Applications on proximal gastrectomy with gastroesophageal muscular flap anastomosis in laparoscopic surgery: a narrative review

Abstract

In recent years, the detection rate of early upper gastric cancer has increased substantially, leading to improved overall patient prognosis and elevating postoperative quality of life to a key clinical priority. Consequently, function-preserving proximal gastrectomy has emerged as a promising surgical strategy. With the widespread adoption of minimally invasive techniques, laparoscopic proximal gastrectomy has become the standard approach; furthermore, the integration of robotic-assisted surgery has further refined the precision and feasibility of minimally invasive proximal gastrectomy. However, proximal gastrectomy frequently compromises the anatomical and functional integrity of the cardia and its surrounding structures, predisposing patients to postoperative gastroesophageal reflux—a major source of morbidity. To mitigate this complication, numerous digestive tract reconstruction methods have been proposed; yet, no consensus exists regarding the optimal technique. Accordingly, the development of an effective, evidence-based reconstruction method to minimize postoperative reflux remains the central challenge in proximal gastrectomy. Gastroesophageal muscular flap anastomosis is one such reconstructive approach designed to reduce reflux while preserving nutritional absorption. By creating a valve-like “artificial cardia” that permits unimpeded food passage, gastroesophageal muscular flap anastomosis aims to restore anti-reflux competence without compromising gastric emptying or intestinal transit. It is currently recommended as a preferred reconstruction strategy in laparoscopic proximal gastrectomy. The principal clinical questions surrounding gastroesophageal muscular flap anastomosis pertain to its efficacy and safety in preventing reflux, as well as its long-term impact on nutritional status and health-related quality of life. Current evidence suggests that gastroesophageal muscular flap anastomosis can significantly alleviate reflux-related symptoms and help maintain body weight and key nutritional parameters, with encouraging short-term outcomes reported across multiple studies. Nevertheless, existing clinical data are limited by methodological heterogeneity—including variations in surgical technique, definition of reflux endpoints, outcome assessment tools, and follow-up duration—thereby constraining the generalizability of current conclusions. Rigorous, multicenter, prospective randomized controlled trials with standardized protocols and long-term follow-up are warranted to validate the role of gastroesophageal muscular flap anastomosis in proximal gastrectomy.

Introduction

The incidence of upper gastric cancer has increased in recent years, garnering significant attention from the surgical community [1–3]. Historically, total gastrectomy has been the standard treatment for upper gastric cancer. However, advancements in medical practices and the increased early detection of gastric cancer have led to a common surgical goal of preserving gastric function as much as possible while ensuring complete tumour resection. According to guidelines established by both the Chinese Clinical Oncology Society and the Japanese Gastric Cancer Association, proximal gastrectomy may be performed for early-stage gastric cancer when more than half of the distal stomach is preserved [4, 5]. Proximal gastrectomy is primarily indicated for early-stage cT1–2N0 gastric cancer located in the upper stomach or at the gastroesophageal junction, with a tumor diameter generally recommended to be less than 4 cm. The procedure should ensure that at least 50% of the distal stomach can be safely preserved. In patients who strictly meet these criteria, the 5-year overall survival and disease-free survival rates are comparable to those achieved with total gastrectomy, offering radical oncologic treatment while better preserving gastric function. Evidence suggests that patients who undergo proximal gastrectomy for early-stage disease experience no adverse effects on long-term survival and can benefit significantly from improved postoperative nutritional status [6]. The etiology of gastroesophageal reflux disease primarily involves the abnormal reflux of gastric contents into the esophagus, resulting in mucosal damage and associated symptoms. The principal causes include dysfunction of the lower esophageal sphincter, impaired esophageal clearance, hiatal hernia, and delayed gastric emptying. In individuals without this condition, normal functioning of the anti-reflux mechanisms at the esophagogastric junction-such as a properly functioning lower esophageal sphincter-prevents esophagogastric reflux. However, proximal gastrectomy compromises structures such as the cardia and its surrounding tissues, including the lower oesophageal sphincter, angle of His, and cardiac sphincter, which serve critical anti-reflux functions. As such, the incidence of gastroesophageal reflux following proximal gastrectomy is increased. Moreover, postoperative damage to the vagus nerve can lead to reduced functioning of the residual stomach, resulting in delayed gastric emptying and exacerbating gastroesophageal reflux, which can lead to esophageal stricture and dysphagia symptoms. Dysphagia significantly impacts the postoperative quality of life of patients [7–10]. Consequently, strategies aimed at reconstructing the gastroesophageal tract while minimizing postoperative reflux have become a focal point in gastroesophageal reconstruction following proximal gastrectomy. There are various approaches to reconstructing the digestive tract following proximal gastrectomy, each with its own advantages and disadvantages. Currently, no universally accepted standard method exists for digestive tract reconstruction. In recent years, gastroesophageal muscular flap anastomosis has garnered significant attention for its favourable anti-reflux properties, establishing gastroesophageal muscular flap anastomosis as a prominent area of research. The muscular flap anastomosis generally includes double muscular flap anastomosis and single muscular flap anastomosis. The aim of this review was to investigate the anti-reflux effect and clinical applications of gastroesophageal muscular flap anastomosis based on existing research, providing valuable insights for digestive tract reconstruction in laparoscopic proximal gastrectomy. This study constitutes a narrative expert review and, therefore, does not employ a formal review methodology.

Techniques for gastroesophageal reconstruction after proximal gastrectomy

In proximal gastrectomy, the requirements for gastroesophageal reconstruction are as follows: (1) the procedure should be convenient and safe; (2) the residual stomach must possess a sufficient volume to accommodate food; (3) anti-reflux efficacy is essential; (4) ensuring the physiological passage of food through the duodenum while maintaining its digestive and absorptive functions, along with those of the proximal jejunum, is crucial; and (5) postoperative convenience for endoscopic examination should be facilitated. Gastroesophageal reconstruction in proximal gastrectomy is primarily categorised into two types: gastroesophageal anastomosis, which features a relatively simple anastomotic site and straightforward surgical technique, and gastroesophageal jejunal anastomosis, which uses interposed jejunum and double-channel anastomosis techniques.

After proximal gastrectomy, various methods for gastroesophageal reconstruction have been proposed by different researchers (Table 1). Oesophagogastrectomy is primarily performed with an interposed segment of the jejunum that provides a buffer against reflux. The double-tract anastomosis technique was first reported by Japanese researcher Aikou et al. [11] in 1988 and is particularly suitable for most proximal gastric resections aimed at gastroesophageal reconstruction. Compared with traditional anastomosis between the esophagus and stomach, double-tract anastomosis has a lower incidence of both anastomotic stricture and reflux oesophagitis [12]. However, this approach is more complex and involves multiple anastomotic sites, increasing the risk of postoperative anastomotic fistulae. Additionally, the use of more linear staplers may increase overall costs. In 1993, Kameyama et al. [13] first proposed employing an interposed jejunum segment, serving as a barrier against reflux, for gastroesophageal reconstruction following proximal gastric resection. Nonetheless, this surgical technique presents complexities that may lead to postoperative dysphagia, malnutrition and dumping syndrome [14, 15].

Table 1.

Techniques for gastroesophageal reconstruction after proximal gastrectomy

Ref.	Year	Gastroesophageal reconstruction	Sample size	Operation time (min)	Postoperative hospital stay (d)	Postoperative complication rate	Anastomotic complication rate	Proportion of reflux	Nutritional status
Aikou et al. [11]	1988	Double-tract anastomosis	Not applicable	Not applicable	Not applicable	Not applicable	Not applicable	Not applicable	Not applicable
Kameyama et al. [13]	1993	Jejunal pouch interposition anastomosis	Not applicable	Not applicable	Not applicable	Not applicable	Not applicable	Not applicable	Not applicable
Shiraishi et al. [16]	1998	Gastric tube anastomosis	1	Not applicable	Not applicable	0%	0%	0%	Not applicable
Yamashita et al. [17]	2017	Side overlap anastomosis	14	273–361	8–20	0%	0%	7.10%	The mean weight experienced a reduction of 7.4%
Kuroda et al. [18]	2016	Double-flap anastomosis	33	188–408	Not applicable	12.10%	9.10%	0%	Not applicable

Traditional gastroesophageal anastomosis is relatively straightforward to perform; however, it is associated with a high incidence of severe postoperative reflux, which has led to its gradual abandonment. Shiraishi et al. [16] introduced a tube-shaped gastric gastroesophageal anastomosis in 1998, which facilitated the rapid passage of food postoperatively that prevented stasis and demonstrated excellent anti-reflux properties. Nevertheless, the excessively long cut edges of the tubular stomach, along with its straight configuration and reduced capacity, increases the risks related to injury to the tubular gastric arteries and veins during surgery as well as postoperative complications such as bleeding, gastric fistula, and anastomotic fistula [19]. Yamashita et al. [17] developed a laparoscopic proximal gastrectomy technique using gastroesophageal sidewall anastomosis, known as side-overlap anastomosis, which has been shown to effectively reduce postoperative reflux. This technique is characterised by its simplicity and relatively short operative time while also providing a wider anastomotic site that may decrease the incidence of postoperative anastomotic stenosis. However, side-overlap anastomosis necessitates the preservation of a longer segment of the distal esophagus and a larger residual stomach, thereby limiting its applicability. In contrast, Kamikawa et al. [18] introduced Kamikawa anastomosis, which employs a double muscular flap technique for connecting the esophagus and stomach. This method is particularly suitable for patients with upper gastric cancer who are estimated to have more than 50% residual stomach volume postoperatively. Kamikawa anastomosis has emerged as a prominent area of research in the field of digestive tract reconstruction following proximal gastrectomy owing to its remarkable anti-reflux properties. Unlike other gastroesophageal reconstruction techniques, Kamikawa anastomosis reconstructs the anastomotic site by creating double muscular flaps that encircle and support the gastroesophageal junction in a manner akin to reconstructing the cardia, functioning as a one-way valve. The use of double muscular flaps serves to cover and reinforce the anastomotic area, thereby reducing the risk of postoperative anastomotic fistula without compromising subsequent endoscopic evaluations. However, the choice of reconstruction is largely influenced by residual gastric volume. In particular, double-tract reconstruction can be applied even when the remnant stomach is relatively small, whereas Kamikawa anastomosis is generally difficult to perform in such cases.

Application of the double muscular flap technique

The surgical focus of the Kamikawa anastomosis technique is to create double muscular flaps. Initially, an “H”-shaped (3.0 cm × 3.5 cm) muscular flap is created on the anterior wall of the residual stomach adjacent to the greater curvature. The mucosal and submucosal layers are incised beneath the muscular flap, after which the oesophageal stump is opened and sutured to the mucosal window of the residual stomach for closure. Ultimately, the oesophagogastric anastomosis is enveloped by these double muscular flaps. Similar to gastric fundoplication, the transmission of increased intragastric pressure to the tightly adhered posterior wall of the esophagus facilitates its closure, thereby achieving anti-reflux efficacy [20–23]. Concurrently, reconstruction of an artificial gastric fundus forms an artificial angle of His, contributing to a robust anti-reflux barrier. Given that only one anastomosis is established following gastroesophageal reconstruction and that this anastomosis is covered by a muscular flap, the risk of postoperative anastomotic fistulae is significantly reduced.

Since Kamikawa introduced the double muscular flap anastomosis technique, numerous researchers have implemented it in laparoscopic proximal gastrectomy (Table 2). The Kamikawa anastomosis technique has favourable anti-reflux efficacy and is associated with a reduced likelihood of postoperative anastomotic fistula formation [24–29]. The Kamikawa anastomosis technique facilitates anastomosis through manual suturing, offering a cost-effective approach. However, this complex procedure requires a high-level of operative skill, particularly in laparoscopic suturing techniques. Consequently, the duration of the operation tends to be longer. In contrast, robotic surgical systems offer enhanced visualisation and provide more flexible and stable manipulation during procedures, thereby benefiting laparoscopic operations by reducing both the degree of technical difficulty and the overall operation time [30, 31]. A critical aspect of the double muscular flap anastomosis technique is the creation of the muscular flap. If this flap is excessively short or if the anastomosis is sutured too tightly, resulting in excessive tension, there is a risk of stenosis at the anastomotic site. Additionally, any injury to either the gastric mucosa or the muscular flap during surgery may lead to complications such as anastomotic fistula formation. Furthermore, an inadequate blood supply to the muscular flap can compromise its postoperative anti-reflux efficacy. The Kamikawa anastomosis technique necessitates the use of a double muscular flap, which in turn requires the preservation of a larger stomach. These factors contribute to the limited popularity of this surgical approach.

Table 2.

Application of the double muscular flap technique

Ref.	Year	Gastroesophageal reconstruction	Sample size	Operation time (min)	Postoperative hospital stay (d)	Postoperative complication rate	Anastomotic complication rate	Proportion of reflux	Nutritional status
Kuroda et al. [18]	2016	Laparoscopic double muscular flap anastomosis	33	188–408	Not applicable	12.10%	9.10%	0%	Not applicable
Kuroda et al. [25]	2019	Laparoscopic double muscular flap anastomosis	464	247.5-370.5	13-20	Not applicable	7.20%	10.60%	Not applicable
Muraoka et al. [26]	2016	Laparoscopic double muscular flap anastomosis	24	279–480	Not applicable	37.50%	33.30%	12.50%	Not applicable
Shoji et al. [27]	2019	Laparoscopic double muscular flap anastomosis	147	244–641	7–45	12.20%	2.70%	4.20%	Not applicable
Shibasaki et al. [30]	2017	Robotic double muscular flap anastomosis	12	324–613	9–30	33%	25%	16.70%	The mean weight experienced a reduction of 10%
Mine et al. [32]	2016	Intrathoracic double muscular flap anastomosis	4	Not applicable	Not applicable	0%	0%	0%	Not applicable

Traditional proximal gastric resection with gastroesophageal reconstruction is typically performed intra-abdominally. However, for certain tumours located higher in the gastroesophageal junction, it may be necessary to conduct gastroesophageal reconstruction in the retroperitoneum or even within the thoracic cavity. When a gastroesophageal anastomosis is executed, a tubular stomach is generally created to facilitate improved gastroesophageal reconstruction. Existing literature suggests that the creation of a tubular stomach for Kamikawa anastomosis within the thoracic cavity can be performed safely and effectively through thoracoscopic surgery. This approach yields favourable short-term outcomes, with no evidence of gastroesophageal reflux or anastomosis-related complications [32–35]. Nevertheless, some authors contend that performing gastroesophageal reconstruction within the thoracic cavity may increase the risk of postoperative reflux oesophagitis because of the negative pressure conditions present in that area [18].

Male patients who undergo mediastinal or thoracic anastomosis with an oesophageal diameter of less than 18 mm at the level of diaphragmatic insertion are identified as having an independent risk factor for developing an anastomotic stricture following proximal gastrectomy with Kamikawa anastomosis [27]. The incidence of postsurgical anastomotic stricture increases in correlation with the number of interrupted sutures and stitches [36]. Consequently, for male patients requiring anastomosis within the mediastinal or thoracic cavity, oesophagojejunal anastomosis is recommended as a method for digestive tract reconstruction. To mitigate the risk of postoperative anastomotic stricture, patients presenting with oesophageal diameters equal to or greater than 18 mm at the level of diaphragmatic insertion are advised to undergo Kamikawa anastomosis. Surgical teams lacking proficiency in laparoscopic techniques may consider preparing muscular flaps or conducting digestive tract reconstruction externally. Furthermore, surgeons should aim to minimise the use of interrupted sutures by opting for continuous suturing techniques and reducing the total number of stitches used during the procedure.

Modifications of Kamikawa anastomosis

In response to the limitations of traditional Kamikawa anastomosis, Zong et al. [37] implemented several modifications (Fig. 1): (1) Total mesoesophageal excision was performed at the gastroesophageal junction. (2) The width of the anastomosis was matched to the diameter of the esophagus to reduce the incidence of postoperative anastomotic stenosis. (3) An ultrasonic scalpel was used to cut the oesophageal end, which helps prevent retraction and bleeding of the oesophageal mucosa, thereby avoiding the need for intermittent, multiple sutures in this area. (4) Barbed sutures were employed to secure both the esophagus and the base of the residual stomach, thus minimising operational difficulties within a confined space. (5) Additionally, barbed sutures were used for both anastomosis closure and muscular flap coverage, effectively shortening the surgical time. The Kamikawa anastomosis technique effectively prevents reflux while optimising the surgical process, thereby shortening operative time and minimising the use of disposable materials. Omori et al. [38] introduced the innovative Tri-Doubleflap anastomosis technique, which involves the creation of two muscular flaps and employs a linear stapler to seal both the oesophageal and gastric mucosal windows while closing the common opening (Fig. 2). This method ultimately covers the anastomosis with double flaps. Compared with the traditional Kamikawa anastomosis technique, the Tri-Doubleflap anastomosis technique results in a shorter operative time and a lower incidence of postoperative reflux and other complications.

Fig. 1.

The modified Kamikawa anastomosis technique aligns the width of the anastomosis with the diameter of the esophagus and employs barbed sutures for the suturing process

Fig. 2.

The Tri-Doubleflap anastomosis technique involves the creation of two muscular flaps and employs a linear stapler to seal both the oesophageal and gastric mucosal windows while closing the common opening

Nutritional status following Kamikawa anastomosis

Kamikawa anastomosis preserves the normal anatomical structure and functions of the digestive tract, including storage, absorption, and secretion. This technique helps reduce the risk of anaemia and weight loss in patients after surgery, thereby ensuring a better nutritional state. Research suggests that, in comparison with laparoscopic total gastrectomy, patients who undergo laparoscopic proximal gastrectomy with Kamikawa anastomosis have an increased body mass index (BMI) and nutritional parameters [39, 40]. The findings of Kano et al. [41] demonstrated that haemoglobin levels were significantly higher in patients who underwent laparoscopic proximal gastrectomy with Kamikawa anastomosis compared with those who received laparoscopic subtotal gastrectomy during the second and third years following surgery. Additionally, the retrospective study by Kumamoto et al. [42] revealed that the incidence of reflux oesophagitis and anastomotic complications after Kamikawa anastomosis is comparable to that observed with interposed jejunal anastomosis. However, patient outcomes regarding body mass and albumin levels are more favourable following Kamikawa anastomosis. Furthermore, research conducted in Japan suggests that laparoscopic proximal gastrectomy combined with Kamikawa anastomosis effectively prevents skeletal muscle loss in postoperative patients [43]. Overall, this surgical approach not only enhances nutritional status but also improves quality of life for patients (Table 3).

Table 3.

Nutritional status following Kamikawa anastomosis

Ref.	Year	Gastroesophageal reconstruction	Nutritional status
Tsumura et al. [39]	2020	Laparoscopic double muscular flap anastomosis	The median weight experienced a reduction of 15.1%
Hayami et al. [40]	2017	Laparoscopic double muscular flap anastomosis	The mean weight experienced a reduction of 12%
Kano et al. [41]	2019	Laparoscopic double muscular flap anastomosis	The median Hb concentration was 13.1 g/dl
Kumamoto et al. [42]	2021	Laparoscopic double muscular flap anastomosis	The mean weight experienced a reduction of 8.1%
Ri et al. [43]	2021	Laparoscopic double muscular flap anastomosis	The median SMI experienced a reduction of 6.3%

Hb haemoglobin, SMI skeletal muscle index

Application of single muscular flap anastomosis

On the basis of the Kamikawa anastomosis, some researchers have proposed the single muscular flap anastomosis technique. In contrast to the “collar”-like structure formed by Kamikawa anastomosis, single muscular flap anastomosis can achieve a comparable “tunnel”-like effect in covering the site of anastomosis. Furthermore, compared with Kamikawa anastomosis, single muscular flap anastomosis presents a reduced risk of stenosis following suturing and burial.

Peng et al. [44] modified the Kamikawa anastomosis technique in 2021, introducing the right-opened single muscular flap shaping technique (Fig. 3). Unlike traditional Kamikawa anastomosis, which involves the creation of two separate muscular flaps, this innovative approach involves the construction of a single “匚”-shaped muscular flap on the anterior wall of the residual stomach. This is achieved via the use of a linear stapler to seal both the anterior mucosal wall of the stomach and the posterior wall of the esophagus. Subsequently, barbed sutures are employed to close the common opening, with final coverage provided by the single muscular flap. Compared with the Kamikawa anastomosis technique, this single muscular flap shaping method requires fewer sutures, results in a shorter operative time, and reduces procedural complexity. The anti-reflux mechanism inherent in this right-opening single muscular flap shaping technique is similar to that of double muscular flap anastomosis. It positions the esophagus flat against the anterior wall of the residual stomach and is sutured in place, resembling a side-overlap anastomosis at the gastroesophageal junction. When the muscular flap is constructed on the anterior wall of the residual stomach, the right-opening single muscular flap shaping technique involves making a longitudinal incision in the seromuscular layer of the anterior wall on the left side. This approach is designed to better preserve blood vessels that originate from the greater curvature of the stomach, thereby ensuring an adequate blood supply and preventing ischaemic necrosis of the muscular flap. According to previous studies, this technique demonstrates significant efficacy in preventing postoperative reflux and complications associated with anastomosis. However, for tumours located in the high oesophagogastric junction, the applicability of this technique remains uncertain.

Fig. 3.

The right-opening single muscular flap technique involves the construction of a single “匚”-shaped muscular flap on the anterior wall of the residual stomach, which is designed to cover the anastomosis

Li et al. [45] modified the gastroesophageal “arch bridge” anastomosis, which resembles the right-opened single muscular flap procedure, by developing a “匚”-shaped single muscular flap on the anterior wall of the residual stomach (Fig. 4). The specific surgical steps are as follows: A “匚”-shaped single flap (3.0 cm × 4.0 cm, width × height) was created extracorporeally by dissecting the submucosal and muscular layers of the anterior gastric remnant wall, 2 cm from the incisal edge; the flap opened toward the lesser curvature. Its edges were interruptedly sutured with 4 − 0 absorbable suture to form an “arch-bridge”. An orifice (2 cm in diameter) was then created on the anterior gastric remnant wall, 1 cm below the arch-bridge, and its margin was secured with four interrupted 4 − 0 absorbable sutures. The esophagus was pulled through the arch-bridge using two pre-placed V-Locs. The distal esophageal stump was transected with an ultrasonic dissector. The posterior esophageal stump wall was then continuously sutured to the proximal margin of the gastric orifice using one barbed suture; the anterior esophageal stump wall, the distal orifice margin, and the caudal edge of the arch-bridge were continuously sutured together with a second barbed suture. Esophagogastric reconstruction was thus completed, with the anastomosis fully covered by the single “arch-bridge” flap. This modified gastroesophageal “arch bridge” anastomosis not only preserves the muscular ability to augment pressure in the lower esophagus to prevent reflux but also reduces operational complexity.

Fig. 4.

The “arch bridge” single muscular flap technique involves the development of a “匚”-shaped single muscular flap on the anterior wall of the residual stomach, which creates a “bridge” that effectively covers the anastomosis

In 2022, Wang et al. [46] introduced laparoscopic proximal gastric resection utilising a single muscular flap technique (Fig. 5). In this surgical approach, a small incision is made below the esophagus to insert a staple holder, followed by a counterpuncture from this incision at the upper right side to extract it through that route. This surgical approach is akin to that of the right-opened single muscular flap procedure. Wang et al. fashioned a “コ” shaped single muscular flap on the anterior wall of the residual stomach and inserted a circular anastomosis device into it. They subsequently punctured beneath this “コ”-shaped muscular flap and extracted the anastomosis device through it, successfully completing end‒end anastomosis with the lateral wall of the esophagus under laparoscopic guidance. All patients exhibited no stenosis or reflux postoperatively, demonstrating favourable short-term outcomes. Single muscular flap anastomosis was superior to traditional Kamikawa anastomosis in terms of reducing procedural difficulty while maintaining good postoperative anti-reflux effects.

Fig. 5.

The “コ” shaped single muscular flap technique involves the creation of a “コ” shaped single muscular flap on the anterior wall of the residual stomach. A: Make an incision approximately 1 cm to 2 cm below the esophagus, and insert the 25 mm stapler anvil along with a needle; B: Perform a reverse puncture to extract the staple anvil from the esophagus; C: 3 cm proximal to the anterior wall of the remnant stomach, a “コ” shape was delineated using methylene blue. The serosa and muscularis of the upper and lower horizontal sides, as well as the right vertical side of the “コ” shape, were incised with an electrosurgical knife. In contrast, the left serosa was preserved to create a single muscular flap; D: A circular anastomosis device is subsequently inserted beneath this flap, facilitating end-to-end anastomosis with the lateral wall of the esophagus

Peng et al. [47] modified the gastroesophageal “tunnel” anastomosis technique (Fig. 6). They delineated and constructed a rectangular muscular flap tunnel measuring 3.0 cm × 3.5 cm on the anterior wall of the remnant stomach, which was situated near the greater curvature. The anterior and posterior walls of the upper edge of this flap were secured to approximately 5 cm above the upper margin of the oesophageal stump. The oesophageal stump was subsequently positioned within this tunnel and manually sutured to the remnant stomach. The advantages of this method include the following: (1) The blood supply of the muscular flap is preserved, as it does not need to be dissected. Moreover, this approach enlarges the anastomotic opening, which may contribute to a reduction in the incidence of anastomotic stenosis postoperatively. (2) The procedure is relatively straightforward, thereby reducing surgical complexity. Research findings indicate that this operation is safe and has a definitive anti-reflux effect. However, it should be noted that this technique relies entirely on hand suturing; thus, performing a complete laparoscopic suture operation poses significant challenges and necessitates extra-abdominal assistance.

Fig. 6.

The “tunnel” anastomosis technique involves the creation of a rectangular muscular flap tunnel on the anterior wall of the remnant stomach, which is situated near the greater curvature. The oesophageal stump is subsequently positioned within this tunnel and manually sutured to the remnant stomach

Various single muscular flap techniques are modifications derived from the double muscular flap technique. Their underlying anti-reflux mechanisms are fundamentally similar. Anastomotic stenosis or failure primarily results from either a mismatch in anastomotic diameter between the esophagus and stomach or ischemia of the musculare flap. These factors warrant careful attention in clinical practice. The advantages and disadvantages of the different gastroesophageal muscular flap anastomoses in laparoscopic proximal gastrectomy discussed in this review are summarized in Table 4.

Table 4.

Advantages and disadvantages of the different gastroesophageal muscular flap anastomosis

Methods of digestive tract reconstruction	Advantages	Disadvantages	Operation time (min)	Postoperative hospital stay (d)	Postoperative complication rate	Anastomotic complication rate	Proportion of reflux	Nutritional status
Traditional Kamikawa anastomosis [18]	This technique has favourable antireflux efficacy and is associated with a reduced likelihood of postoperative anastomotic fistula	This technique is intricate to execute, and if the flap is not adequately prepared, it may lead to stenosis of the anastomosis post-surgery.	188–408	Not applicable	12.10%	9.10%	0%	Not applicable
Modified Kamikawa anastomosis [37]	This technique effectively ensures anti-reflux while optimizing the surgical process, thereby shortening the duration of surgery and minimizing the consumption of disposable materials.	This technique still necessitates specific laparoscopic operational skills and presents certain challenges.	348 ± 108	13.8 ± 2.9	16%	12%	4%	Not applicable
Tri-Doubleflap anastomosis [38]	Compared to traditional Kamikawa anastomosis, this technique demonstrates a reduced operation time and a lower incidence of postoperative reflux as well as other complications.	This technique has been applied in a limited number of cases, and the long-term outcomes remain unclear.	184–613	6–58	0%	0%	6.50%	The median weight experienced a reduction of 11.5%
Right-opened single muscular flap anastomosis [44]	This technique is both safe and feasible, demonstrating satisfactory outcomes in the prevention of reflux and stricture formation, as well as in the maintenance of nutritional status.	This technique presents certain operational challenges, and its effectiveness in the context of high-located oesophagogastric junction tumors remains uncertain. Further follow-up studies are necessary to assess long-term efficacy.	285.3 ± 71.3	6–24	0%	0%	5%	The mean weight experienced a reduction of 0.8%
“Arch bridge” anastomosis [45]	This technique demonstrates favorable antireflux efficacy and exhibits low operational complexity	This technique has been applied in a limited number of cases, and the long-term outcomes remain unclear.	203%	10%	0%	0%	0%	Not applicable
“コ” shaped single muscular flap anastomosis [46]	The technique exhibits favorable antireflux efficacy, is distinguished by its safety and ease of execution, and can be performed at an elevated position to facilitate anastomosis	This technique has been applied in a limited number of cases, and the long-term outcomes remain unclear.	250 − 290	8 − 10	0%	0%	0%	Not applicable
“Tunnel” anastomosis [47]	This technique reduces surgical complexity and has a good anti-reflux effect.	This technique presents a challenge in executing the complete laparoscopic suture operation, and the long-term outcomes remains unclear.	154 − 523	7 − 14	9.50%	4.80%	9.50%	The median weight experienced a reduction of 9.9%

Limitations of current research

Although studies have demonstrated that muscular flap anastomosis can effectively prevent reflux, its clinical application remains limited by a non-negligible learning curve. Current evidence suggests that achieving proficiency in laparoscopic techniques may require a cumulative experience of 20 to 30 procedures, with inter-surgeon technical variability potentially affecting the consistency of clinical outcomes. Consequently, in low-volume surgical centers or settings without robotic assistance, the precision and broad applicability of this procedure are compromised. These challenges underscore the need for future development of standardized training protocols and simplified surgical techniques to facilitate the safe and widespread adoption of this approach.

The studies included in this study have primarily involved a small number of cases, and the available oncological data are limited. Consequently, the presented results and discussions are constrained, which represents a limitation of this review. In the meantime, owing to the varying quantitative criteria across studies, direct comparisons are not feasible. There is a significant lack of long-term postoperative follow-up data; consequently, few studies have addressed long-term survival outcomes related to innovative surgical techniques. Furthermore, while some reports suggest improvements in nutritional status post-surgery, standardized evaluations regarding enhancements in surgical technique quality and overall quality of life remain insufficient. At the same time, the severity of reflux observed during endoscopy often does not correlate with patients’ subjective symptoms, indicating a dissociation between objective findings and subjective perception.

In light of the current landscape characterized by innovative and increasingly diverse anastomotic techniques, establishing a stable surgical method that garners general consensus presents a considerable challenge. Future research should prioritize multi-center prospective randomized controlled trials to assess the safety and effectiveness of various techniques anastomosis methods. Additionally, evaluating anti-reflux effects and complications related to anastomoses through quality-of-life questionnaires and endoscopic examinations will help address the limitations inherent in retrospective studies while bolstering research reliability.

Moreover, it is imperative to conduct investigations focused on long-term overall survival to analyze how different techniques anastomosis methods impact longevity outcomes.

Conclusions

For patients with early gastric cancer who meet specific criteria, performing proximal gastrectomy can preserve distal gastric tissue, thereby enhancing postoperative digestive and absorption functions as well as nutritional status. With stringent screening of indications, gastroesophageal muscular flap anastomosis stands out as a suitable option for gastroesophageal reconstruction, effectively preventing postoperative reflux. However, establishing it as an “ideal” standard still presents significant challenges. Future research must urgently employ a multicenter, prospective design. With strictly standardized surgical techniques and evaluation systems in place, it is essential not only to validate its long-term anti-reflux efficacy and nutritional benefits but also to systematically evaluate its reproducibility across diverse clinical settings, cost-effectiveness, and overall impact on patients’ quality of life.

Authors’ contributions

Yi-Long Qian: Writing - original darft and visualization. Kai Ye: Writing - original darft and visualization. Chu-Ying Wu: Writing - original darft, Writing - review & editing, conceptualization and funding acquisition. All authors reviewed and agreed to the published version of the manuscript.

Funding

This work was supported by Quanzhou Science and Technology Plan Projects (2024NY033) and Fujian Medical University Sailing Fund General Project (2022QH1117).

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

Not applicable.

Competing interests

The authors declare no competing interests.