Expert commentary: unveiling a rare adverse event

First and foremost, we congratulate Conceição et al¹ for the successful treatment of a colorectal dehiscence with a large associated infected collection using endoscopic vacuum therapy (EVT). The team worked hard to provide excellent patient care. We offer our congratulations as a recognition of your accomplishments. The reported adverse event (AE) is very rare and raises important points of discussion for those who perform EVT. This case illustrates the reason that EVT is considered a challenging technique with some associated risks that may sometimes dissuade endoscopists from using it even though it is effective and can be life-saving.

The aim of the current editorial is to discuss pivotal factors that must be understood prior to performing EVT, including some practical solutions obtained from years of experience, which may contribute to more widespread EVT adoption.

EVT has an adequate safety profile and a higher clinical success rate compared with any other endoscopic therapy for transmural GI defects.2, 3, 4, 5 It possesses a unique mechanism of action, including macrodeformation and microdeformation, changes in perfusion (stimulating angioneogenesis), exudate control, and bacterial clearance, promoting healing.^4,6 Understanding these mechanisms is imperative to avoid undesired outcomes. It is also noteworthy that inadequate drainage can significantly affect success rates and clinical outcomes.^7,8

Prior to discussing the case report, it is worth mentioning that on our review of the literature and based on personal clinical experience, luminal stenosis is not often reported as an AE of EVT.^4,5,9,10 Bleeding is also rare and usually presents as minor bleeding due to the tissue ingrowth.⁵ The other conditions outlined in the article by Conceição et al¹ such as pelvic abscesses and ileal or vaginal fistulas tend to not be AEs related to EVT but instead a consequence of unsuccessful treatment.

The authors described a colorectal anastomotic leak with an associated infected contained collection.¹ There is no question that intracavitary EVT is the best endoscopic therapy in this scenario.^8,10,11 However, the ability to achieve negative pressure is critically important. When there is a communication between the external and internal drains (both draining the same collection), the external drain must be removed or at least capped to allow the internal drain to achieve negative pressure. Maintaining the external drain in the same cavity of the EVT system may be considered for very large, infected collections as it allows for lavage when required. The external drain should not be removed, except if there is no communication with the collection.^4,12 In addition, several other factors must be discussed to minimize future EVT-related AEs.

First, in our clinical practice, patients do not need to manipulate the settings on the EVT system because we discharge the patient using the vacuum machine with pre-set settings already selected by our team. Patients are then instructed to inform our team if there is EVT system migration, bleeding, need for reservoir change (obstruction or full), or if the machine alarms. In addition, it is important to understand that the volume of fluid in the reservoir does not mean that the EVT is not working. For example, when the collection collapses around the sponge promoting granulation tissue, usually no fluid content is observed, and when the EVT system (intracavitary) migrates to the lumen, there is an increase in the reservoir volume.

Second, it is notable that the case report¹ did not mention whether the patient had a stoma. This information is crucial because when there is no stoma, enteral feeding is not recommended to reduce fecal content; parenteral nutrition is instead preferred to promote healing. Therefore, patients without a stoma should not be treated on an outpatient basis.

Third, in our practice, we do not consider 72 hours to be a delay in EVT exchange. Although EVT exchange in Europe is performed between 3 and 5 days, we routinely do it every 7 days. In general, a longer time between exchanges is associated with more tissue ingrowth and can make the procedure more challenging; however, after performing >250 of these cases at our center, we have not yet had a case in which we were unable to remove the EVT system even with 7-day exchanges.

Fourth, before surgical consideration, we believe a few different strategies could be attempted to remove the sponge in these situations such as flushing 100 mL of saline and hydrogen peroxide, pulling the EVT tube with continuous traction, performing the procedure using the underwater technique, and using a foreign body forceps. In addition, before surgery, we would recommend attempting to remove the EVT system even if aggressive traction was required as a perforation would not change the surgical indication. Nonetheless, these are challenging situations to manage.

Finally, for contained collections, the EVT system should be placed inside the collection. The incorrect position of the EVT system such as the distal end of the sponge crossing the collection wall may damage extraluminal organs, as was noted in this case report.¹ In our practice, we use the external drain to facilitate EVT placement. A .035 inch guidewire is introduced via the external drain into the collection and is then captured with the endoscope. With both guidewire tips in hand, we remove the external drain and place the EVT system. This approach allows for traction and counter-traction maneuvers, thus facilitating the procedure. This approach may reduce the risk of AEs. In addition, fluoroscopy is helpful, especially during the first few interventions.

The final appearance after successful closure proved that the authors¹ did a great job. Although there are no studies yet to support our approach, we generally perform an additional procedure after closure in an attempt to reconstruct the anatomy. In this case, endoscopic mucosal removal (simulating a septotomy) followed by anastomotic dilation with a 20 mm hydrostatic balloon would be performed.

Overall, technique standardization is needed and will likely occur as more data on EVT use are published. Patient selection is always an important consideration for optimizing patient outcomes, considering clinical status, patient preference, personal and local experience, device availability, and costs. Adjunctive therapies also need to be considered to improve efficacy and should be performed in some cases (eg, defect-associated factors such as downstream stenosis or the presence of a septum). It is also time for randomized controlled trials to better address many of these questions and provide Level 1A evidence to confirm satisfactory outcomes. As EVT use becomes more widely adopted, standardized training and credentialing processes will be required to ensure patient safety, contribute to broader reimbursement, and continue to optimize clinical outcomes.

Disclosure

The following author disclosed financial relationships: D. T. H. de Moura: Advisory Board for Bariatek Advanced Soluctions. Speaker and Proctor for Boston Scientific. Speaker and Proctor for Lynx Medical. All other authors disclosed no financial relationships.