Materials and Methods:
The Institutional Ethics Committee approved this prospective observational study on 70 patients of SBO of our institute (IRB-AIMS 2018−029). The ethical standards in the Declaration of Helsinki have been adhered to. All investigations and interventions were performed with the informed consent of the patient. The study and reporting followed the guidelines of ICMJE (International Committee of Medical Journal Editors- http://www.icmje.org) and COPE (Committee on Publication Ethics).
Inclusion criteria:
(Medical group) Patients of SBO who responded to antimicrobial therapy alone.
(Surgical group) All patients of refractory SBO who did not respond to at least four weeks of systemic antibiotic therapy and were fit to undergo surgery.
Diagnosis of SBO requires the presence of clinical features and imaging ( CECT- Contrast Enhanced Computed Tomography or MRI- Magnetic Resonance Imaging )as per Cohen and Friedman criteria.10Clinical features like pain, edema of the canal wall, ear discharge, and granulations were documented. Ear discharge and granulation tissue from the ear and nasopharynx were sent for culture and biopsy. Weekly checking of inflammatory markers [ C- Reactive Protein(CRP) and erythrocyte sedimentation rate(ESR)] was done till the patient became asymptomatic. Later, markers were checked at an interval of two weeks till they became standard value, resulting in the stoppage of antimicrobials. Antibiotics were administered through a PICC line (peripherally inserted central catheter). Relief from pain was considered an initial indicator of response to antibiotics. Patients who completed treatment with medications alone were categorized as the medical group. Those who continued to have pain despite four weeks of systemic antibiotic treatment were considered refractory and were offered surgical debridement (surgical group).
Medical group: All patients were treated with culture-directed antibiotics whenever possible. Culture included direct biopsy and culture of granulations from the ear canal and nasopharynx performed in the outpatient section. All culture-negative patients were empirically started either on intravenous (IV) Ceftazidime (2g per dose 12th hourly) or Piperacillin-Tazobactum (4.5g 8th hourly) combined with IV or oral Ciprofloxacin (IV − 400 milligrams [mg] 12th hourly, oral- 750mg 12th hourly). Antibiotics were changed after one week if the patient continued to have pain. Antifungal therapy was initiated when the patient did not respond after changing antibiotics twice or thrice. Intravenous Voriconazole at a loading dose of 6 mg/kg 12th hourly for two doses was followed by intravenous at 3 mg/kg or oral 200 mg 12th hourly as a maintenance dose.
Surgical group: Surgical option was given to patients with no pain relief after a minimum of four weeks of IV antimicrobial therapy. The surgery aimed to obtain deep tissue for culture and to reduce the microbial load as much as possible. All consenting patients underwent complete or partial debridement under general anaesthesia based on CT or MR imaging. Antimicrobials were changed if the surgery yielded culture. Otherwise, advice from the infectious diseases department was followed. The extent of debridement could be a mastoidectomy; subtotal petrosectomy with disease clearance from the tympanic ring, anterior canal wall, facial canal, jugular foramen, carotid canal, eustachian tube or petrous apex. The temporomandibular joint; parotid; parapharyngeal space, infratemporal fossa, nasopharynx, sphenoid, clivus or greater wing of the sphenoid were debrided in some cases. In some patients, only partial debridement was possible due to difficult access. Histopathology and cultures for fungus, bacteria, and acid-fast bacillus were done. In those already on multidrug therapy, a DNA-PCR with gene sequencing improved the yield.11
In both groups, treatment ended when the inflammatory markers remained normalized for six weeks in a symptom-free patient. After the initial scan, CT or MRI scans were done only for new symptoms. Radiological follow-up was with 32 FDG - PET CT (Fluorodeoxyglucose- Positron Emission Tomography) scans in all cases. Usually, it confirmed disease clearance at the end of 6 to 8 weeks of treatment if the patient was asymptomatic. If possible, the PET scan was repeated every 8 to 12 weeks when the treatment became prolonged. At the end of the study period of 26 months, there were 35 patients in the surgical group. First, 35 patients who completed medical treatment comprised the medical group. We used absent activity in PET scans as an indicator of cure in our patients.7 The rapidity of relief from pain, ear discharge, edema of the ear canal, granulations, and duration of treatment in both groups were evaluated. For the medical group, the entire duration of antimicrobial treatment was taken. For the surgical group, the duration of treatment included the initial antimicrobial therapy, the surgery, and postoperative therapy. The antimicrobial treatment before surgery ranged from 4 weeks to 36 weeks. Follow-up ranged from 12 weeks to 26 months.
Statistical analysis:
Statistical analysis was done using the IBM SPSS Statistics 20 Windows (SPSS Inc., Chicago, USA). The results are given in mean ± SD for all the continuous variables and frequency (percentage) for categorical variables. To test the normality of the data, the Kolmogorov-Smirnov test was applied. Independent sample t-test and Mann-Whitney U test were applied to compare the two groups’ mean/ average of continuous parameters. A p-value < 0.05 was considered statistically significant. All tests of statistical significance were two-tailed.