A Systematic Review of Complication Management During Uniportal and Biportal Endoscopic Spine Surgery: Dural Tear and Bleeding

Abstract

Study Design

Systematic Review and Narrative Review.

Objective

To evaluate the incidence, risk factors, and management strategies for iatrogenic dural tears and to provide a narrative review of intraoperative bleeding management during uniportal and biportal endoscopic spine surgery (ESS).

Methods

A systematic literature search was conducted according to PRISMA guidelines using PubMed/MEDLINE, Embase, Cochrane Library, Scopus, and Web of Science for studies published between January 1990 and August 2025. Eligible studies included English-language clinical investigations involving degenerative spinal pathology treated with full-endoscopic or unilateral biportal endoscopic (UBE) techniques. Risk of bias was assessed using the ROBINS-E tool. Data on dural tear incidence and management were systematically synthesized, while bleeding control strategies were addressed through a structured narrative review of the technical literature.

Results

Nineteen studies including 10 578 patients were analyzed. The incidence of incidental durotomy ranged from 0.54% to 13.2%. Revision surgery was the strongest predictor of dural tears, followed by lumbar spinal stenosis and surgeon learning curve. Management strategies were stratified by defect size and containment: small tears were treated conservatively or with sealants; intermediate defects with patch techniques; and large or uncontained defects with endoscopic suturing or non-penetrating clips. The biportal approach facilitated complex dural repair. Bleeding management emphasized a prevention-first strategy focused on hemodynamic control, hydrostatic tamponade, and targeted use of radiofrequency and topical hemostatic agents.

Conclusion

Effective complication management in ESS requires adaptation to the hydrostatic environment. A stratified algorithm allows safe dural repair, while structured bleeding control is essential for maintaining visualization and surgical safety.

Introduction

Endoscopic spine surgery (ESS) has rapidly evolved into a leading minimally invasive approach for treating degenerative spinal disorders across the cervical, thoracic, and lumbar regions.^1,2 Within this field, two main techniques have emerged: full-endoscopic uniportal surgery (UESS) and unilateral biportal endoscopic surgery (UBE). ³ Uniportal surgery employs a single small incision through which both visualization and instrumentation are achieved within the same cannula, minimizing soft-tissue and bone disruption and representing the least invasive variant of decompression. In contrast, UBE utilizes two separate portals, one for viewing and another for working under continuous irrigation. This configuration allows the use of standard spine instruments, making the transition smoother for surgeons accustomed to open or microscopic techniques. ⁴ Comparative studies have shown that UBE may involve longer incisions, greater blood loss, and more postoperative drainage than uniportal surgery, reflecting slightly higher tissue disruption but yielding similar short-term outcomes. ⁵ Although they differ in technical execution, both endoscopic methods provide clear advantages over open microsurgery, including reduced blood loss, shorter hospitalization, and faster functional recovery.^6,7

While these minimally invasive techniques have transformed the treatment of degenerative spine conditions, they are not exempt from complications.^8–10 Among the most relevant are incidental dural tears (IDTs) and bleeding-related events.^11,12 An IDT, or durotomy, is the most common intraoperative complication in lumbar spine surgery, with rates in endoscopic procedures varying according to technique and patient factors. ¹³ Improper management can lead to cerebrospinal fluid (CSF) leakage, infection, headache, and in rare cases, nerve root or cauda equina entrapment. ¹⁴ The continuous saline irrigation necessary to maintain a clear endoscopic view presents a unique challenge, as it can mask small tears or tamponade minor leaks, delaying recognition. Furthermore, in the context of ESS, IDTs present a complex problem distinct from their counterparts in open, “dry” surgery. In an open procedure, a dural tear typically leads to cerebrospinal fluid (CSF) leakage and intracranial hypotension. In the “wet” environment of ESS, the continuous fluid irrigation creates a pressurized system. An unmanaged dural defect can act as a one-way valve, allowing irrigation fluid to enter the intrathecal space, which can elevate intracranial pressure and, in rare but severe cases, lead to seizures, intracranial hemorrhage, or acute neurological deficits. ¹⁵

A second major concern involves intraoperative and postoperative bleeding, which can compromise visualization, procedural safety, and recovery. Even minor venous or cancellous bone bleeding can obscure the endoscopic field and prolong operative time, requiring careful hemostasis through bipolar coagulation, hemostatic agents, or irrigation adjustments. ¹⁶ Major bleeding, though rare, may result from injury to segmental vessels, epidural veins, or arterial branches, ¹⁷ while postoperative hematomas can cause neurological decline or severe pain, occasionally necessitating reoperation. Compared to conventional open surgery, where bleeding is managed with direct pressure, packing, and suction, bleeding in ESS immediately obscures the optical cavity. Even minor arterial or venous oozing mixes with the irrigation fluid, causing light refraction and absorption that results in a “red-out,” rendering visualization impossible. This loss of visualization directly also compromises surgical safety and is a primary driver for conversion to an open procedure.^18,19

Given these technical challenges and the growing global adoption of both uniportal and biportal techniques, the primary objective of this study is to systematically review the literature on the management of intraoperative bleeding and dural tears in ESS. By synthesizing current evidence, identifying effective strategies, and analyzing reported outcomes, the present study was therefore designed with two objectives. First, we aimed to conduct a systematic review focusing exclusively on clinical studies reporting intraoperative dural tears and their management during uniportal or biportal endoscopic spine surgery for degenerative conditions. Second, we aimed to provide a structured, systematic review of intraoperative bleeding management during endoscopic spine surgery based on available cohorts and outcomes. The goal is to provide spine surgeons with practical, evidence-based guidance on preventing and managing dural tears and bleeding during endoscopic spine surgery that enhances safety, informs training programs, and guides future research.

Materials and Methods

Study Design and Registration

This systematic review was conducted and reported in strict accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The detailed study protocol was developed before registration with the International Prospective Register of Systematic Reviews (PROSPERO) to ensure methodological transparency and prevent duplication of research (Registration No. CRD420251126877). All endoscopic spinal approaches and related terms used in this review will be based on the contemporary AO Spine consensus on nomenclature in endoscopic spine surgery. ²⁰

Search Strategy

A comprehensive and systematic search of the literature was performed across 5 major electronic databases: PubMed/MEDLINE, Embase, Cochrane Library, Scopus, and Web of Science. The search strategy was designed to identify all relevant publications from January 1990 to August 2025. We utilized a combination of Medical Subject Headings (MeSH) and free-text terms related to “endoscopic spine surgery” (e.g., full-endoscopic, uniportal, biportal, UBE, percutaneous endoscopic lumbar discectomy, PELD, transforaminal endoscopic lumbar discectomy, TELD, interlaminar endoscopic lumbar discectomy, IELD), “spinal region” (e.g., lumbar spine, cervical vertebrae, thoracic vertebrae, spine/surgery), and “complications” (e.g., dural tear, durotomy, cerebrospinal fluid leak, CSF leak, bleeding, hemorrhage, vascular injury, hematoma). No date or language restrictions were initially applied. The complete search strategy for all databases, including the exact Boolean syntax and field tags, is provided in Appendix 1.

Eligibility Criteria

To ensure the high quality and relevance of the included evidence, strict inclusion and exclusion criteria were established.

Inclusion Criteria

• • Study Types: The review included clinical studies such as Randomized Controlled Trials (RCTs), prospective and retrospective cohort studies, and case series that consisted of 5 or more patients.

• • Population: Studies involving patients undergoing uniportal or biportal endoscopic spine surgery for degenerative conditions of the cervical, thoracic, or lumbar spine were eligible.

• • Topic: Articles were required to report on the management strategies for intraoperative complications, specifically bleeding or dural tears.

• • Language and Timeframe: The review was limited to articles published in the English language from 1990 onwards.

Exclusion Criteria

• • Study Types: Cadaveric studies, biomechanical analyses, animal studies, technical notes without specific clinical outcome data, editorials, letters, and single case reports (fewer than 5 patients) were excluded.

• • Underlying Pathology: Studies focusing on non-degenerative indications for surgery, such as tumors, trauma, or primary spinal infections, were excluded to maintain a homogenous study population.

• • Surgical Technique: Studies utilizing microendoscopic discectomy (MED) or other tubular retractor systems dependent on a microscope (i.e., “endoscope-assisted” but not “full-endoscopic”) were strictly excluded.

Study Selection and Data Extraction

The study selection process was performed in two phases by two independent reviewers (SS and PC). First, all retrieved records were screened for relevance, with their titles and abstracts reviewed. Second, the full texts of potentially eligible articles were retrieved and assessed against the inclusion and exclusion criteria. Any disagreements regarding study eligibility were resolved through discussion and consensus or consultation with a third senior reviewer (FVI).

A standardized data extraction form was used to collect the following variables: author, year of publication, study design, sample size, surgical technique (uniportal or biportal) reported complication (dural tear or bleeding), specific management strategy, the need of conversion to open surgery during the operation, duration of bed rest, the use of the drain, and reported clinical outcomes (e.g., resolution, sequelae, reoperation rate, neurological deficits).

Quality and Risk of Bias Assessment

The methodological quality of the included non-randomized studies was assessed by the same two independent reviewers (SS and PC) using the Risk Of Bias In Non-randomized Studies-of Exposure (ROBINS-E) tool. Discrepancies were also resolved by consensus. This instrument evaluates 7 domains of bias, including confounding, selection of participants, classification of exposures, deviations from intended interventions, missing data, measurement of outcomes, and selection of the reported result. The findings were visualized using a risk-of-bias summary graphic tool (robvis).

Rationale for Meta-Analysis and Dual Review Structure

Initially, we aimed to perform a quantitative meta-analysis of the primary outcomes. Upon data extraction, we identified substantial variations in surgical protocols and reporting standards among the included articles. To avoid potential bias and misleading conclusions derived from pooling heterogeneous data, we restricted our analysis to a systematic review and narrative synthesis. Another point to address is that during the initial piloting search, it became evident that iatrogenic durotomy and intraoperative bleeding are two distinct entities in the literature. IDTs, while relatively infrequent, are discrete events that are often reported as primary or secondary outcomes in clinical cohorts, providing possibly sufficient data for a systematic review. Conversely, intraoperative bleeding is a ubiquitous event, and its management is typically described in technical notes or as part of a surgeon’s protocol rather than as a primary outcome in a comparative study. Therefore, to provide a clinically useful document, we continued to address IDTs through a formal systematic review following the protocol mentioned above. Then, we subsequently addressed intraoperative bleeding management in a dedicated narrative review section, synthesizing expert consensus and the broader technical literature. Supplement search strategy for the narrative review section in the management of intraoperative bleeding can be found in Appendix 2.

Results

Search Results and Study Selection

The initial database search yielded 998 citations. After 85 duplicates were removed, 913 records remained for title and abstract screening. Following this screening, 885 records were excluded as they did not meet the review’s objectives (e.g., were technical notes, single case reports, or focused on different pathologies). The remaining 28 articles underwent full-text review. Of these, 8 were excluded for not meeting the strict inclusion criteria, leaving 19 studies for the final qualitative synthesis. These 19 articles served as the basis for our systematic review of dural tear management. The study selection process is detailed in the PRISMA flowchart (Figure 1). The Risk of Bias of all the included studies is demonstrated in Figure 2, while the Summary of characteristics of the included studies is shown in Table 1.

Figure 1.

PRISMA 2020 Flowchart describing the study selection process

Figure 2.

Graphic visualization of the Risk of Bias assessment (ROBINS-E) for included non-randomized studies

Table 1.

Summary of Characteristics of the Included Studies, Surgical Techniques, and Complication Management Strategies

Author (Year)	Design	N	Diagnosis	ESS system	N tear (%)	Convert to open? (n)	Technique of dural closure/management	Bed rest?	Drain?	Symptoms	Revision surgery? (n, cause)
Ahn et al (2011)	Retrospective	816	LDH	Uni	9 (1.1%)	Yes (3)	Open primary suture + sealant (cadaveric dura, fibrin glue)	NA	NA	Headache, leg pain, sensory deficit	Yes (6, delayed diagnosis)
Joswig et al (2015)	Retrospective	76	LDH	Uni	1 (1.3%)	No	None (small tear not requiring repair)	NA	No	NA	No
Sen et al (2018)	Retrospective	553	LDH, LSS	Uni	3 (0.5%)	Yes (1)	Layered repair (DuraGen + Tisseel) or conservative	6 hr	NA	NA	No
Zhou et al (2018)	Retrospective	426	LDH	Uni	4 (0.9%)	No	Not specified	NA	NA	NA	No
Kim et al (2019)	Retrospective	797	LSS, LDH	Bi	18 (2.2%)	Yes (3)	Not specified	NA	Yes	Patient dissatisfaction	Yes (3, NA)
Telfeian (2020)	Retrospective	907	LDH, LSS, Cyst	Uni	4 (0.4%)	No	Durepair/DuraGen patch or observation/pressure	24 hr	NA	Headache (2)	No
Park et al (2020)	Retrospective	643	LSS, LDH	Bi	29 (4.5%)	Yes (1)	Fibrin sealant (14), Titanium clip (2), observation (12)	24-48 hr	NA	Headache (2), sensory change (3)	Yes (1, meningocele)
Hong et al (2020)	Retrospective	165	LSS, LDH	Bi	12 (7.3%)	No	4-0 silk suture with knot pusher (2), fibrin sealant (5), rest (5)	2 Days	Yes	NA	No
Lee et al (2021)	Retrospective	53	LSS, LDH	Bi	7 (13.2%)	Yes (2)	Fibrin sealant (4), microscopic suture (2)	NA	NA	Drowsiness, CSF leak, foot drop	Yes (1, duraplasty)
Fan et al (2021)	Retrospective	738	LSS	Uni	14 (1.9%)	No	Conservative (bed rest)	Yes	NA	Delayed radicular pain (1)	No
Heo et al (2022)	Case series	5	LSS, LDH	Bi	5 (100%)	No	Non-penetrating titanium clips (Anasto-Clip) + TachoSil	3-5 Days	Yes	NA	No
Vargas et al (2023)	Retrospective	15	LDH, LSS	Uni	3 (20%)	No	Supportive care/Observation	NA	NA	Seizure, cardiac arrest, intracranial air	No
Greil et al (2023)	Retrospective	174	LSS	Uni	13 (7.5%)	No	Bimanual repair: Bent K-wire inlay (DuraGen) + fibrin glue	24 hr	No	NA	No
Kim et al (2023)	Retrospective	101	Cervical LDH/FS	Uni	4 (4.0%)	No	None (observation/Wound closure)	No	Yes	NA	No
Yu et al (2024)	Retrospective	608	LDH, LSS, DLS	Bi	24 (3.9%)	No	Primary suture (1), bed rest (23)	3-5 Days	Yes	Headache, nausea (8), Delirium (1)	No
Pruttikul et al (2024)	Retrospective	393	LDH, LSS	Uni	8 (2.0%)	No	Autologous fat graft + Gelfoam + fascial suture	1 Day	NA	Numbness (1)	No
Kim et al (2024)	Retrospective	72	Spondylolisthesis	Bi	4 (5.5%)	No	Indirect repair (gelatin sponge + Tachocomb)	2 Days	Yes	NA	No
Patel et al (2024)	Case series	5	LDH, stenosis	Uni	5 (100%)	Yes (5)	Open microscopic repair (suture/patch)	NA	NA	Radiculopathy, weakness	Yes (5, root herniation repair)
Han et al (2025)	Retrospective	326	LDH	Bi	18 (5.5%)	NA	Not specified (management noted as difficult in contralateral)	NA	NA	Paresthesia, weakness	No

Abbreviations: ESS: Endoscopic Spine Surgery; FS: foraminal stenosis; Uni: Uniportal (Full-endoscopic); Bi: Biportal (UBE/BESS); LDH: Lumbar Disc Herniation; LSS: Lumbar Spinal Stenosis; DLS: Degenerative Lumbar Spondylolisthesis; NA: Not Available/Not Specified; CSF: Cerebrospinal Fluid.

The included studies encompassed a total of 10 578 patients and were predominantly retrospective cohort studies and case series, reflecting the observational nature of complication reporting in ESS. The reported incidence of iatrogenic durotomy varied widely, from 0.54% in an extensive multi-institutional study of 553 patients ¹¹ to as high as 13.2% in a smaller series of 53 patients. ²¹ This wide variance was consistently linked to several key risk factors.

Analysis of the included cohorts identified 3 consensus risk factors. First, revision surgery was the most prominently cited risk factor for IDTs. Kim et al ²² noted a significantly higher durotomy rate (12.1%) in revision biportal endoscopic interbody fusion cases compared to 0% in primary cases. Similarly, Yu et al ²³ identified revision surgery as the strongest predictor of IDTs (OR 11.48). Second, case complexity—specifically the treatment of lumbar spinal stenosis (LSS) rather than soft disc herniation—was a significant factor. Fan et al ²⁴ noted a higher complication rate in LSS, and Yu et al ²³ also identified LSS as a risk factor (OR 2.5). Third, the surgeon’s learning curve was repeatedly mentioned. Kim et al ²⁵ found that incidences of hematoma, incomplete decompression, and dural tears were all significantly higher in the first 50 cases of their cohort. Joswig et al ²⁶ also noted that all complications in their series occurred before the surgeon had reached a steady state of 40 operations.

The clinical sequelae of IDTs in the included studies ranged from asymptomatic to severe. While some patients were asymptomatic or reported transient headaches, the most commonly reported symptom of an unrecognized tear was the delayed onset of intractable radicular pain. ²⁷ The most feared complication, highlighted in several case reports and series, was transdural nerve root herniation.^14,27 In these instances, a nerve rootlet herniates through the dural defect and becomes entrapped, leading to an acute neurological deficit. A unique and severe complication category relates to the hydrostatic pressure of the irrigation fluid. Vargas et al ²⁸ described multiple cases of severe neurological events, including seizures, subarachnoid hemorrhage, and cardiac arrest, linked to increased intracranial pressure from fluid ingress through an unidentified dural tear.

The synthesis of management strategies from the 19 included studies revealed a straightforward, stratified approach based primarily on defect size, location, and nerve root herniation.

Conservative Management and Simple Sealants

For small, pinpoint dural tears, particularly in the transforaminal approach, conservative management was common. Park et al ²⁹ reported that 12 of their 29 dural tear cases were managed successfully with 24 hours of bed rest and observation alone. Similarly, Telfeian et al ³⁰ managed dural tears with Durepair or Duragen patches, supplemented with 24 hours of bed rest, noting no subsequent CSF leaks. Zhou et al ³¹ also reported a 0.9% (4/426) dural tear rate, which was managed without significant sequelae.

Patching Techniques

For medium-sized tears, a more robust “patching” or “sandwich” technique was the most common solution. Pruttikul et al ³² described a multi-layer approach using an autologous fat graft and Gelfoam, which was successful in all 8 of their patients with 2-9 mm tears, resulting in no CSF leakage. Greil et al ³³ utilized a bimanual technique to place a dural substitute inlay graft, which was then sealed with fibrin glue.

Primary Endoscopic Repair

The ability to perform primary endoscopic repair was a significant differentiator between uniportal and biportal techniques. For large, linear tears, particularly in UBE, active repair was preferred. Heo et al ³⁴ published a technical report on the repair of dural tears in 5 UBE patients using sutureless, nonpenetrating titanium vascular clips. This method was effective and avoided the difficulty of endoscopic suturing. Park et al ²⁹ also reserved nonpenetrating clips for regular-margined tears larger than 12 mm. For large, irregular defects, primary suturing was described. Hong et al ³⁵ introduced a novel knot pusher specifically designed to facilitate watertight endoscopic suturing during UBE.

Nerve Root Herniation and Conversion to Open

A critical consensus across multiple studies was the absolute necessity of identifying and reducing any herniated nerve rootlets before any repair.^14,27 Patel et al ¹⁴ presented 5 cases of transdural rootlet herniation, emphasizing that failure to reduce the rootlet leads to permanent neurological deficits. In cases where the rootlet could not be endoscopically reduced or the dural defect was too large and complex, conversion to microscopic open surgery was the definitive management. Notably, while early papers such as Ahn et al (2011) ²⁷ reported converting all 9 of their dural tear cases to open repair, more recent studies from Park et al (2020) ²⁹ and Lee et al (2021) ²¹ reported conversion rates of only 1 out of 29 and 2 out of 7 patients, respectively, which demonstrating a clear trend toward successful endoscopic management.

Discussion

Endoscopic spine surgery (ESS) has evolved into a mature minimally invasive platform for treating degenerative spinal disorders. Among its advantages—reduced tissue disruption, diminished postoperative pain, shorter hospitalization, and faster rehabilitation—it also introduces unique intraoperative challenges, including restricted visualization, fluid dynamics, and delicate instrumentation. In this review, incidental dural tears emerged as the most frequent intraoperative complication, followed by bleeding-related events. Both remain critical determinants of intraoperative stability, postoperative recovery, and surgeon confidence during the learning and consolidation phases of endoscopic practice.

Discussion: the Dural Tears

Our systematic review identifies revision surgery as the most consistent and potent predictor of incidental durotomy in endoscopic spine surgery. This finding is robustly supported by the included cohorts, with Yu et al ²³ identifying revision status as the strongest independent predictor of dural injury and Kim et al ²² reporting a precipitous rise in tear rates in revision biportal fusion cases compared to 0% in primary surgeries. Mechanistically, this heightened risk is attributable to the formidable anatomical challenges posed by revision fields, where scar formation, distorted tissue planes, and epidural fibrosis obscure landmarks and tether the dura.

Beyond the immediate risk of entry, we propose a distinct biomechanical hypothesis to explain the sequelae observed in revision procedures. In previously operated spines, chronic fibrosis reduces the native elasticity of the peridural space, preventing the normal collapse of the fluid-filled cavity created by endoscopic irrigation. ³⁶ As a result, a persistent “dead space” may remain after surgery, creating a potential reservoir for CSF accumulation and predisposing the patient to pseudomeningocele formation ³⁷ —even in cases where intraoperative inspection reveals no visible dural injury. This pathophysiological scenario adds complexity to postoperative management, as theoretically, obliterating the dead space could reduce the risk of delayed CSF-related complications.

Traditionally, prolonged drainage or external compression has been considered as a means of flattening this residual cavity. ³⁸ However, applying negative pressure introduces its own set of risks. Excessive suction may inadvertently enlarge an unrecognized micro-tear, encourage nerve rootlet herniation through a small defect, or disrupt the fragile fibrin layer that plays a critical role in spontaneous sealing. Thus, the very tool that aims to mitigate dead space may paradoxically potentiate the complications it seeks to prevent, leaving surgeons in a difficult balance between under- and over-treatment. ³⁹

Within this context, and based on our experience, we advocate for a different strategy: prioritizing meticulous endoscopic wound closure over routine drainage. When feasible, direct dural suture remains the most definitive form of repair, but even when primary closure is technically challenging, multiple adjuncts can be systematically layered. Synthetic dural patches may reinforce fragile or irregular dural edges; careful subcutaneous closure reduces superficial dead space; and a robust skin closure—such as Donatti sutures that extend beyond the borders of the endoscopic incision—provides external support to counteract fibrosis-related cavity persistence, theoretically reducing the possibility of an external CSF leak. ¹⁴ This plane-by-plane closure philosophy aims to mechanically neutralize the dead space without relying on suction, thereby avoiding the potential adverse effects associated with drains in revision endoscopic surgery.

Ultimately, this combined biomechanical and technical perspective underscores the need for future prospective studies to define evidence-based postoperative protocols tailored to the unique challenges of revision ESS. By clarifying when drains are beneficial vs harmful, and by evaluating the effectiveness of layered closure strategies, it may be possible to establish a safer and more standardized approach for managing this particularly vulnerable population.

This systematic review also provides an updated, rigorous evaluation of IDTs’ management in the context of modern endoscopic spine surgery. By synthesizing data from 19 clinical cohorts, we confirmed that management strategies are increasingly stratified by tear severity. At the same time, surgeon experience and the specific surgical approach (uniportal vs biportal) emerge as pivotal determinants of both incidence and successful repair. The synthesized findings illustrate a distinct paradigm shift in treatment philosophy. In the nascent stages of endoscopic spine surgery (ESS), as documented by Ahn et al, ²⁷ the occurrence of an intraoperative dural tear was a primary indication for immediate conversion to open microscopic repair. This conversion was considered the safest and most widely accepted strategy at the time. It is critical to recognize that this historical reliance on conversion was primarily dictated by the predominance of the transforaminal approach during the early developmental phase of ESS. Unlike the interlaminar or biportal corridors, the transforaminal trajectory imposes severe geometric constraints and a limited working angle that render complex primary suturing technically prohibitive. Consequently, for early adopters utilizing the transforaminal route, open conversion was not merely a preference but a technical necessity. As the field has expanded to include interlaminar and biportal access, the management algorithm has bifurcated based on the surgical approach. However, concomitant with the maturation of surgeon proficiency and the refinement of endoscopic instrumentation, the threshold for attempting endoscopic repair has risen substantially. The literature now delineates a clear trajectory from simple, passive patching techniques toward active, primary repair.

This evolution is most pronounced when contrasting the two dominant endoscopic modalities. In uniportal (full-endoscopic) surgery, the coaxial, single-port design imposes geometric constraints that make primary suturing technically prohibitive for most surgeons. ³² Consequently, the management of ID in uniportal cases relies heavily on inlay or onlay patch techniques. Conversely, unilateral biportal endoscopy (UBE), characterized by independent visualization and working portals, affords the surgeon the triangulation and degrees of freedom necessary to execute complex repairs. The ability to use standard needle drivers, endoscopic knot pushers, ³⁵ and non-penetrating clips ³⁴ facilitates proper primary closure, providing a significant technical advantage of the UBE technique when managing large or complex dural defects. While a higher incidence of IDTs and bleeding events was observed in biportal cohorts, this disparity may be attributable to the broader decompressive capabilities inherent to the biportal technique. Such extensive decompressions frequently involve navigating complex anatomical variations and significant epidural adhesions. Notwithstanding these statistical differences, both modalities exhibit a comparable safety profile when executed by proficient surgeons. Consequently, technique selection should be predicated on surgeon expertise, pathology complexity, and ergonomic considerations rather than solely on complication metrics.

Our systematic review reveals that the management of incidental durotomies in ESS has evolved into a stratified algorithm dictated primarily by defect size, location, and the presence of nerve root herniation. For pinpoint lesions or micro-tears, particularly in transforaminal approaches, the literature supports a conservative strategy. Multiple included cohorts^29–31 demonstrate that simple observation or the application of dural sealants, supplemented by brief bed rest, yields excellent outcomes with negligible rates of persistent CSF leakage.

As defect size increases, the strategy shifts toward mechanical containment. For medium-sized irregularities, a ‘sandwich’ or multi-layer patching technique utilizing autologous fat or muscle grafts reinforced with fibrin sealants emerges as the standard of care. The study by Pruttikul et al ³² validate this approach, reporting high success rates without the need for direct suturing. However, for large or uncontained defects, a divergence in technique is observed. While uniportal surgeons primarily rely on inlay/onlay grafts due to working channel constraints, the biportal (UBE) platform facilitates active primary repair. The use of non-penetrating titanium clips^29,34 and specialized endoscopic suturing devices ³⁵ represents a significant advancement, allowing for watertight closure of large defects that would historically require conversion. Despite the heterogeneity of current evidence and the lack of standardized protocols, these findings suggest that when an appropriate, severity-based strategy is employed, endoscopic dural management is both safe and effective. Video 1 summarizes the management strategies in incidental durotomy cases, showing how they can be applied in monoportal endoscopic spine surgery.

Perhaps the most critical clinical imperative underscored by this review is the differentiation between a contained dural defect and an uncontained defect complicated by nerve root herniation. As highlighted by Patel et al ¹⁴ and Ahn et al, ²⁷ while a simple dural tear may result in postoperative headaches, a tear associated with an entrapped nerve root represents a devastating neurological complication. Surgeons must adopt a high index of suspicion; any new, severe, or intractable radicular pain following an ESS procedure should be presumed to be an unrecognized dural tear with rootlet entrapment until proven otherwise. Applying a simple patch or sealant over a herniated rootlet will inevitably trap the neural element, resulting in a poor functional outcome and necessitating revision surgery. Therefore, the primary objective of IDTs management extends merely beyond achieving a watertight seal; it requires a meticulous inspection of the defect to ensure that all intrathecal contents are reduced and free of entrapment prior to closure.

Compared to open or microscopic decompression, ESS minimizes soft-tissue trauma and intraoperative blood loss, yet necessitates adaptation to a distinct surgical milieu. While open procedures facilitate broad exposure and direct dural repair, the endoscopic environment constrains manipulative freedom for suturing and dural mobilization, even though it offers magnified visualization of minute defects. Consequently, the management philosophy in ESS diverges from traditional methods, prioritizing defect containment and watertight sealing over complex primary repair. Meta-analyses indicate that while open lumbar decompressions are associated with dural tear rates ranging from 3% to 13%, modern ESS series report incidences typically below 2%. This suggests that, once the learning curve is mastered, endoscopic techniques offer a safety profile comparable to or superior to that of open surgery. The concomitant reductions in systemic bleeding, postoperative pain, and hospitalization duration further validate the paradigm shift toward these tissue-sparing interventions.

The learning curve represents a pivotal determinant in the incidence of intraoperative complications in ESS, a conclusion strongly supported by the findings of this systematic review. Contemporary literature consistently corroborates a higher frequency of adverse events during the initial acquisition of skills; specifically, Kim et al ²⁵ demonstrated that incidences of dural tears, hematoma, and incomplete decompression were significantly elevated during the first 50 cases. Similarly, Joswig et al ²⁶ reported that all complications in their series occurred before the surgeon reached a steady state of 40 operations. These early failures are frequently precipitated by a temporary loss of spatial orientation, aggressive drilling near the ligamentum flavum insertion, or the mishandling of unrecognized epidural adhesions. Furthermore, novice surgeons often struggle with hydrostatic pressure management; the resulting uncontrolled venous hemorrhage can critically compromise visualization, exponentially increasing the risk of iatrogenic neural injury. Consequently, mitigating these risks requires a structured educational curriculum, including simulation-based training and mentorship, to ensure safe skill acquisition during this vulnerable early adoption phase.

From an anatomical and technical perspective, both the operated spinal level and the severity of lumbar canal stenosis may plausibly influence the risk of dural injury during endoscopic spine surgery. Differences in canal dimensions, dural compliance, and neural element mobility across lumbar levels, as well as the presence of advanced stenosis with epidural adhesions and reduced working space, could theoretically increase procedural complexity and susceptibility to dural tears or epidural bleeding. However, the available evidence does not allow these relationships to be evaluated in a dural tear–specific manner. Among the studies included in this review, stratified analyses based on surgical level were inconsistently reported, and no study provided level-wise dural tear incidence. Similarly, although one included study reported that the severity of lumbar spinal stenosis was not associated with overall complication rates, ²⁴ dural tears were analyzed only as part of composite complication outcomes rather than as an isolated endpoint. As a result, any potential association between stenosis severity, surgical level, and dural tear risk may be diluted within broader complication categories. Consequently, the current literature lacks the granularity required to support meaningful risk stratification based on these variables, underscoring the need for future studies with standardized reporting of surgical level, stenosis severity, and complication-specific outcomes.

Narrative Review: Management of Intraoperative Hemostasis

Intraoperative bleeding in endoscopic spine surgery (ESS) represents a unique functional challenge; in a fluid-filled environment, hemorrhage is not primarily a matter of hemodynamic loss but of compromised visualization. ⁴⁰ Even minor oozing from the epidural venous plexus or cancellous bone can cause a “red-out,” obscuring the surgical field and precipitating iatrogenic injury. Consequently, effective hemostasis requires a preventative paradigm that begins prior to incision. Standardized protocols emphasizing strict mean arterial pressure (MAP) control (typically <90 mmHg) and ensuring the abdomen is free from compression are vital to reduce venous engorgement. ⁴¹ Furthermore, many experts advocate adding epinephrine to the irrigation fluid to induce local vasoconstriction. ⁴² This preventative phase lays the foundation for the procedure, as maintaining a clear visual field is infinitely superior to regaining one.

When significant bleeding does occur, the surgeon’s immediate reaction determines the outcome. A common pitfall among novices is to frustrate and withdraw the endoscope elsewhere, which may decrease the hydrostatic pressure around the bleeding site and allow the epidural space to fill with blood, causing the red-out situation. The correct, albeit counterintuitive, strategy is to advance the endoscope toward the source of hemorrhage while temporarily increasing irrigation inflow. ⁴³ This creates a localized hydrostatic tamponade that clears the visual field and allows for precise identification of the bleeding point. ⁴¹ In uniportal systems, transient occlusion of the outflow port can further augment this tamponade effect, whereas in biportal (UBE) systems, the independent working portal allows dynamic regulation of outflow and inflow of irrigation fluid to balance visualization with the risk of epidural hypertension. ⁴⁴

Once the bleeding source is localized, definitive control is achieved through a hierarchy of thermal, mechanical, and chemical techniques. Radiofrequency (RF) ablation serves as the “workhorse” for soft tissue and venous hemostasis, best utilized in a pulsed fashion to minimize thermal spread to neural structures. For recalcitrant cancellous bone bleeding—common after laminectomy or facetectomy—low-speed drilling with a diamond burr provides effective sealing through frictional heat denaturation, supplemented by mechanical agents like bone wax. In scenarios of diffuse, non-point-source bleeding where thermal coagulation is impractical, flowable hemostatic matrices (e.g., gelatin-thrombin combinations) have emerged as a superior solution.^41,44 These agents conform to the irregular spinal topography, providing both a mechanical plug and a biological catalyst for clot formation, often salvaging visualization in complex revision cases. This workflow is summarized in the algorithm shown on Figure 3.

Figure 3.

Algorithm for intraoperative bleeding management in endoscopic spine surgery

Finally, the management of postoperative hematoma remains a divergent practice between endoscopic modalities. In uniportal ESS, the limited surgical corridor typically collapses post-procedure, rendering routine drainage unnecessary. ³ Conversely, biportal techniques, which involve broader muscle dissection and dead space creation, may necessitate prophylactic drainage, particularly in multilevel or revision surgeries, to mitigate the risk of paraspinal or epidural hematoma. ⁴⁵ However, the available evidence regarding drainage use remains limited and heterogeneous. Among the studies reviewed in this manuscript, one investigation compared the use of one vs two drains following multilevel biportal endoscopic decompression ⁴⁶ ; however, no study compared outcomes between drain placement and no-drain strategies. Consequently, current evidence does not support definitive recommendations regarding drain use after endoscopic spine surgery, and drainage practices appear to be technique- and surgeon-dependent rather than evidence-based.

Ultimately, the successful management of bleeding in ESS is not reliant on a single tool but on a structured workflow: preoperative optimization, intraoperative hydrostatic control, and the decisive application of multimodal hemostatic agents. Video 2 summarizes the management strategies, showing how they can be applied in monoportal endoscopic spine surgery.

To translate these management strategies into a practical clinical routine, we advocate for a standardized “safety pause” before surgical closure. This protocol begins by “drying the scope”, temporarily halting irrigation to transition from a pressurized to a neutral environment. During this phase, a Valsalva maneuver is performed to identify occult dural defects that may have been tamponaded by irrigation fluid; any detected tears are then managed according to the stratified algorithm (Figure 4). Simultaneously, the surgical field is inspected for high-risk active bleeding that could precipitate postoperative hematoma. By systematically verifying both dural integrity and hemostatic stability, the surgeon can proceed to routine closure with greater confidence in preventing delayed complications (Figure 5).

Figure 4.

Stratified management algorithm for incidental durotomy during endoscopic spine surgery

Figure 5.

Proposed intraoperative safety protocol for the prevention of delayed complications

Strengths and Novel Insights

This review offers distinct methodological and conceptual advancements over prior syntheses, such as the 2018 review by Muller et al 4 ⁴⁷ or the recent 2024 analysis by Suvithayasiri et al ¹³ While Suvithayasiri et al established a foundational management algorithm based on tear size and nerve root herniation, our review refines the evidence base by enforcing a stricter inclusion threshold of 5 or more patients. By filtering out single case reports—which often detail novel “heroic” saves that may not be reproducible—we provide a synthesis based on more robust clinical cohorts, offering a more realistic representation of standard practice and outcomes. Furthermore, our analysis extends beyond the mechanical repair of the dural defect to address the underlying pathophysiology of postoperative sequelae. We introduce the “Dead Space Hypothesis” in revision surgery, proposing a distinct mechanism where fibrosis-induced loss of epidural elasticity contributes to fluid accumulation and pseudomeningocele formation. This theoretical framework suggests that management must evolve from merely “plugging the hole” to strategically managing the post-surgical cavity. Finally, this study is the first to integrate a systematic review of iatrogenic durotomy with a dedicated narrative review of intraoperative hemostasis. By treating bleeding not merely as a nuisance but as a fundamental threat to visualization that precipitates other complications, we provide a holistic safety curriculum that addresses the two most critical intraoperative challenges in endoscopic spine surgery simultaneously.

Limitations

Despite these strengths, this review is subject to several limitations inherent to the available literature and our study design. First, the primary limitation remains the retrospective nature and moderate risk of bias observed in the majority of included studies. Although we excluded single case reports to improve validity, the lack of large-scale randomized controlled trials comparing repair techniques prevents the establishment of high-level evidence-based guidelines. Second, the hybrid design of this study, combining a systematic review of dural tears with a narrative review of bleeding, was necessary due to the lack of standardized reporting for hemostatic events, but this may introduce a greater risk of bias regarding bleeding outcomes. Third, regarding our proposed “Dead Space Hypothesis,” while grounded in biomechanical principles and clinical observation, it remains a theoretical construct that prospective hydrodynamic studies have not yet validated. Future research should prioritize prospective, comparative trials to validate specific hemostatic protocols and to empirically test whether targeted dead-space management (e.g., prolonged drainage vs compression) significantly alters the trajectory of dural healing in revision endoscopic surgery.

Conclusion

This systematic review and narrative synthesis underscore that while endoscopic spine surgery offers superior tissue preservation and recovery metrics, it necessitates a fundamental adaptation in complication management dictated by its unique hydrostatic environment. Regarding incidental durotomy, the current evidence supports a stratified treatment algorithm: conservative management and sealants are sufficient for small, contained defects, whereas large or uncontained tears increasingly warrant active primary repair. Notably, the biportal (UBE) technique offers distinct ergonomic advantages for complex dural reconstruction compared to the uniportal approach, though both modalities demonstrate a high safety profile once the learning curve is mastered. Crucially, the recognition and reduction of herniated nerve rootlets remain absolute prerequisites for successful closure, regardless of the repair technique employed.

Simultaneously, effective hemostasis in ESS must be reconceptualized not as the prevention of blood loss, but as the preservation of visualization. Our review highlights that “red-out” events are best managed through a preventive hierarchy that includes strict arterial pressure control, dynamic modulation of irrigation flow, and the decisive application of advanced hemostatic agents. Ultimately, the safety of endoscopic spine surgery is defined not by the absence of complications, but by the surgeon’s ability to promptly recognize and resolve them within the closed system. As global adoption grows, future efforts must focus on standardizing these management protocols and integrating them into simulation-based curricula to safeguard patient outcomes during the transition from open to endoscopic practice.

Supplemental Material

Video 1. Management of incidental durotomy during endoscopic spine surgery. This video demonstrates dural patch application for small, contained defects and primary endoscopic dural suture for larger tears at higher risk of cerebrospinal fluid leakage.

Video 2. Intraoperative bleeding control during endoscopic spine surgery. This video illustrates different hemostatic strategies, including bipolar coagulation, absorbable hemostatic agents for venous oozing, and diamond burr drilling for cancellous bone bleeding.

ORCID iDs

Siravich Suvithayasiri https://orcid.org/0000-0001-5597-701X

Facundo Van Isseldyk https://orcid.org/0000-0003-2236-1037

Viswanadha Arunkumar https://orcid.org/0000-0002-6322-4357

Prashanth Rao https://orcid.org/0000-0002-0145-8967

Enrico Giordan https://orcid.org/0000-0002-8863-116X

Piya Chavalparit https://orcid.org/0000-0001-8662-8824

Nelson Astur https://orcid.org/0000-0002-2608-2118

Samuel Cho https://orcid.org/0000-0001-7511-2486

Jin Sung Kim https://orcid.org/0000-0001-5086-0875