Intraoperative endoscopy: A controversial tool or a necessity in modern esophagogastric surgery?

Abstract

Upper gastrointestinal (UGI) endoscopy has become increasingly popular with the recent advancements in technology and the increase of minimally invasive techniques. UGI endoscopy is indicated for diagnostic, staging, and therapeutic purposes and significantly influences the management of patients with a spectrum of foregut diseases, including esophageal and gastric malignancies, achalasia, and gastroesophageal reflux disease. There is growing evidence that intraoperative UGI endoscopy can be a useful adjunct and a powerful tool to enhance tumor localization, offering a direct evaluation of the surgical reconstruction and identifying potential sources of postoperative complications. However, its widespread utilization has been limited by concerns over cost, accessibility, and sufficient training and expertise. The aim of the current study was to review and elaborate on the available literature while presenting our experience in an academic institution specializing in esophagogastric surgery with intraoperative UGI endoscopy. We focused on the indications, added benefits, and related complications.

Key Words: Upper gastrointestinal surgery; Esophagogastroduodenoscopy; Foregut surgery; Esophagogastric surgery; Intraoperative endoscopy

Core Tip: Endoscopy is indispensable for the evaluation of foregut conditions, supporting the formulation of a tailored plan for each surgical candidate. It provides live detailed visualization of tumor margins while it also enhances staging accuracy and risk stratification. Moreover, its utility in the management of postoperative complications in the hands of the operating surgeon is of paramount importance. Fellowships in upper gastrointestinal surgery underline the role of intraoperative endoscopy and scientific surgical societies are in alignment with the above views.

INTRODUCTION

Technological advancements and modern surgical tools have profoundly transformed the performance of surgeons. Surgery has become less invasive and safer with the utilization of endoscopic tools developed to optimize outcomes. Upper gastrointestinal (UGI) endoscopy is one of these tools that provides clear benefits[1]. It is implemented for both diagnostic and therapeutic purposes[2]. Its application has expanded to include the management of patients with esophagogastric malignancies, achalasia, gastroesophageal reflux disease, and hiatal hernia. Endoscopy provides essential information for accurate disease staging, facilitating a comprehensive assessment of tumor location and size as well as the detection of synchronous lesions[3]. Moreover, endoscopy can validate or decipher ambiguous preoperative imaging for the identification of early-stage tumors, significantly impacting management and surgical planning[4]. Its use during surgery is confirmatory and provides the opportunity to evaluate surgical reconstruction while improving overall safety by identifying potential complications to reduce their occurrence during the postoperative period. The aim of the current article was to present a review of the current indications, relevance, and merits of intraoperative UGI endoscopy in the management of both benign and malignant esophagogastric conditions.

LITERATURE REVIEW

A review was conducted to explore current evidence-based knowledge on the use of intraoperative UGI endoscopy in the setting of esophagogastric surgery. A literature search was performed in PubMed/MEDLINE and Scopus using keywords combined with the Boolean operators OR and AND. The complete search strategy is available in Table 1. Original studies and relevant review articles published in the English language from 2000 until inception (April 2025) were considered eligible for inclusion. The last electronic search was conducted in June 2025. Exclusion criteria included: (1) Inappropriate publication types, including case reports (less than 10 patients included), experimental studies, conference presentations or proceedings, book chapters, research protocols, surveys, guidelines, comments, and errata; (2) Studies published in other languages; (3) Studies on the use of endoscopy in bariatric metabolic procedures; (4) Studies including pediatric patients; (5) Studies investigating the use of therapeutic endoscopy or the impedance planimetry system; and (6) Studies in which the full article was unavailable. The search protocol, article selection, and data extraction were conducted by two authors working independently. Any areas of disagreement were resolved through a case-by-case discussion.

Table 1 Presentation of the complete search strategy.

Database used	Filters	Search term	Number of studies found
PubMed/MEDLINE	English language, publication period 2000-2025	[intraoperative (title/abstract)] AND [(endoscopy (title/abstract) OR gastroscopy (title/abstract) OR esophagogastroscopy (title/abstract)] AND [esophageal carcinoma OR gastric carcinoma OR gastroesophageal junction OR esophagectomy OR gastrectomy OR hiatal hernia OR fundoplication OR achalasia OR myotomy]	367
Scopus	English language, publication period 2000-2025	Title-abstract-keyword [intraoperative AND (endoscopy OR gastroscopy OR esophagogastroduodenoscopy) AND (esophagogastrectomy OR “upper gastrointestinal” OR fundoplication OR myotomy)	71

LITERATURE SELECTION AND INCLUSION PROCESS

The study selection process is presented in detail in Figure 1. After removing duplicates and conducting an initial screen of the title and abstract, 247 articles were examined further with a full-text review. Among them 198 records met the prespecified exclusion criteria, leaving 49 studies eligible for inclusion. Due to the narrative nature of the current review, a selective approach was applied whenever multiple publications were investigating or elaborating on the same topic. As a result, 21 articles originating from our initial search strategy results were included and further analyzed. They were included due to their relevance to our core topics, methodological transparency, and conceptual contribution. Thirty additional articles were used to formulate the backbone of this article and provide supporting information on the analyzed topics.

Figure 1 The Preferred Reporting Items for Systematic reviews and Meta-Analyses flowchart. The presentation of the methodology implemented for selecting the articles studied.

OVERVIEW OF THE USE OF UGI INTRAOPERATIVE ENDOSCOPY IN ESOPHAGOGASTRIC SURGERY

Intraoperative endoscopy offers a unique advantage in surgical practice by providing direct, real-time visualization of internal luminal structures and allowing immediate diagnostic and therapeutic decisions. Its integration into surgical procedures significantly enhances the surgeon’s ability to localize pathology that may not be externally visible or palpable, including small tumors, mucosal lesions, and bleeding sources[5]. The use of endoscopy during an operation is essential to safely complete certain procedures.

Intraoperative endoscopy is instrumental in confirming the integrity and adequacy of surgical interventions. After performing an esophagogastric anastomosis, intraoperative endoscopy can promptly identify leaks, strictures, or insufficient hemostasis[6]. The immediate feedback facilitates intraoperative correction, potentially avoiding the need for reoperation or postoperative interventions. Additionally, intraoperative endoscopy is a useful assistive tool in minimally invasive procedures. In laparoscopic and robotic-assisted surgeries, endoscopy complements the visual field and enhances precision without increasing invasiveness. This synergy supports the broader goals of minimally invasive surgery (i.e., reducing patient morbidity, shortening hospital stay, and accelerating recovery).

Overall, intraoperative endoscopy serves as a powerful adjunct to surgery, merging diagnostic clarity with therapeutic capability. Its use improves surgical accuracy, enhances intraoperative decision-making, and leads to better postoperative outcomes. As surgical techniques evolve, the role of surgical endoscopy continues to expand, offering a versatile and valuable tool across multiple surgical disciplines.

TUMOR DETECTION

Tumor location and extent dictate the surgical management of the UGI tract. The surgical approach should generally be guided by comprehensive preoperative workup. Therefore, modalities including esophagogastroscopy, computed tomography, positron emission tomography, and endoscopic ultrasound play a crucial role. Intraoperative UGI endoscopy can lead to precise identification of the tumor location and its corresponding margins, ensuring that the chosen surgical approach achieves complete removal of the tumor without carelessly sacrificing normal tissues that could facilitate an effective and safe gastrointestinal reconstruction[7-10].

These advantages of intraoperative endoscopy are important when managing tumors of the esophagogastric junction, particularly “true cardia’’ type II junctional carcinomas. According to the Siewert classification, type I lesions are almost universally managed as esophageal carcinomas, whereas type III lesions are managed as gastric carcinomas[11]. The management of Siewert type II lesions has not been well-defined because these tumors have been considered as either esophageal or gastric carcinomas through the years[12]. Accordingly, different approaches have been described, including the transthoracic and the transhiatal esophagectomy, the transhiatal extended total gastrectomy, and the left thoracoabdominal esophagogastrectomy. Currently, there is no consensus to guide the optimal approach, but it should be individualized and tailored to each case. However, in all cases the basic surgical principle of ensuring tumor-free resection margins (R0 resection) should be followed to minimize the risk for disease recurrence and improve overall survival[13,14].

Intraoperative UGI endoscopy has been effectively used to ensure complete tumor removal when laparoscopic total gastrectomy has been selected. There is no tactile feedback nor visual identification of the tumor from the laparoscopic view. A recent retrospective study analyzed 52 patients with type II junctional tumors, who underwent a laparoscopic total or proximal gastrectomy under intraoperative endoscopic guidance[15]. The endoscopist indicated the proximal location of the tumor, and the proximal line of transection was synergistically determined by both the endoscopist and the surgeon. Subsequently, the area was marked laparoscopically, the esophagus was clamped, and the endoscopist confirmed that the tumor was not visible before the stapler was fired. Frozen section analysis confirmed that the margins were histologically negative in all cases when 2 cm from the endoscopic proximal tumor margin was used to define the transection line.

Other researchers elaborated on the combination of endoscopic clipping and intraoperative endoscopy to determine safe surgical margins for patients with gastric cancer[16]. It has been shown that the application of dye on the gastric or esophageal wall can obscure the tumor extension and the surgical planes. Therefore, intraoperative endoscopy is a valuable tool for real-time evaluation of the tumor location and extent in UGI resections.

ANASTOMOTIC ASSESSMENT

After resection it is necessary to reconstruct the digestive tract through anastomosis of the proximal and distal parts. Surgical drains, laboratory results of drainage specimens, and routine postoperative radiography is used to promptly recognize an anastomotic complication, including anastomotic leakage and dehiscence. However, these methods are unable to prevent severe complications.

With endoscopy the mucosa can be evaluated to exclude the presence of ischemic areas prior to initiation of the anastomosis. After the anastomosis, the staple line section can be evaluated for minor defects. Air leaks can be detected when introducing air through the endoscope while the anastomosis is submerged in normal saline[17,18]. Simultaneous intraluminal and extraluminal views of the anastomosis reduce the risk of a possible leak going unnoticed. According to a recent systematic review and meta-analysis on gastric cancer surgery, the intraoperative leak test was associated with a significantly lower rate of postoperative anastomotic leakage and anastomosis-related complications and reoperations[19]. The anastomotic diameter can also be checked endoscopically to rule out stenosis or hemorrhagic foci of the stapling line.

Park et al[20] assessed the efficacy of intraoperative endoscopy in the prevention of early anastomotic complications in patients who underwent gastrectomy for gastric carcinoma. Their retrospective case-control study included 319 patients who underwent different types of gastrectomy (total, distal, proximal) and different types of gastrointestinal reconstructions. All patients had a post-anastomotic intraoperative endoscopy and were compared with a control group who had not undergone intraoperative endoscopy. Positive events were identified in 26 patients (8%), including 2 patients with air leaks who subsequently received reinforcement of the suture line and followed an uncomplicated postoperative course. The combined rate of early anastomotic complications was significantly lower in the group that received intraoperative endoscopy (3.4% vs 8.9%, P < 0.01). No immediate complications related to endoscopy occurred. Despite the study limitations the authors suggested that post-anastomotic endoscopy during gastric cancer surgery has potential to reliably and safely prevent and limit postoperative anastomotic complications.

SUBMUCOSAL TUMORS

Gastric and esophageal submucosal tumors constitute a broad category of neoplasms with variable behavior that ranges from completely benign to highly malignant. They can be distinguished from mucosal-based malignancies with the use of endoscopic ultrasound[21]. Histology of submucosal lesions after endoscopic-guided fine-needle aspiration can be used to identify and differentiate benign lesions from malignant lesions[22]. After diagnosis, surgical excision is the primary treatment, and minimally invasive approaches are appropriate when adequate surgical margins can be achieved. The limitations of laparoscopy can be overcome with the combined use of intraoperative endoscopy, which can localize and ensure safe tumor excision margins, especially in tumors less than 18 mm with a predominant intramural component[23]. In the treatment of leiomyomas, which are the most common benign esophageal tumors, minimally invasive enucleation is recommended[24]. Enucleation can be accompanied by the use of intraoperative endoscopy to insufflate and confirm the mucosal integrity and protect against a potential perforation of the esophagus[25].

ANTIREFLUX AND HIATAL HERNIA SURGERY

Gastroesophageal reflux disease is an increasingly common condition in the Western hemisphere with an estimated prevalence of 27%[26]. Despite the wide application of pharmacologic treatment and newer endoscopic techniques, laparoscopic repair and construction of a complete or partial fundoplication is the primary treatment for chronic refractory reflux. Most patients reported a long-term significant improvement of their symptoms with few cases experiencing recurrence or new symptoms, including dysphagia and bloating[27].

Intraoperative UGI endoscopy is critical for the safe and effective completion of this technically demanding operation. Intraoperative endoscopy visualizes the anatomical landmarks (i.e., the gastroesophageal junction) around which the wrap will be constructed. Although surgeons are generally accurate when determining the position of the junction, Chang et al[28] determined that the junction was more than 1 cm cephalad when comparing the endoscopic position and the surgical estimation in 10% of cases. Inadvertently placing the wrap over the stomach can produce a “slipped” wrap in which patients may experience postoperative dysphagia.

Accurate identification of the Z-line with endoscopy can help surgeons mobilize the abdominal esophagus when needed and correctly position the wrap on top. A true “short esophagus” is present in 57% of type III-IV hiatal hernia cases and must be recognized and addressed[29,30]. The mechanism, which is independent of the surgical technique, behind hiatal recurrence is the tension applied to the esophagogastric junction and the gastric fundus over the crura[31]. A shorter esophagus results in more applied tension and is a key factor leading to recurrence. Intraoperative endoscopic-guided measurement of the intra-abdominal esophageal length is an objective method for recognizing these patients. The surgeon can then proceed with the Collis-Nissen gastroplasty technique to establish a tension-free repair[32]. Furthermore, intraoperative endoscopy can tailor the repair, ensuring no esophageal kinking nor stenosis due to either a tight valve or a tight cruroplasty.

Many surgeons are still using a bougie to calibrate the repair. In our practice we replaced the bougie with the endoscope. We can easily confirm that our loosely constructed Nissen fundoplication, over a crural repair that is “kissing” the empty esophagus, is patent and free of stenotic areas. Assessing the symmetry of the wrap and the tightness of the valve is also facilitated by endoscopic evaluation under retroflexion[33-36]. Intraoperative UGI endoscopy is invaluable for reoperations. The presence of dense adhesions can significantly obscure the operative field, and establishing the correct planes is extremely important.

ACHALASIA

Intraoperative endoscopy plays a critical role in the surgical management of achalasia, which is characterized by impaired lower esophageal sphincter relaxation and a lack of peristalsis of the esophageal body. The cutting-edge endoscopic technology, peroral endoscopic myotomy, is used as the primary treatment option in selected patients with achalasia. Laparoscopic Heller myotomy (current gold standard) is also widely used and provides significant long-term symptomatic improvement in many patients[37]. It requires precise division of the muscular layers above and below the esophagogastric junction to relieve the functional obstruction. Due to the technical demands of laparoscopic Heller myotomy and the functional nature of achalasia, intraoperative endoscopy contributes to procedural success and improved patient outcomes.

Intraoperative endoscopy allows direct visualization of the esophageal lumen during myotomy to confirm adequate length and depth of muscle division. This real-time feedback is essential to optimize the effectiveness of the procedure and to prevent an incomplete or failed myotomy, resulting in persistent dysphagia. Particularly, intraoperative endoscopy facilitates precise localization of the squamocolumnar junction, thereby guiding the proper length of the myotomy. It typically extends proximally for a minimum of 5 cm on the esophageal wall and distally for a minimum of 2 cm on the gastric wall. Additionally, endoscopy provides an immediate assessment of luminal patency and esophageal distensibility, both of which serve as surrogate markers of an adequate myotomy.

Furthermore, intraoperative endoscopy confirms the presence of an intact esophageal mucosa prior to closure. Missed esophageal perforations can lead to life-threatening mediastinitis and sepsis[38]. These complications are mitigated by endoscopic insufflation and an intraoperative leak test. In selected cases the surgeon can also identify and promptly manage any mucosal tears, bleeding, or anatomical anomalies, enhancing safety of the operation and reducing the likelihood of postoperative morbidity and the need for revisional procedures.

Current guidelines and multiple studies on the technical details of a laparoscopic Heller myotomy recommend intraoperative endoscopy[39-42]. However, there are limited data regarding the impact of intraoperative endoscopy on perioperative outcomes. A recent retrospective study involving 61 patients who underwent laparoscopic Heller myotomy compared outcomes between patients who did or did not undergo intraoperative endoscopy[43]. Patients in the group without intraoperative endoscopy were more likely to undergo a UGI contrast series postoperatively. The authors found no differences between the groups in terms of complications, postoperative leak rates and myotomy failure. All mucosal perforations were recognized and repaired laparoscopically irrespective of the use of intraoperative endoscopy. The authors concluded that routine use of intraoperative endoscopy had little effect on patient outcomes after laparoscopic Heller myotomy. Nonetheless, they recommended the implementation of endoscopy to guide the extent of myotomy, especially when the surgeon felt uncomfortable with the anatomy, during reoperation cases, or to confirm or exclude a suspected perforation.

ESOPHAGEAL DIVERTICULA

Epiphrenic esophageal diverticula are pulsion diverticula located within 10 cm of the esophagogastric junction. When they are large and symptomatic, laparoscopic diverticulectomy is indicated[44]. It is debated whether Heller myotomy with antireflux fundoplication is required after diverticulectomy, but it can be investigated with endoscopy. Esophageal manometry is often difficult to perform but essential to determine the categorization of the diverticulum and guide management. Guiding manometry with endoscopy can reduce the surgeon’s effort and lead to safer surgical planning[45]. Intraoperative endoscopy is also profoundly beneficial for locating the margins of the diverticulum, ascertaining its relationship with the esophagogastric junction, and checking the staple line for potential leaking. Additionally, when the esophageal lumen narrows after the amputation of the diverticulum, a myotomy with partial fundoplication may be prudent.

COMPLICATIONS

Despite the well-documented benefits of intraoperative endoscopy, complications are inevitable. Complications range from bleeding to life-threatening perforations and can arise despite multiyear expertise[46]. The most serious adverse event is iatrogenic perforation of the gastrointestinal tract. The incidence of perforation increases in patients with inflamed, fibrotic, or previously operated tissues in which the integrity of the wall may be compromised[47]. Although uncommon, perforation can lead to intra-abdominal contamination, sepsis, and the need for additional surgical repair, thereby prolonging operative time and increasing postoperative morbidity.

Hemorrhagic complications can also occur[48]. While bleeding is manageable with endoscopic or surgical hemostasis, it can obscure the surgical field, complicate visualization, and necessitate transfusion or conversion to an open surgery in rare cases. Another complication can arise after the use of gas. Barotrauma or air embolism are rare but serious complications, especially in the presence of mucosal breaches or unrecognized transmural injury. The adoption of carbon dioxide over air insufflation has mitigated this risk to its rapid absorption.

CONCERNS AND LIMITATIONS

Intraoperative UGI endoscopy differs from classic endoscopy because the patient is under general anesthesia with orotracheal intubation. This scenario increases the difficulty of the procedure due to the limitations of the orotracheal tube size. Additionally, during surgery the position varies (supine, lateral, semi-prone, or Trendelenburg) necessitating the patient’s repositioning to grant endoscope access and facilitate effective endoscopy. The endoscopic tower must conform to the spatial arrangement of the operating theatre and simultaneously satisfy the surgeon’s preference and ergonomic needs[49]. The distension of the abdomen during endoscopy, which allows better visibility and access of the endoscope, may obstruct the surgical approach. The insufflation flow rate and pressure must be regularly assessed to avoid further complications.

Due to these technical difficulties, intraoperative UGI endoscopy should only be utilized by surgeons who have adequate training and appropriate certification. Inadequate training or limited experience may result in incomplete evaluations, technical errors, or failure to recognize complications in a timely manner. Institutional protocols should ensure that intraoperative endoscopy is performed by or in collaboration with an experienced endoscopist supported by the appropriate equipment and infrastructure to promptly manage any complications. Experience in intraoperative endoscopy can be achieved through structured residency curricula, fellowships in specialized UGI centers, and dedicated training programs by international surgical societies. Educational programs like the Fundamentals of Endoscopic Surgery developed by the Society of American Gastrointestinal and Endoscopic Surgeons combine a structured curriculum with validated skills assessment to determine proficiency[50]. Implementing intraoperative endoscopy to daily surgical practice requires credentials that conform to standards set by professional society guidelines[51]. The operating theatre personnel must also have the appropriate experience with the system setup, function, aftercare, sterilization, and troubleshooting of the equipment and associated hardware.

CONCLUSION

Intraoperative endoscopy is an invaluable tool for the evaluation of foregut conditions. It provides real-time information of tumor margins and extension, while enhancing staging accuracy. It also assesses the integrity of the performed anastomosis and evaluates the antireflux valve geometry. In addition, it can establish myotomy safety, preventing associated postoperative complications and adverse events. Its unique advantage in surgical practice lies in its ability to allow for both diagnostic and therapeutic decision making; but, moreover, it can effectively manage complications. International fellowship programs in UGI surgery should provide training opportunities for intraoperative endoscopy with input and support from global scientific surgical societies.