Comparison of Loop Drainage Versus Incision and Drainage for Abscesses in Children
Condition: Abscess of Skin and/or Subcutaneous Tissue
MeSH terms: Abscess
Study type: Interventional

Summary: 
      The purpose of this study is to compare abscess drainage utilizing the vessel loop technique
      in children to the standard incision and drainage technique with the endpoint to determine if
      rates of treatment failure are non-inferior.
    

Detailed description: 
      BACKGROUND INFORMATION:

      Infections of skin and soft tissue remain one of the more common chief complaints in the
      pediatric emergency department. With methicillin-resistant Staphylococcus aureus being a
      prevalent pathogen, abscess development is not uncommon. The emergency department remains the
      common setting for required therapeutic intervention. However, active investigation exists in
      regard to the ideal intervention for children and adults.

      Incision and drainage of cutaneous abscess has remained the standard of care for years.
      However this standard has been adopted without robust supportive evidence. Recently, various
      studies have questioned the benefit of various aspects of treatment, including antibiotics,
      incision size, and necessity for packing. Other studies have even suggested a less-invasive
      approach. Some of these have utilized a vessel loop and have demonstrated a reduced need for
      home-health visits, reduced inpatient length of stay, good patient tolerance, and no increase
      in failure rates. These studies are, however, retrospective in design with execution
      primarily by the surgical team.

      STUDY DESCRIPTION:

      Upon obtaining written informed consent/assent by the study team member, subjects will be
      randomized using a computerized randomization procedure and opaque envelopes. Initially,
      thorough history and physical exam will be performed. A data sheet will be completed
      detailing patient characteristics (eg. age, gender, ethnicity, prior treatment) and wound
      characteristics (eg. greatest diameter of both erythema and induration, presence of
      spontaneous drainage, location). Pain control/procedural sedation will be selected at the
      discretion of the treating physician, consistent with current local practice (eg. topical
      lidocaine, intranasal fentanyl and/or midazolam, oral acetaminophen/hydrocodone or ibuprofen,
      intravenous ketamine, morphine, or fentanyl). Pain will be assessed prior to physical exam
      and again shortly after the procedure via the validated FACES-Revised Pain Scale. The patient
      will provide this assessment if 5 years or older. Otherwise, the parent will provide the
      degree of pain perceived for their child. The difference between these two pain assessments
      will be evaluated as an endpoint. Physicians will report on their satisfaction with the
      procedure using a 5-point Likert scale.

      The control arm of incision and drainage will require a single linear incision over the most
      fluctuant portion of the abscess at a length deemed necessary by the treating physician.
      Expressed contents will be sent for wound culture. Loculations will be disrupted with a
      hemostat followed by copious irrigation with sterile saline. At the discretion of the
      treating physician, the wound may be packed with ¼-inch iodoform gauze and dressed with dry
      gauze.

      The intervention arm of vessel loop-drainage will require placement of a small incision of
      4-5 mm at the periphery of induration. Expressed contents will be sent for wound culture.
      Using a hemostat, the loculations will be disrupted and expressed. Using the hemostat through
      the abscess cavity, the opposite aspect will be probed and a second 4-5 mm incision will be
      placed. The cavity will then be copiously irrigated with saline. A vessel loop (DeRoyal
      Industries; Powell, TN) will then be pulled through the cavity via the two incisions and
      loosely tied to itself above the skin using a surgeons knot. The wound will be dressed with
      dry gauze.

      A prescription for antibiotics and pain medication will be provided at the discretion of the
      treating physician. The parent will be given standardized wound-care instructions
      (twice-daily soaks for 5 days with dry dressing re-application), contact information (phone
      and email) will be confirmed, selection of 24-48 hour follow-up will be made, and necessity
      of the 14- and 90-day follow-up will be emphasized. The parents will be encouraged to keep a
      pain medication diary (charted upon their care instructions) and bring the diary to their 2
      initial follow-up appointments.

      Upon completion of the initial ED encounter, data will be collected regarding type of pain
      control/procedural sedation during the ED course, selection of prescribed antibiotics and
      pain medication, and eventually results of wound culture.

      24-48 hours after the incision and drainage procedure, subjects will return to the ED for a
      repeat evaluation. Packing will be removed from patients in the standard incision and
      drainage arm. The wound will be evaluated for five inflammatory components (i.e. presence of
      induration, fluctuance, drainage, tenderness, and warmth). If the evaluating physician
      decides that an abscess is still present and requires re-instrumentation, or if the infection
      requires admission for IV antibiotics, treatment failure will be declared. Following the
      assessment, the control arm may be repacked only if determined to be necessary. Parents will
      report on their satisfaction with the procedure, and simplicity of and anxiety with wound
      care utilizing a Likert scale of 1-5. Pain medication use will be quantified using their
      diary and then documented. Their contact information will be reconfirmed and the second
      follow-up appointment will be scheduled.

      Subjects in the loop-drainage arm will receive emphasized instruction about technique and
      timing of loop removal. This will be performed at home only after drainage has ceased. Local
      practice by the general surgeon group suggests this is typically around post-operative day 5.
      Previous loop studies have performed this removal near day 8 to 10. We will encourage the
      parent to remove the loop on day 7 (if drainage has ceased) by simply cutting one side of the
      loop and pulling it from the cavity. A phone call will be performed on day 7 to assess
      readiness and provide support for removal. The day of loop removal will be documented.

      Follow-up at post-procedure day 14 will be performed in the ED by a physician member of the
      study team. Prior to this visit, the parent will be reminded via telephone and email 2-3 days
      prior to the appointment. The wound will be evaluated for the same signs of inflammation as
      the previous visit. The wound will again be evaluated for indications of re-instrumentation
      or hospital admission (treatment failure). If the patient demonstrates systemic illness,
      parenteral antibiotics will be initiated with admission to the hospital. A second assessment
      will be performed at this follow-up visit; the Hollander scale will be applied to determine
      cosmetic outcome. The same Likert scales will be given to the parent regarding both the
      simplicity of, and anxiety with wound care. Pain medication use will again be quantified
      using their diary and then documented. The parent will be asked if any other physician
      encounters (here or elsewhere) were pursued and if re-instrumentation or hospital admission
      occurred. Follow-up will be encouraged with a $25 gift card (utilizing funding received from
      Scientific, Education and Research Foundation of UTSW Austin Research/Fellow Grant, and from
      research funds of the PEM fellowship department) to compensate families for their time and
      travel.

      If the subject is unable to make the second follow-up appointment, a phone call will be
      performed to inquire if the patient presented to a hospital for intervention secondary to
      treatment failure of the initial abscess. If phone follow-up is unsuccessful, computerized
      chart review of the Seton network will be performed to obtain the same end-point.

      At 3 months, parents will be called to inquire of their satisfaction with the wound scar
      using a 5-point Likert scale. They will also be reminded to return to the hospital to obtain
      photographic documentation of the scar. Another $25 gift card will be issued to those able to
      do so.

      All patient records will be maintained in a locked, secure location, accessible by research
      personnel only.
    

Intervention name(s): Vessel Loop Drainage; Incision and Drainage
Intervention type(s): Procedure; Procedure
Intervention description(s): Minimally invasive approach will utilize a vesi-loop device for the vessel loop drainage technique by placing 2 peripheral stab incisions into the abscess with a tunnel through the abscess cavity, and loop passed through the tunnel and tied atop the skin.; Standard of care treatment will utilize incision and drainage over the center of the abscess cavity with or without packing at physicians discretion.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment