Anatomy and resection procedures of the stomach. a The four sections of the human stomach. b Schematic drawing of proximal gastrectomy. c Schematic drawing of distal gastrectomy. d Schematic drawing of total gastrectomy
Reconstruction Following Distal Gastrectomy
Methods for Reconstruction
Distal gastrectomy (Fig. 12.1c) includes all procedures that leave the esophago-gastral junction intact, i.e., antrectomy, 2/3 and 4/5 gastric resections. The following reconstructions are most frequently used:
Billroth I, characterized by a gastro-duodenal anastomosis
Billroth II, characterized by a gastro-jejunostomy of the remaining stomach to the first jejunal loop
Roux-en-Y, characterized by a gastro-jejunostomy of the remaining stomach to an excluded jejunal limb and an end to side jejuno-jejunostomy between the excluded jejunum to the first jejunal loop
The reconstruction according to Billroth I (BI) was first performed in 1881 and is characterized by an anastomosis between the remaining stomach and the duodenum (Fig. 12.2a) . Potential advantages of this procedure include the maintenance of a physiological gastro-duodenal passage of the food. Nevertheless, the BI reconstruction is restricted to cases with a limited resection of the distal stomach due to the restricted mobilization possibilities of the duodenum and remaining stomach to establish a tension-free anastomosis. Furthermore, a limited distal resection is contra-indicated in most cases of invasive stomach cancer, thus leaving the BI reconstruction an option mainly after resection of benign lesions, noninvasive tumors, or early malignant lesions. It should be noted, that this type of reconstruction, although commonly not used in Western countries, is an often used mode of reconstruction in Asia.
Reconstruction following distal gastrectomy. a Schematic drawing of Billroth I reconstruction. b Schematic drawing of Billroth II reconstruction. c Schematic drawing of Roux-en-Y reconstruction
The reconstruction according to Billroth II (BII), first performed in 1885, is characterized by a gastro-jejunostomy of the remaining stomach to the first jejunal loop (Fig. 12.2b) . The advantage of this procedure in comparison to BI is the tension-free anastomosis. The main disadvantage is the un-physiological passage of the bilio-pancreatic juice through the stomach due to the missing pylorus. Some patients develop the so-called afferent loop syndrome (ALS), which is caused by an accumulation of bilio-pancreatic juice in the afferent jejunal segment due to a hampered drainage that leads to pain, nausea, and vomiting.
The Roux-en-Y (RY) reconstruction was first described by Woelfler in 1883  and later popularized by C. Roux from 1893 onwards . The Roux-en-Y reconstruction is characterized (after distal resection) by a gastro-jejunostomy of the remaining stomach to a jejunal limb (mostly the second jejunal loop), which has been excluded from the normal intestinal passage (Fig. 12.2c). The procedure involves the blind closure of the proximal duodenum and a second anastomosis between the ascended jejunal limb and the first jejunal loop that carries the bilio-pancreatic juice. The main advantage of the procedure is the reduction of bilio-pancreatic reflux into the stomach due to the distance between the stomach and the jejuno-jejunostomy, which normally has a length of at least 40 cm. The main disadvantage is the exclusion of the duodenal segment from the normal intestinal passage. This exclusion might be the reason for the development of the so-called Roux syndrome in up to 10 % of patients, characterized by a delayed emptying of the stomach into the efferent jejunal loop in the presence of a nonconstricted gastro-jejunal anastomosis.
Summary of Data from Clinical Trials Comparing Reconstructions After Distal Gastrectomy
A meta-analysis concentrating on the comparison of BI vs. RY for reconstruction after distal gastrectomy for stomach cancer combined three RCTs . In addition, this study also performed a meta-analysis on nine observational clinical studies (OCTs). Not all parameters were available in all RCTs. A significant difference in favor of a RY reconstruction compared to BI could be detected for bile reflux (2 RCTs, 71 vs. 75 patients) and remnant gastritis (2 RCTs, 181 vs. 182 patients), while operation time and hospital stay were significantly longer after RY vs. BI (3 RCTs, 240 vs. 238 patients). Of note, reflux esophagitis showed only a tendency, but was not significantly lower after RY (3 RCTs, 227 vs. 231 patients). This trend is substantiated by a significant reduction of reflux esophagitis after RY vs. BI in the meta-analysis of OCTs (5 OCTs, 322 vs. 397 patients). The anastomotic leak rate and anastomotic stricture rate was equally high in both reconstructions (3 RCTs, 240 vs. 238 patients). Taken together, the meta-analysis demonstrated clinical benefits concerning the reduction of bile acid reflux and its consequences for a RY compared to a BI reconstruction.
A second meta-analysis comparing BI or RY including RCTs of distal gastrectomies of both nonmalignant and malignant patient cohorts is available . This meta-analysis did show no significant difference in total postoperative complications or specifically in the anastomotic leak rate in RY vs. BI (4 RCTs, 185 vs. 189 patients). A significant lower rate of reflux symptoms (5 RCTs, 381 vs. 391 patients), reflux esophagitis (6 RCTs, 340 vs. 372 patients), and gastritis (7 RCTs, 337 vs. 377 patients) was found after RY reconstruction vs. BI, while no difference for dumping syndrome was detected (5 RCTs, 361 vs. 391 patients). No significant difference for operation time was evident (3 RCTs, 106 vs. 114), patients after RY vs. BI had a significantly shorter hospital stay (2 RCTs, 91 vs. 91 patients).
The same publication also reported a meta-analysis comparing RY vs. BII reconstructions. No significant differences in total postoperative complications (2 RCTs, 65 vs. 61 patients), while dumping syndrome (2 RCTs, 83 vs. 78 patients), reflux symptoms (2 RCTs, 83 vs. 78 patients), reflux esophagitis (3 RCTs, 60 vs. 68 patients), and gastritis (6 RCTs, 114 vs. 148 patients) were significantly lower in RY vs. BII reconstructed patients.
A third meta-analysis within the same publication compared BI vs. BII reconstructions. While significantly less overall complications (4 RCTs, 738 vs. 280 patients) as well as specifically less anastomotic leaks (3 RCTs, 708 vs. 248 patients) were found in BI vs. BII reconstructed patients, the mortality rate was not significantly different (3 RCTs, 697 vs. 258 patients). Of note, the local recurrence rate was significantly higher after BI vs. BII reconstruction (2 RCTs, 71 vs. 75 patients). Concerning reflux symptoms (2 RCTs, 66 vs. 39 patients), dumping syndrome (2 RCTs, 66 vs. 39 patients), reflux esophagitis (3 RCTs, 68 vs. 67 patients), and gastritis (5 RCTs, 113 vs. 106 patients) no significant differences were found between BI and BII reconstructions.
Evidence Based Recommendations for the Reconstruction After Distal Gastrectomy
As mentioned above, BI reconstruction is only possible in a minority of cases after distal gastrectomy due to the restricted possibilities to mobilize the duodenum and gastric remnant. Two studies comparing BI vs. BII both reported a higher incidence rate of local recurrence after BI, indicating that resection margins and lymph node dissection might have been chosen too limited in order to perform a tension-free anastomosis. As both BI and BII are associated with similar mortality rates as well as symptoms and consequences of bilio-pancreatic reflux, the BI reconstruction is rarely used for malignant diseases in Western countries.
Both the BI and the BII reconstruction have been shown to be inferior in preventing the symptoms and consequences of bilio-pancreatic reflux when compared to RY reconstruction. As the overall survival of patients depends mainly on a radically performed oncological resection, which is in the case of a planned BII or RY not restricted in its dimension, the decision on one of the two reconstruction techniques should be based on the postoperative complication rate and quality of life. As morbidity rates are similar while symptoms resulting from bilio-pancreatic reflux are significantly higher after BII, a RY reconstruction should be favored.
Reconstruction Following Proximal Gastrectomy
Methods for Reconstruction
Proximal resections (Fig. 12.1b) have seen a revival in recent years due to the high number of early gastric cancers in Asian countries that demand a more limited resection than total gastrectomy due to their low frequency of lymph node metastasis . Reconstruction after proximal gastrectomy was initially performed as a direct esophago-gastrostomy, but this procedure comes along with a high rate of gastric reflux . To prevent the occurrence of gastric reflux, different approaches have been tested, including combining a esophago-gastrostomy with a fundoplication , jejunal interposition with and without pouch [19, 20], double tract reconstruction , and ileo-colic interposition . To date, only a few nonrecurrent RCTs have been performed, often reporting on few patients only [18–21]. Of note, two RCTs have been published on the topic of including a pouch or not: both favor a pouch when performing a jejunal interposition [19, 20]. With proximal resections becoming the standard operation for early proximal gastric cancers at least in Asia, more RCTs analyzing different reconstruction methods are expected to be conducted within the next years. Currently, no evidence-based advice can be given upon which procedure to favor.
Reconstruction Following Total Gastrectomy
Methods for Reconstruction
Total gastrectomy (Fig. 12.1d) is performed in all cancer patients where a distal or proximal gastrectomy cannot be performed due to oncological radicalness concerning the distance of resection margins towards the tumor, i.e., in adenocarcinomas greater than T2 of the proximal stomach, hereditary (CDH1 mutated) diffuse gastric cancer or signet ring gastric cancer with an insufficient proximal margin . The following reconstructions are most frequently used:
RY is characterized by an esophago-jejunostomy of the remaining esophagus to an ascended jejunal limb and a jejuno-jejunostomy between the ascended jejunum to the first jejunal loop. The reconstruction can be performed with and without a pouch .
Jejunal or colonic interposition: in the first case characterized by an esophago-jejunostomy and a jejuno-duodenostomy of an interposed jejunal segment. The formation of a pouch can be included in the reconstruction. Similarly, a segment of the colon, i.e., the transverse colon or an ileo-cecal segment can be interposed .
The RY reconstruction after total gastrectomy is similar to the RY after distal gastrectomy and has been described first by Orr in 1947 . The technique is similar to the RY after distal gastrectomy and consists of the formation of an esophago-jejunostomy of the remaining esophagus to a jejunal limb, which has been brought up either via the retrocolic (transmesocolic) or antecolic route (Fig. 12.3a). The length of the jejunal segment that has been brought up and thus excluded from the original small intestinal passage is often longer than in the case of RY reconstruction after distal gastrectomy. The esophago-jejunostomy is commonly performed as an end-to-side anastomosis, resulting in a blind ending of the jejunum (jejunal stump), which should be as short as possible.
Reconstruction following total gastrectomy. a Schematic drawing of Roux-en-Y reconstruction, b Schematic drawing of jejunal interposition, c Schematic drawing of jejunal interposition with pouch
Jejunal and Colonic Interposition
In order to keep the duodenum in the continuity of the intestinal passage the interposition of a jejunal segment after a partial removal of the stomach has already been used by Roux in 1907 . Longmire was the first to apply this technique after total gastrectomy  (Fig. 12.3b). The interposition requires the identification of a long enough jejunal segment (25–30 cm) close to the ligament of Treitz fed by a sufficient jejunal artery. Two anastomoses (a proximal esophago-jejunostomy and a distal jejuno-duodenostomy) re-establish the continuity of the intestinal continuity. Different parts of the colon have also been used to replace the missing stomach [26, 27]. The interposition of a colonic segment is technically more demanding and has not been shown to bring advantages over the jejunal interposition in a randomized trial .
Reconstruction with a Reservoir Formation
In order to re-establish both the intestinal continuity and the physiological function of the stomach to store food, the RY and the jejunal interposition reconstruction have been combined with the formation of a pouch reservoir as a stomach substitute. In addition, also colonic segments have been used for reservoir formations. Multiple different approaches have been described in the literature for the formation of a reservoir, several of them evaluated in RCTs .< div class='tao-gold-member'>