17.3. Wound Examination and Drain Monitoring
@ProfFishchenkoAfter BESS/UBE, we assess the surgical wound together with the patient's symptoms and neurological examination findings. We compare the appearance of the portals and the amount of fluid in the reservoir with the previous assessment.
1. Examination of the portals and dressing
We examine each portal incision, the surrounding skin, and the drain exit site if a drain is present. We pay attention to:
• the condition of the wound edges and any separation;
• redness, local warmth, and tenderness;
• swelling, its extent, and progression;
• dressing saturation, the nature of discharge, and how rapidly it appears.
We distinguish a small stable stain on the dressing from repeated or rapid saturation. We correlate local changes with pain intensity, body temperature, and general condition.
When changing the dressing, we use an aseptic non-touch technique: we do not touch the wound or the surfaces of materials that will contact it. NICE recommendations.
2. Assessment of discharge and drain function
If a drain has been left in place, we record the volume of discharge over a defined period, its nature, and its evolution. We separately check tube fixation, the absence of kinks, the integrity of connections, and the condition of the reservoir.
We do not equate the volume of discharge after an endoscopic procedure with blood loss: the fluid may contain residual irrigation solution and wound exudate. However, a clear appearance alone neither confirms nor excludes cerebrospinal fluid leakage.
We assess a sudden cessation of outflow in the context of the patient's condition. If it is accompanied by increasing pain or swelling, we check the system and repeat the examination.
The presence of a drain and a small discharge volume do not exclude a compressive hematoma. Postoperative hematomas with severe neurological deficits have been reported even with functioning drains. Drainage measurements therefore do not replace neurological monitoring. Chimenti and Molinari, 2013.
3. Our drain management
In our practice, after lumbar BESS/UBE decompression or discectomy, we remove the drain the day after surgery. If there are signs of drain-related irritation of neural structures, we remove it immediately, without waiting for the scheduled time.
If new radicular pain, sensory changes, or weakness develops, we immediately assess neurological status and stop suction. We consider both possible contact between the tube and neural structures and the effects of negative pressure.
After removing the drain, we reassess pain, strength, and sensation. If symptoms persist or progress, we continue evaluation to establish the cause of the new neurological deficit.
In our practice, we do not leave a wound drain after cervical BESS procedures, BELIF/UBE-LIF, or a recognized intraoperative dural injury.
The drainage technique is described in §2.11, and drain-related irritation of neural structures in §16.6.
4. Changes requiring additional assessment
Bleeding or a compressive collection. Increasing swelling, rapid saturation of the dressing with blood, or increasing bloody discharge requires examination by the surgeon. New weakness, perineal sensory disturbance, or bladder or bowel dysfunction requires urgent assessment regardless of wound appearance or drain function. Further details: §16.4 “Epidural Hematoma”.
Possible cerebrospinal fluid leakage. Persistent clear discharge, repeated wetting of the dressing, or the appearance of a fluid collection near the wound requires exclusion of a dural defect. We also ask about headache and its relationship to body position. A dural injury unrecognized during BESS may first present postoperatively as leakage through the wound. Kim et al., 2020.
In our practice, after closure of a dural defect, we monitor the wound for cerebrospinal fluid leakage during the first week. The relevant management is described in §16.5.
Possible infection. Increasing redness, local warmth and tenderness, purulent discharge, separation of wound edges, or fever requires assessment for infection. We consider an individual sign together with other local and systemic manifestations. NICE NG125.
5. Documentation and repeat examination
The record specifies:
• the examination time and condition of the portals, dressing, and surrounding tissues;
• the nature and volume of discharge, specifying the measurement period;
• the condition of the drainage system, if present;
• symptoms and associated neurological changes;
• actions taken, the time of drain removal, and the patient's condition afterward.
After drain removal, we examine the exit site, apply a dressing, and subsequently monitor for discharge or swelling. We explain to the patient which changes must be reported immediately.
In our practice, the day after surgery, we routinely perform:
• after BESS/UBE decompression or discectomy—follow-up MRI;
• after BELIF/UBE-LIF—follow-up CT.
This is routine postoperative monitoring, rather than an examination performed only when symptoms are present. We correlate the findings with the clinical presentation.
Practical principle: we assess the wound, drain function, and neurological presentation together. None of these components alone excludes a postoperative complication.
References
1. NICE. Surgical site infections: prevention and treatment. NG125. Section “Postoperative phase”. Recommendations.
2. Chimenti P., Molinari R. Post-operative spinal epidural hematoma causing American Spinal Injury Association B spinal cord injury in patients with suction wound drains. Journal of Spinal Cord Medicine. 2013;36(3):213–219. Full text.
3. Verghese N.P., Altunbi B., Ashaolu O. Suction-induced intradural nerve root kinking following lumbar decompression: A rare mechanical complication with radiographic resolution. Surgical Neurology International. 2025;16:456. Full text.
4. Kim J.E., Choi D.J., Park E.J. Risk Factors and Options of Management for an Incidental Dural Tear in Biportal Endoscopic Spine Surgery. Asian Spine Journal. 2020;14(6):790–800. Full text.
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Chapter 17. Postoperative Period
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