an important factor for an appropriate control of transpyloric flow
( 2,
3,
4,
5 ).
Kazuhiro Nishikawa et al. investigate the functional characteristics of the pylorus in patients undergoing pylorus-preserving gastrectomy (PPG) for early gastric cancer.
In study 1, the overall modified Visick score of postprandial symptoms and the Sigstad dumping score were significantly lower in the PPG group compared with the DG group (P < .05). Early accelerated gastric emptying was observed in both groups for liquids, but only in the DG group for solids. In study 2, isolated pyloric pressure waves induced by intraduodenal lipid infusion and phase III-like activity induced by intravenous erythromycin infusion were preserved after PPG. The quantitative analysis of postoperative symptoms revealed that PPG patients were associated with better clinical conditions than DG patients. The clinical benefits of PPG are considered to be based on the function of the preserved pylorus
( 2 ).
The current clinical results are consistent with previous findings that reported that dumping symptoms were observed in 4% to 46% of DG patients, but only in 0% to 13% of the PPG patients
( 6 ).
As to static symptoms after PPG, Tomita et al reported that all patients at more than 1 year after the operation with group 2 LN dissection had a feeling of gastric fullness after meals and a retention of foods in the residual stomach. Nakane et al reported that postprandial static symptoms, including epigastric fullness, nausea, and vomiting, were observed in 35% of PPG patients without the dissection of suprapyloric LNs, but not in DG patients. In contrast, Imada et al reported that caloric intake was similar between PPG and DG patients long after the operations. In the Nishikawa study, there was no significant difference in the static symptoms including heartburn, chest pain, nausea, regurgitation, upper abdominal pain, and fullness between PPG and DG patients at more than 1 year after the operation
( 7,
6,
8,
2 ).
Laparoscopic-assisted pylorus preserving gastrectomy has also been attempted. Because nodes at the infrapyloric or suprapyloric regions remain unless there is complete dissection ( they belong to the N1 group ), this procedure is indicated when lesions at these two sites are without node metastases
( 1 ).
Horiuchi et al ligated the right gastroepiploic vessels and gastric vessels 1 cm from their origins, whereas Nakane et al preserved the right gastric vessels, vagal nerve, suprapyloric nodes and severed the right gastroepiploic vessels at its origin
( 9,
6 ). There have been no solid data, however , on tumors that do not have nodal metastases at those sites. Without this information, it may not be appropriate to limit nodal dissection from N2, except as part of a clinical study protocol
( 1 ).
For early gastric cancer ( M or SM1 of N0 ) which had unavoidably compelled total gastrectomy, Tomita et al. have so far devised a technique for nearly total gatrectomy with jejunal J pouch interposition as an functional preservation operation by which the vagal nerve, LES, and pyloric sphincter can be preserved. In subjects who underwent conventional total gastrectomy with single jejunal interposition so far, reflux esophagitis, microgastria, or dumping syndrome developed. Therefore since June 1996 the authors have employed nearly total gastrectomy with jejunal J pouch interposition to prevent microgastria, by which the vagal nerve, LES, and pyloric sphincter can be preserved
( 11 ).
Kenichiro Fukuhara et al underline that Billroth I and II reconstructions are commonly performed after distal gastrectomy. Both may cause duodenogastric and duodenogastro-esophageal reflux, conditions reported to have carcinogenetic potential.
Roux-Y reconstruction is superior to either Billroth I or II reconstruction for preventing bile reflux into the gastric remnant and esophagus after distal gastrectomy
( 12 ).
References
1) Y Noguchi et al. Is there a role for nontraditional resection of early gastric cancer? Surg Oncol Clin N Am 11 ( 2002 ) 387-403.
Pub Med
2) Kazuhiro Nishikawa et al. Functional characteristics of the pylorus in patients undergoing pylorus-preserving gastrectomy for early gastric cancer. Surgery 2002;131:613-24.
Pub Med
3) Maki T, Shiratori T, Hatafuku T, Sugawara K. Pylorus-preserving gastrectomy as an improved operation for gastric ulcer. Surgery 1967;61:838-45.
Pub Med
4) Kodama M, Koyama K. Indications for pylorus preserving gastrectomy for early gastric cancer located in the middle third of the stomach. World J Surg 1991;15:628-33.
Pub Med
5) Houghton LA, Read NW, Heddle R, Maddern GJ, Downton J, Toouli J, et al. Motor activity of the gastric antrum, pylorus, and duodenum under fasted conditions and after a liquid meal. Gastroenterology 1988;94:1276-84. Abstract
6) Nakane Y, Akehira K, Inoue K, Iiyama H, Sato M, Masuya Y, et al. Postoperative evaluation of pylorus-preserving gastrectomy for early gastric cancer. Hepatogastroenterology 2000;47:590-5.
Pub Med
7) Tomita R, Takizawa H, Tanjoh K. Physiologic effects of cisapride on gastric emptying after pylorus-preserving gastrectomy for early gastric cancer. World J Surg 1998;22:35-40.
Pub Med
8) Imada T, Rino Y, Takahashi M, Suzuki M, Tanaka J, Shiozawa M, et al. Postoperative functional evaluation of pylorus-preserving gastrectomy for early gastric cancer compared with conventional distal gastrectomy. Surgery 1998;123:165-70.
Pub Med
9) Horiuchi T et al. Laparoscopically assisted pylorus-preserving gastrectomy. Surg Endosc 2001; 15: 235-8.
Pub Med
10) Zhang D, Shimoyama S, Kaminishi M. Feasibility of pylorus-preserving gastrectomy with a wider scope of lymphadenectomy. Arch Surg 1998;133:993-7.
Abstract
11) R Tomita et al. Operative technique on nearly total gastrectomy reconstructed by interposition of a jejunal J pouch with preservation of vagal nerve, lower esophageal sphincter, and pyloric sphincter for early gastric cancer. World J surg. 25, 1524-1531, 2001. Abstract
12) Kenichiro Fukuhara et al. Reconstructive Procedure after Distal Gastrectomy for Gastric Cancer that Best Prevents Duodenogastroesophageal Reflux. World J. Surg. 26, 1452-1457, 2002.
Pub Med
13) Ryouichi Tomita et al. Relationship between Jejunal Interdigestive Migrating Motor Complex and Quality of Life after Total Gastrectomy with Roux-en-Y Reconstruction for Early Gastric Cancer . World J Surg 27, 159-163, 2003.
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