Chinese clinical practice guidelines for super minimally invasive surgery of digestive tract tumors

The mode of organ resection and reconstruction that has been used to treat digestive tract tumors (DTTs) can cure the disease. However, it involves the surgical resection of critical structures (such as the cardia, pylorus, and anus) and gastrointestinal reconstruction, which alter the physiological anatomy of the digestive system. These changes often lead to numerous postoperative complications and severely affect the patient's quality of life (e.g., refractory gastroesophageal reflux following proximal gastrectomy, dumping syndrome after subtotal gastrectomy, loss of anal function after low rectal surgery). For the defect of this mode, professor Linghu Enqiang proposed the new mode that was "curing the disease and restoring normal function" in 2016, which was named as this new mode: Super Minimally Invasive Surgery (SMIS). To accomplish various types of SMIS, four operative channels were developed: the natural cavity channel, the tunnel channel, the puncture channel, and the multi-cavity channel. SMIS, with its advantages of minimal trauma and organ function preservation, has been recognized by authoritative domestic and international organizations and has developed rapidly. Based on its clinical value and the need for wider application, there is an urgent need to establish standardized guidelines to guide practice. This guideline was developed by leading organizations such as the SMIS committee of World Endoscopy Organization (WEO) and Chinese Society of Digestive Endoscopy (CSDE), in collaboration with multidisciplinary experts from gastroenterology, general surgery, and pathology. Systematic searches were conducted in nine major databases, including PubMed, Embase, and China National Knowledge Infrastructure (CNKI), for both Chinese and English literature published before 2025. Evidence from randomized controlled trials (RCTs), observational studies, and case series was included, with the quality of evidence and recommendation strength evaluated using the GRADE system (high-level evidence:RCTs; low-level evidence: observational studies). The recommendations were refined through several rounds of expert discussions and voting, and were reported following the AGREE II and RIGHT reporting standards. This guideline has been registered on the PREPARE (Practice Guideline REgistration for transPAREncy; registration number: PREPARE-2024CN1183). This guideline addresses 15 issues related to SMIS treatment for esophageal cancer (EC), gastric cancer (GC), colorectal cancer (CRC), their corresponding precancerous lesions, and precancerous lesions of the duodenal papilla. It provides corresponding recommendations in three main areas: (1) Definitions and principles: SMIS should meet ten core criteria, including organ preservation, complete resection (R0), and sterile procedures. It also standardizes naming conventions (e.g., "Super minimally invasive non-full-thickness resection of lower esophageal squamous carcinoma via the oral cavity"). (2) Surgical recommendations: EC: For early and precancerous lesions, SMIS of non-full-thickness resection (non-FTR) is preferred. For circumferential involvement ≥ 1/2, SMIS via tunnel channel for non-FTR is recommended. If the wound circumference is ≥ 75%, the use of corticosteroids or stents to prevent stenosis is advised. GC: For T1a-T1b stage and precancerous lesions, SMIS non-FTR or full-thickness resection (FTR) is preferred, with individualized plans based on the risk of lymph node metastasis (LNM). CRC: SMIS of non-FTR or FTR is recommended as the first-line treatment for T1a-T1b stage and precancerous lesions. For locally advanced rectal cancer (LARC) that achieves clinical remission after neoadjuvant therapy, SMIS of FTR can be considered to assess pathological remission. Duodenal papilla precancerous lesions: SMIS resection via the oral cavity is preferred. Postoperatively, whether to add pancreaticoduodenectomy and follow-up strategies should be determined based on pathology. (3) Postoperative management: A SMIS treatment cure evaluation system for early gastric cancer (EGC) was established, divided into SMIS-Cure A(cured), SMIS-Cure B (clinically cured), and SMIS-Cure C (surgical reassessment), which guides follow-up. For CRC or precancerous lesions, R0 resection is the standard for cure, and follow-up plans are developed according to risk stratification. This guideline systematically integrates the evidence from SMIS in the treatment of DTTs with expert consensus, establishing a standardized pathway centered on organ function preservation. It shifts the treatment model from "cure first" to "cure-function balance". Its application is expected to reduce overtreatment, improve the patient's quality of life, and provide a framework for future technological iterations and the expansion of indications. It should be continuously optimized with multicenter clinical data and long-term follow-up results to achieve more precise, individualized treatment.