Nanocomposite hyaluronic acid-based hydrogel for the treatment of esophageal fistulas

Fistulas are abnormal connections between two body parts that can impair the quality of life. The use of biological glues represents the least invasive procedure to fill the fistula; however, it is limited by the need of multiple injections, the persistence of infection and the failure in the treatment of high-output fistulas. We describe herein the use of an injectable nanocomposite hydrogel that is able to form in situ a tissue-mimicking matrix as an innovative material for the treatment of esophageal fistulas. Injectable hydrogels that have the dual advantage of being implantable with a minimally invasive approach and of adapting their shape to the target cavity, while the introduction of mesoporous silica nanoparticles opens the possibility of drug/biomolecules delivery.

The hydrogel is based on hyaluronic acid (HA), the crosslinking process occurs at physiological conditions leading to a hydrogel made of >96% by water and with a large-pore micro-architecture. The kinetic profile of the hydrogel formation is studied as a function of HA molecular weight and concentration with the aim of designing a material that is easily injectable with an endoscopic needle, is formed in a time compatible with the surgical procedure and has final mechanical properties suitable for cell proliferation. The in vivo experiments (porcine model) on esophageal-cutaneous fistulas, showed improved healing in the animals treated with the hydrogel compared with the control group.

Structured versus narrative reporting of pelvic MRI in perianal fistulizing disease: impact on clarity, completeness, and surgical planning

OBJECTIVE

To evaluate clarity, completeness, and impact on surgical planning of MRI reporting of perianal fistulizing disease using a structured disease-specific template versus narrative reporting for planning of disease treatment by colorectal surgeons.

MATERIALS AND METHODS

In this HIPAA-compliant, IRB-approved study with waiver of informed consent, a structured reporting template for perianal fistulizing disease MRIs was developed based on collaboration between colorectal surgeons and abdominal radiologists. The study population included 45 consecutive patients who underwent pelvic MRI for perianal fistulizing disease prior to implementation of structured reporting, and 60 consecutive patients who underwent pelvic MRI for perianal fistulizing disease after implementation of structured reporting. Objective evaluation of the reports for the presence of 12 key features was performed, as also subjective evaluation regarding the clarity and completeness of reports, and impact on surgical planning.

RESULTS

Significantly more key features were absent in narrative reports [mean: 6.3 ± 1.8 (range 3-11)] than in structured reports [mean: 0.3 ± 0.9 (range 1-5)] (p ≤ 0.001). The use of structured reporting also increased the percentage of completeness (72.5-88.3% for surgeon 1, and 61.2-81.3% for surgeon 2; p = 0.05 and 0.03, respectively), helpfulness in surgical planning (7.1 ± 1.5-7.6 ± 1.5 for surgeon 1, and 5.8 ± 1.4-7.1 ± 1.1 for surgeon 2; p = 0.05 and p < 0.001, respectively), and clarity (7.6 ± 1.3-8.3 ± 1.1 for surgeon 1, and 5.2 ± 1.4-7.1 ± 1.3 for surgeon 2; p = 0.006 and p < 0.001, respectively) of the reports.

CONCLUSION

Structured MRI reports in patients with perianal fistulizing disease miss fewer key features than narrative reports. Moreover, structured reports were described as more complete and clear, and more helpful for treatment planning.

Permacol™ collagen paste injection for the treatment of complex anal fistula: 1-year follow-up

BACKGROUND

Optimal surgical treatment for anal fistula should result in healing of the fistula track and preserve anal continence. The aim of this study was to evaluate Permacol™ collagen paste (Covidien plc, Gosport, Hampshire, UK) injection for the treatment of complex anal fistulas, reporting feasibility, safety, outcome and functional results.

METHODS

Between May 2013 and December 2014, 21 consecutive patients underwent Permacol paste injection for complex anal fistula at our institutions. All patients underwent fistulectomy and seton placement 6-8 weeks before Permacol™ paste injection. Follow-up duration was 12 months.

RESULTS

Eighteen patients (85.7%) had a high transsphincteric anal fistula, and three female patients (14.3%) had an anterior transsphincteric fistula. Fistulas were recurrent in three patients (14.3%). Seven patients (33%) had a fistula with multiple tracts. After a follow-up of 12 months, ten patients were considered healed (overall success rate 47.6%). The mean preoperative FISI score was 0.33 ± 0.57 and 0.61 ± 1.02 after 12 months.

CONCLUSIONS

Permacol™ paste injection was safe and effective in some patients with complex anal fistula without compromising continence.

Minimally Invasive Transanal Repair of Rectourethral Fistulas

BACKGROUND

Rectourethral fistulas (RUFs) represent an uncommon complication of pelvic surgery, especially radical prostatectomy. To date there is no standardised treatment for managing RUFs. This represents a challenge for surgeons, mainly because of the potential recurrence risk.

OBJECTIVE

To describe our minimally invasive transanal repair (MITAR) of RUFs and to assess its safety and outcomes.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively evaluated 12 patients who underwent MITAR of RUF at our centre from October 2008 to December 2014. Exclusion criteria were a fistula diameter greater than 1.5cm, sepsis, and/or faecaluria.

SURGICAL PROCEDURE

After fistula identification through cystoscopy and 5F-catheter positioning within the fistula, MITAR is performed using laparoscopic instruments introduced through Parks' anal retractor. The fibrotic margins of the fistula are carefully dissected by a lozenge incision of the rectal wall, parallel to the rectal axis. Under the healthy flap of the rectal wall the urothelium is located and the fistulous tract is sutured with interrupted stitches. After a leakage test of the bladder, the rectal wall is sutured with interrupted stitches. Electrocoagulation is never used during this procedure.

MEASUREMENTS

Fistula closure, postoperative complications, and recurrence.

RESULTS AND LIMITATIONS

Median follow-up was 21 (range, 12-74) mo. Median operative time was 58 (range, 50-70) min. Median hospital stay was 1.5 (range, 1-4) d. Early surgical complications occurred in one patient (8.3%). Recurrence did not occur in any of the cases. Limitations included retrospective analysis, small case load, and lack of experience with radiation-induced fustulas.

CONCLUSIONS

MITAR is a safe, effective, and reproducible procedure. Its advantages are low morbidity and quick recovery, and no need for a colostomy.

PATIENT SUMMARY

We studied the treatment of rectourethral fistulas. Our technique, transanally performed using laparoscopic instruments, was found to be safe, feasible, and effective, with limited risk of complications.