Management of Colorectal Anastomotic Leaks With Endoluminal Vacuum Therapy: A Pragmatic Summary of the Evidence and Definition of Clinical Practices for Patient Selection, Technique, and Follow-up

Anastomotic leak (AL) remains one of the most feared complications after colorectal surgery, with significant implications for both short- and long-term outcomes. Reported incidence rates vary widely (0%–19%) depending on patient comorbidities, tumor location, surgical technique, and institutional practices.1–4 Notably, left-sided colorectal anastomoses, particularly those located deep within the pelvis, are disproportionately affected, accounting for approximately 75% of reported ALs.3 AL is associated with a wide range of adverse consequences, including increased morbidity, higher reoperation rates, prolonged hospitalization, permanent stoma formation, and elevated perioperative mortality.5,6 Beyond immediate complications, AL has been independently linked to delayed or omitted adjuvant therapy, potentially compromising oncologic outcomes, particularly in stage II and III rectal cancer.7 These downstream effects underscore the critical importance of prevention and early recognition. Diagnosing AL can be challenging in the early postoperative period, as clinical signs may be subtle or nonspecific. Suspicion often arises from systemic indicators such as fever, tachycardia, and leukocytosis, sometimes accompanied by localized abdominal pain or feculent discharge from surgical wounds or drains.3 Diagnostic accuracy is further limited in patients receiving neoadjuvant chemoradiation, where the inflammatory response may be blunted. Contrast-enhanced CT remains the diagnostic modality of choice, typically demonstrating extraluminal gas, perianastomotic collections, or pelvic abscesses.4 In equivocal cases, water-soluble contrast enema or flexible endoscopy may provide additional anatomical detail. Management strategies depend on clinical stability, contamination extent, and anatomical leak characteristics. Unstable patients and those with diffuse peritonitis require urgent reoperation, usually involving anastomosis takedown, peritoneal lavage, and fecal diversion via loop ileostomy or end colostomy.8,9 Conversely, in hemodynamically stable patients with localized abscesses or contained leaks, nonoperative approaches may be viable. These may include broad-spectrum antibiotics, image-guided percutaneous drainage, and, in select cases, transanal washout or endoluminal vacuum therapy (EVT).8–10 Despite available management options, outcomes remain variable and depend heavily on early detection, multidisciplinary coordination, and timely intervention. Given the growing preference for bowel continuity and functional preservation, minimally invasive strategies like EVT are gaining momentum in contemporary practice. This article outlines the potential benefits of EVT in colorectal AL. PATIENT POPULATION AND RISK FACTORS AL is a multifactorial complication influenced by patient-, disease-, and treatment-related variables. Several well-established risk factors have been consistently associated with AL, including male sex, obesity, prior pelvic radiation, diabetes mellitus, and peripheral vascular disease.1 Male sex and obesity may reflect technical and anatomic challenges, such as a narrow pelvis or increased visceral fat, which can hinder dissection, visualization, and secure anastomotic construction. The use of neoadjuvant chemoradiation further compromises tissue healing via microvascular injury and suppression of fibroblast activity. Additional risk factors include emergency surgery, intraoperative hypotension, malnutrition, hypoalbuminemia, chronic corticosteroid use, and active inflammatory conditions such as Crohn’s disease. These not only predispose patients to leak development but also influence the clinical severity and management of the complication. For example, patients with prior pelvic radiation or multiple previous operations often have reduced healing capacity and may be less tolerant of reoperation. Table 1 summarizes risk factors. TABLE 1. - Categories of risk factors associated with anastomotic leaks related to patient features, disease characteristics, or treatment Risk factor Evidence/rationale Patient-related factors Male sex Narrow male pelvis may increase technical difficulty Obesity (BMI >30) Increased visceral fat impairs visualization and tissue handling Diabetes mellitus Impaired microvascular perfusion and wound healing Smoking Vasoconstriction and impaired tissue oxygenation Malnutrition/hypoalbuminemia Poor healing capacity and immune dysfunction Advanced age Reduced physiologic reserve and comorbid burden Peripheral vascular disease Impaired perfusion to anastomotic site Disease-related factors Low rectal tumor Technically challenging low pelvic anastomosis Neoadjuvant chemoradiation Mucosal damage and microvascular injury Emergency surgery Lack of optimization and hostile surgical field Perforated or obstructing tumor Inflamed tissues and contamination increase risk Treatment-related factors Intraoperative blood loss or hypotension Compromised anastomotic perfusion Inadequate vascular supply Ligation of IMA close to origin may reduce flow Tension on anastomosis Compromises healing and integrity No diversion (in low rectal anastomosis) Protective stomas reduce clinical impact of minor leaks IMA = inferior mesenteric artery. Despite the clinical importance of AL, there is currently no universally accepted definition or classification system, thus contributing to wide variability in how leaks are diagnosed, reported, and managed across institutions.4 In response, an international expert panel recently introduced a consensus framework specifically for patients undergoing left-sided colorectal resection for cancer.5 This initiative promotes early detection, structured risk stratification, and standardized perioperative practices to reduce variability and improve outcomes. Section Summary AL is driven by a combination of patient, disease, and treatment factors. Key risk factors include male sex, obesity, diabetes, prior radiation, and malnutrition. Technical challenges and impaired healing mechanisms increase leak risk and complicate management. Emergency surgery and chronic inflammation further heighten susceptibility to AL. A recent international consensus proposes a standardized framework to improve detection and care. EVT: MECHANISTIC RATIONALE AND EVOLVING ROLE IN AL MANAGEMENT EVT has emerged as a promising minimally invasive strategy for managing ALs, particularly in clinically stable patients with contained defects.11–13 EVT applies the core principles of negative pressure wound therapy, long used in external wound management, to the intraluminal environment.14 In this technique, continuous negative pressure (typically –125 to –150 mm Hg) is delivered via a polyurethane sponge placed directly at the site of the anastomotic defect. This pressure promotes fluid drainage, collapse of septic cavities, reduction in interstitial edema, and stimulation of angiogenesis and granulation tissue formation.15,16 Unlike conventional percutaneous drainage, EVT applies suction directly within the GI lumen, enabling progressive wound contraction and epithelialization.11,14 This mechanism is particularly advantageous in low rectal leaks, where traditional reoperative pelvic surgery has high morbidity and where sphincter preservation remains a key clinical goal.17,18 Despite its clinical promise and growing body of supportive evidence, the adoption of EVT remains inconsistent, largely due to variability in clinician expertise, institutional familiarity, and logistical resources. The lack of standardized guidelines for patient selection, technical protocol, and implementation has led to significant heterogeneity in outcomes. Addressing these barriers will be essential to fully integrate EVT into evidence-based colorectal surgical pathways and ensure equitable access to this novel approach. Device Components, Performance, and Availability of Commercial and Custom-Made EVT Systems Several commercial EVT systems, including Endo-SPONGE (B. Braun, Melsungen, Germany), Renasys Go (Smith & Nephew, London, United Kingdom), and Redovac (B. Braun), have been specifically engineered for intraluminal application in the management of colorectal ALs. However, access to these systems remains largely limited to Europe. Regulatory barriers, high costs, and limited global distribution have hindered their broader adoption in North and South America, Asia, and other regions. As a result, custom-made EVT assemblies have been developed to bridge this accessibility gap. Both commercial and custom systems typically consist of a medical-grade polyurethane sponge affixed to a flexible drainage catheter, connected to an external vacuum device capable of delivering continuous negative pressure. Commercial kits often include dedicated insertion tools such as obturators, sheaths, and endoscopic guidance accessories, allowing for more precise and reproducible placement under direct visualization (Fig. 1).FIGURE 1.: Braun‘s Endo-SPONGE system. The commercially available kit includes a polyurethane sponge, insertion catheter, and vacuum drainage system designed for endoluminal negative pressure therapy.Commercial EVT systems offer several advantages, including standardized device architecture, calibrated pressure regulation, and manufacturer-provided technical instructions. These features may contribute to a shorter learning curve, enhanced procedural consistency, and improved technical outcomes. Clinical success, defined as complete cavity healing or resolution without surgical reintervention, has been reported in 70% to 91% of cases in high-volume European centers using the Endo-SPONGE.18,19 Complication rates, including mucosal erosion and bleeding, remain low when procedures are performed under endoscopic guidance by experienced teams. Despite their technical strengths, broader adoption of commercial EVT systems remains constrained by access limitations and regional disparities in availability. Addressing these challenges will require continued innovation, policy harmonization, and international collaboration to support equitable dissemination of this technology. Custom-Made EVT Devices Custom-made EVT systems, typically constructed from open-cell foam (eg, 3M Whitefoam) in combination with nasogastric or suction tubing (Fig. 2), offer a practical and accessible alternative in clinical settings where commercial EVT kits are unavailable.20–22 Multiple case series and cohort studies have demonstrated that, when used by experienced teams, these improvised systems can achieve clinical success rates comparable to those of standardized commercial devices.FIGURE 2.: Assembly and clinical placement of a custom-made endoluminal vacuum-assisted device. A, A medical-grade open-cell sponge is sutured to a nasogastric tube that has been perforated to allow drainage, with the holes fully enveloped by the foam. B, A flexible guidewire may be introduced using the Seldinger technique to facilitate accurate device placement under endoscopic guidance. C, Final positioning includes the establishment of an external vacuum setup, with tubing anchored securely to the patient’s skin, completing the closed-loop negative pressure system.A notable example is the custom Endo-VAC system described by Pinilla et al; the system uses 3M Whitefoam, a standard nasogastric tube, and a conventional hospital-grade vacuum pump.15 This configuration effectively mirrors the core therapeutic principles of commercial EVT platforms while enabling broader access in resource-constrained institutions. The authors detail a 10-step protocol for the assembly and deployment of the device, including instructions for constructing an external vacuum station. Despite their potential, custom-built EVT systems are inherently more operator-dependent, lack regulatory oversight, and may pose challenges related to pressure calibration, material biocompatibility, and reproducibility. Although many successful adaptations have been reported, the absence of standardized, validated protocols highlights the pressing need for practical clinical guidelines to promote safety, ensure procedural consistency, and facilitate broader adoption.23 Section Summary EVT is a minimally invasive option for colorectal ALs, promoting drainage and healing via negative pressure. It is especially useful in low rectal leaks, where reoperation risks sphincter damage. Commercial systems like Endo-SPONGE offer standardized tools but face cost and availability barriers. Custom-made devices using hospital materials provide a viable, effective alternative. Wider adoption depends on clinician training, standardized protocols, and global accessibility. TECHNICAL CONSIDERATIONS, PROCEDURAL SETUP, AND PATIENT SELECTION FOR EVT Ideal candidates for EVT are patients with low colorectal anastomoses, localized pelvic collections, and stable hemodynamic status.13,24,25 EVT is most commonly performed in the endoscopy suite. However, in cases of extensive contamination requiring thorough transrectal pelvic lavage before EVT initiation, the procedure is more appropriately performed in the operating room. Contraindications to EVT include dehiscence or collections not confined to the pelvis, more commonly observed in high (proximal) anastomoses, generalized peritonitis, hemodynamic instability, and complex fistulizing disease.13,26 Strict adherence to these selection criteria is essential to guide therapeutic decision-making, enhance treatment efficacy, and minimize the risk of failure (Table 2). TABLE 2. - Stepwise algorithm for initiating and managing EVT in colorectal anastomotic leaks Step Decision point Recommended action 1 Leak diagnosis confirmed via CT or endoscopy Assess hemodynamic status and leak characteristics 2 Generalized peritonitis? Yes → Proceed to surgical reoperationNo → Go to step 3 3 Confined pelvic abscess? Yes → Consider EVTNo → Consider alternative drainage 4 Anastomosis accessible endoscopically? Yes → Proceed with EVT setup and sponge placementNo → Reassess surgical vs percutaneous options 5 Sponge exchange every 2–3 d Monitor healing endoscopically; adjust sponge size 6 Cavity healed or plateau reached Remove sponge; reassess for stoma reversal EVT = endoluminal vacuum therapy. Timing of EVT Initiation and Treatment Algorithms Early initiation of EVT, ideally within 3 to 6 weeks after surgery, has been associated with improved anastomotic healing and increased rates of stoma reversal.24,27 The most favorable outcomes have been reported when EVT is commenced between postoperative days 15 and 21, achieving defect closure rates of up to 87%.27–30 To optimize outcomes, standardized postoperative care pathways should emphasize early detection of ALs and timely multidisciplinary evaluation. Early recognition and intervention are essential to ensure that patients are eligible for EVT within the optimal therapeutic window. Table 3 provides key clinical pearls related to timing and procedural setup. TABLE 3. - Summary of practical considerations and evidence in EVT for colorectal anastomotic leaks Decision factors Key selection for stable patients with low colorectal anastomosis and contained pelvic not for bowel or peritoneal leaks Timing EVT within d to optimize and stoma due to or Technical precise sponge continuous suction to –150 mm Hg) and exchange every 2–3 d for sponge granulation and complications (eg, bleeding, EVT = endoluminal vacuum therapy. Sponge and The of EVT is on precise sponge typically performed under endoscopic or transanal guidance. The sponge should be to the anastomotic defect or cavity negative pressure distribution while the risk of mucosal Recommended negative pressure settings typically range from –125 to –150 mm depending on defect cavity location, and tissue To the risk of sponge or secure external of the vacuum tubing is essential and should be consistently the of Sponge Sponge are every to to promote granulation tissue formation, effective negative pressure and minimize the risk of clinical protocols a of 3 to a treatment from 1 to 6 In clinically stable exchange may be that close clinical endoscopic is to ensure treatment and and endoscopic is essential to sponge progressive cavity and the development of granulation tissue (Fig. early detection and of technical that may treatment challenges include the endoscopic of endoluminal vacuum therapy. A, of the defect. B, and sponge C, of negative often due to leaks or tubing This typically sponge or optimization of the external between the sponge and cavity which can therapy This is commonly by the sponge or its by or Management strategies include or of the tubing no clinical or endoscopic is observed after approximately 6 weeks of therapy, should be to alternative management strategies such as surgical endoscopic or fecal Section Summary EVT is for stable patients with accessible leaks and should be within 3 to 6 weeks for optimal outcomes. sponge placement under endoscopic or transanal guidance and negative pressure to –150 mm Hg) are should be every to with protocols for select under close endoscopic early detection of such as leaks, tubing or cavity no is after 6 alternative such as surgery or should be The complication associated with EVT is approximately with the most reported adverse including anastomotic and In a cohort of et reported a of abscesses after EVT, close for at 2 A further a of pelvic the need for anastomotic as the most in of cases, by formation, and In the of patients developed low resection at 3 endoscopic for anastomotic Despite these EVT cavity closure and stoma reversal in of However, a notable developed to long-term bowel The reported a incidence of to delayed EVT complications, less have been observed with prolonged sponge often due to sponge adherence to granulation Given the risk of long-term functional including bowel dysfunction and of is should be of the potential complications, and implications associated with Section Summary EVT has a complication of with including and Anastomotic is the most are linked to delayed EVT outcomes may include bowel dysfunction and to can from sponge adherence to tissue is critical to and Several key further to optimize the safety, efficacy, and accessibility of EVT for colorectal ALs. and EVT to conventional surgical are studies should both direct (eg, device and (eg, stoma in adjuvant Although EVT may the need for surgery and prolonged hospitalization, remain should also cost variability across treatment settings vs sponge exchange and device vs and studies are to validated protocols for EVT, including patient selection sponge exchange vacuum and complication these access to EVT while safety, hospital and patient of and variability in EVT including in sponge negative pressure exchange and of clinical The development of international consensus guidelines to both commercial and improvised systems improve procedural facilitate across and enhance treatment outcomes. Commercial Systems between commercial EVT kits and systems are to in clinical efficacy, and are especially in where custom may offer a alternative but lack on long-term bowel and validated outcomes after EVT remain studies are essential to the impact of the therapy on of and to potential risks of chronic dysfunction or The of EVT into enhanced after surgery protocols remains largely how EVT with such as early and reduced of may postoperative improve outcomes, and enhance and criteria on anastomotic defect size are size for EVT initiation improve patient selection, guide therapeutic and more studies should defect with treatment success, and functional outcomes. evidence-based criteria for when fecal diversion is EVT are which patients can EVT without a particularly those with contained leaks and no systemic reduce diversion and its associated morbidity, care and long-term functional outcomes. in EVT The absence of standardized remains a key to the and adoption of EVT, particularly in centers access to commercial most is on or institutional To ensure structured are These may include and multidisciplinary should emphasize endoscopic or transanal sponge vacuum system setup, pressure management, complication and optimal timing for sponge Section Summary should the and of EVT across care protocols for sponge use, pressure and are studies between commercial and custom systems can and functional outcomes and with protocols remain but are essential to ensure technical and EVT has emerged as a intervention for colorectal critical including the optimal for fecal the of management, and the influence of defect size on therapeutic of the evidence from and case in and Table 4 provides a of these which consistently support the and of EVT across clinical Given the and of an alternative and be to and and clinical These the of and long-term outcomes to and TABLE - Summary of EVT characteristics including device treatment of sponge and Device d Endo-SPONGE series 4 Endo-SPONGE Melsungen, series Endo-SPONGE series 4 Melsungen, 4 5 Melsungen, Endo-SPONGE series Endo-SPONGE 4 Endo-SPONGE 6 series Endo-SPONGE series 15 Endo-SPONGE 15 3 1 15 Endo-SPONGE 15 3 Endo-SPONGE 1 Endo-SPONGE 2 series Endo-SPONGE series Endo-VAC 4 are 5 with of that include studies but in their and to these not in the their and into the = not or not diversion remains EVT to reduce contamination and support that in particularly those with leaks and no systemic signs of diversion may not be diversion in such cases reduce morbidity and improve of EVT has been confined to settings of device and complication However, evidence that EVT, when with endoscopic and multidisciplinary oversight, is both and This may reduce hospital without compromising outcomes. The of leak size remains Although contained may to EVT or more complex leaks require procedures or The absence of standardized criteria for defect size risk studies by anatomical and clinical are to patient Despite from are EVT to surgical or alternative endoscopic have to be long-term functional outcomes such as of and the burden of remain the need for Given the risk of long-term including anastomotic bowel and is be functional and the potential for additional or permanent stoma EVT a promising or strategy in the management of colorectal optimal into evidence-based care pathways will depend on that long-term outcomes, and standardized application in clinical EVT is a promising intervention for colorectal ALs, by evidence but limited by a lack of and Key include criteria for fecal and the of defect size in Clinical and standardized protocols are essential to guide and optimize patient functional outcomes remain the need for structured and The of EVT into colorectal surgery on and

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