With changing dietary habits and the increasing adoption of colorectal cancer screening, the incidence of low rectal cancer is on the rise in China. In Shanghai alone, the annual growth rate is estimated at 4.2% to 4.6%, with 70% to 80% of rectal cancers classified as mid-to-low rectal tumors. Despite advancements in surgical techniques, anastomotic leakage remains a critical challenge, with an incidence ranging from 1.6% to 20%. The risk is particularly pronounced in patients who have undergone neoadjuvant chemoradiotherapy, leading to severe complications such as high mortality rates, serious infections, loss of anal function, and an increased risk of tumor recurrence.

At the recent 9th Annual Meeting of the Chinese Medical Doctor Association’s Colorectal Oncology Committee, Dr. Zheng Lou from Changhai Hospital, Naval Medical University, delivered a presentation titled “Integrative Approaches in the Prevention and Treatment of Anastomotic Leakage Following Low Rectal Cancer Surgery.” Drawing from extensive clinical experience and research, his team has made significant strides in addressing this long-standing surgical challenge, offering new hope for improved patient outcomes.

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Current Surgical Approaches and the Challenge of Anastomotic Leakage in Low Rectal Cancer

With the continuous evolution of surgical techniques for low rectal cancer—including abdominoperineal resection (APR), Dixon’s procedure, and intersphincteric resection (ISR)—concerns about postoperative anal function remain a significant challenge. The Chinese Journal of Gastrointestinal Surgery recently published expert consensus on ISR, offering detailed insights into its technical aspects, but functional outcomes remain a primary concern.

Under the leadership of Professor Wei Zhang, Professor Lou’s team has spent over a decade refining functional-preserving surgical techniques for low rectal cancer. They have established a comprehensive system outlining indications, key considerations, and strategies for preventing complications. Their standardized surgical protocol, published in the Chinese Journal of Gastrointestinal Surgery, has provided a valuable reference for specialists in the field.

However, the increasing surgical volume has highlighted the growing challenge of anastomotic complications, particularly anastomotic leakage, one of the most severe postoperative risks. Occurring in 1.6% to 20% of cases, its incidence is even higher in patients who have undergone neoadjuvant chemoradiotherapy. Anastomotic leakage can lead to severe pelvic and abdominal infections, increased mortality risk, delayed postoperative adjuvant therapy, and compromised oncologic outcomes. In many cases, excessive fibrosis around the rectum and anal canal can significantly impair anal function, often resulting in the permanent need for a stoma. Even when stoma reversal is attempted, residual functional deficits may necessitate re-stoma formation, making the transition from acute leakage to chronic leakage particularly difficult to manage.

Risk Factors and the Search for Solutions

Research suggests that anastomotic leakage is primarily influenced by anastomotic tension, vascular supply, and tissue healing capacity. While surgical techniques can address issues related to tension and blood flow, healing capacity is largely patient-dependent and difficult for surgeons to control. Factors such as male sex, obesity, and preoperative bowel preparation status can significantly affect outcomes.

Professor Lou’s team conducted a retrospective analysis of 319 patients with mid-to-low rectal cancer who did not undergo prophylactic stoma creation. Their findings identified several independent risk factors for anastomotic leakage, including tumors located ≤7 cm from the anal verge in male patients, preoperative neoadjuvant chemoradiotherapy, KRAS gene mutations, and diabetes mellitus. Even in the absence of these risk factors, 2.5% of patients still developed anastomotic leakage. When two or more risk factors were present, the incidence climbed to 13.8%, posing a significant challenge, particularly for high-volume surgical centers.

A New Direction: Integrating Traditional and Western Medicine

Recognizing that tissue healing capacity remains a critical limiting factor, Professor Lou’s team has pioneered an integrative approach combining traditional Chinese medicine with modern surgical techniques to improve anastomotic healing. By leveraging traditional herbal formulations known for their pro-healing and anti-inflammatory properties, their research explores how these therapies can enhance microcirculation, promote fibroblast activity, and reduce local inflammation, thereby mitigating the risk of leakage.

While challenges remain, this integrative strategy represents a promising new frontier in colorectal surgery, offering a potential paradigm shift in postoperative care. Professor Lou’s team continues to refine their approach through clinical trials and translational research, aiming to provide a scientifically validated, evidence-based solution to one of the most persistent complications in rectal cancer surgery.

As research in surgical innovation and integrative medicine continues to advance, anastomotic leakage may no longer be an unavoidable complication but rather a manageable risk with tailored, multidisciplinary interventions.

Multidensional Prevention Strategies to Reduce the Risk of Anastomotic Leakage

Faced with the serious challenge of anastomotic leakage, Dr. Zheng Lou and his team have actively explored various strategies through extensive clinical practice and research. Their findings have led to the development of several effective prevention strategies:

• Optimizing surgical techniques and reinforcing the anastomosis A retrospective analysis of over 6,000 cases of mid-to-low rectal cancer at their center highlighted the significant role of anastomotic reinforcement in reducing leakage. Key technical refinements include ensuring meticulous tissue handling, complete mesorectal dissection, and preventing excessive fat infiltration into the anastomotic site. When closing the distal rectum, the team recommends using no more than two staple cartridges to minimize the risk of leakage. For reinforcement, barbed sutures are commonly used to continuously suture the intersection of the linear stapler and the anastomotic device, which is the most vulnerable area. In low rectal cancer surgeries, reinforcing the anterior anastomotic site is relatively straightforward, but when the suture line extends into the anal canal, reinforcing the posterior wall becomes more technically demanding. Surgeons must carefully control suture spacing and tension to avoid compromising blood supply. Clinical practice has shown that after continuous suturing, the color of the anastomotic bowel wall remains unchanged, effectively reducing the incidence of leakage.

• Elevating and reconstructing the pelvic peritoneum Many centers do not routinely reconstruct the pelvic peritoneum following mid-to-low rectal cancer surgery, which can negatively impact anal function. In conditions such as rectal prolapse or chronic constipation, the rectal anterior concavity may extend too low, with the peritoneal reflection reaching the anal canal plane. In normal pelvic anatomy, however, the peritoneal reflection is positioned 7–8 cm above the anal verge, and restoring this structure is critical for preserving anal function. Additionally, pelvic reconstruction helps isolate the pelvic cavity from the free abdominal cavity, which can prevent abdominal contamination in the event of an anastomotic leak, thereby reducing the need for unplanned reoperations (Grade C leaks). Professor Lou’s team has adopted a U-shaped suture technique from right to left for pelvic elevation and reconstruction. Their study showed that among patients who underwent pelvic reconstruction, only one required reoperation, compared to seven cases in the control group, where the reoperation rate approached 90%. Furthermore, reconstructing the pelvic floor prevents small bowel herniation around the neorectum, thereby reducing the risk of radiation enteritis following adjuvant therapy.

• Preventive stoma creation Protective stomas play a crucial role, particularly for patients undergoing neoadjuvant chemoradiotherapy. While some literature debates whether diversion significantly reduces the incidence of anastomotic leakage, Professor Lou’s center has found strong supporting evidence for its benefits. Neoadjuvant therapy increases the risk of leakage, and the RECTODES study confirmed that a protective stoma can effectively reduce this risk. By diverting fecal flow, a temporary stoma minimizes contamination of the anastomosis and enhances the effectiveness of infection control and drainage measures. In 2007, their data showed a 4% reduction in anastomotic leakage rates with protective stomas. In 2022, the Chinese Medical Doctor Association’s Colorectal Surgeon Committee issued the China Expert Consensus on Preventive Stoma in Mid-to-Low Rectal Cancer Surgery, offering 17 key recommendations covering surgical and nursing considerations. This consensus provides clear guidance for clinical teams, ensuring more effective implementation of stoma-related protocols.

• Exploring new therapeutic strategies to avoid surgical risks Professor Lou’s team has been conducting the CHOICE series of immunotherapy-based studies to explore surgical alternatives for patients with early-stage rectal cancer (T1–T3N0–N1) who are MMR-proficient and would otherwise require radical resection with potential loss of anal function. A study published in International Surgery included 25 patients, of whom 23 completed treatment. Among them, 10 achieved complete clinical remission (CR), and 5 had near-complete remission. In the CR group, a watch-and-wait strategy was adopted, while 4 underwent local excision and 8 received sphincter-preserving surgery. Results showed that 63.4% of patients avoided anastomotic leakage, with a 95.5% organ-preservation rate. As research advances, this approach could allow more patients to avoid major surgery, stoma formation, and related complications.

Integrating Traditional and Western Medicine to Offer New Hope for Anastomotic Leakage Patients

Even with multiple preventive strategies in place, anastomotic leakage can still occur, making timely and effective treatment essential. In the acute phase, Western medicine plays a fundamental role in infection control and drainage, but Traditional Chinese Medicine (TCM) also has a significant role in supporting recovery. By strengthening the patient’s overall health and immune function, TCM therapies help promote tissue healing. Herbal washes are used to cleanse the wound, remove necrotic tissue, and facilitate the regeneration of healthy tissue, accelerating anastomotic healing.

When anastomotic leakage progresses to a chronic stage, conventional treatments often yield suboptimal results, as fistulas can epithelialize, leading to persistent symptoms and complications. In 2006, Italian scholar Meinero introduced the video-assisted anal fistula treatment (VAAFT) technique, which was first clinically reported in 2011. This minimally invasive approach enables precise identification and treatment of fistula tracts while preserving anal function, marking the beginning of a new era in the precision treatment of complex fistulas.

Dr. Zheng Lou’s team has innovatively applied the VAAFT technique to the treatment of chronic anastomotic leakage following low rectal cancer surgery. One case involved a patient in his seventies who had undergone sphincter-preserving surgery for low rectal cancer. After confirming the presence of an anastomotic leak, the team used a specialized irrigation system through the anus to locate the fistula opening. They then entered the fistula tract, using a brush to remove necrotic tissue and epithelialized lining. An electrocautery probe was applied to ablate and cauterize the affected tissue while simultaneously sealing the defect with bio-protein glue. Postoperatively, the patient received TCM-based rectal retention enemas using Kangfuxin solution, an extract derived from Periplaneta americana known for its wound-healing properties.

After two months of treatment, fistulography confirmed successful closure of the fistula, with only a small epithelialized opening remaining and normal surrounding mucosa. The patient has remained recurrence-free for nearly three years, with no signs of tumor progression or functional impairment. This breakthrough, published last year in the Chinese Journal of Gastrointestinal Surgery, marks the first domestic study on the application of VAAFT in this context, fully demonstrating its unique advantages in managing chronic anastomotic leakage.

Ultimately, the prevention and treatment of anastomotic leakage after low rectal cancer surgery are not just technical challenges but also require a paradigm shift in clinical thinking. Through surgical innovation, the integration of traditional and Western medicine, and multidisciplinary collaboration, Professor Lou’s team has developed a comprehensive solution to this complex issue. As precision medicine and intelligent technologies continue to advance, patients with low rectal cancer can look forward to improved survival and a higher quality of life.

Expert Profile: Dr. Zheng Lou

Affiliation: Changhai Hospital, Naval Medical University Position: Deputy Director, Department of Colorectal Surgery, Changhai Hospital

Professor Lou holds multiple leadership roles in national and regional medical associations, including:

• Director of the Editorial Board, Oncology Medicine Channel
• Director of Surgical Education, Changhai Hospital’s National Specialist Physician Training Program
• Academic Member, Chinese Academy of Colorectal Surgery
• Vice Chair, Integrative Medicine and Colorectal Oncology Group, Chinese Medical Doctor Association
• Vice Chair, Sphincter-Preserving and Functional Rehabilitation Group, Chinese Medical Doctor Association’s Colorectal Surgeon Committee
• Member, Robotic Surgery Group, Chinese Medical Doctor Association’s Colorectal Oncology Committee
• Member, Colostomy Group, Chinese Medical Doctor Association’s Colorectal Surgeon Committee
• Member, Multidisciplinary Team Group for Colorectal Cancer, Chinese Medical Doctor Association
• Member, Surgical Information Dissemination and Education Expert Group, Chinese Medical Doctor Association’s Surgery Committee
• Member, CACA Colorectal Cancer Science and Education Committee
• Member, CACA Colorectal Cancer Rehabilitation Committee
• Member and Secretary, Shanghai Clinical Quality Control Center for Colorectal Surgery
• Vice Chair, Colorectal Specialty Committee, Shanghai Association of Integrative Medicine
• Standing Member, Minimally Invasive Gastrointestinal Oncology Committee, Shanghai Anti-Cancer Association
• Member, Metastatic Colorectal Cancer Group, Shanghai Anti-Cancer Association
• Member, Colorectal Surgery Group, Shanghai Medical Association’s General Surgery Committee
• Member, Medical Robotics Committee, Shanghai Medical Doctor Association