Laser patch welding: experimental study for application to endoscopic closure of bronchopleural fistula, a preliminary report

Endoscopic treatment of congenital H-Type and recurrent tracheoesophageal fistula with electrocautery and histoacryl glue

OBJECTIVE

Congenital H-Type tracheoesophageal fistulae (H-Type TEF) and recurrent fistulae after primary repair of esophageal atresia represent a difficult problem in diagnosis and management. The treatment traditionally involved an open technique via a cervical or thoracic route, approaches with high morbidity and mortality rates of up to 50%. Endoscopic closure of fistulae has been reported with various techniques such as tissue adhesives, electrocautery, sclerosants and laser. However, the published case series contain a small number of patients with usually short-term follow-up. The aim of this paper is to present the experience of a decade at Toronto's Hospital for Sick Children, using diathermy and histoacryl tissue adhesive and discuss the indications and limitations of this technique.

METHODS

Since 1995, 192 patients have been managed in this institution with tracheoesophageal fistulae of which 10 patients have been treated endoscopically. The fistulae were both of H-Type and recurrent tracheoesophageal fistulae following surgery for esophageal atresia and fistula division. One fistula occurred following trauma. The procedure was undertaken under general anesthesia in the image guided therapy suite under fluoroscopic control. Flexible ball electrocautery and injection of histoacryl glue were used either on their own or in combination.

RESULTS

Fistula closure was achieved in 9 out of 10 fistulae. Four patients had a second endoscopic procedure. No major respiratory or other complications were encountered in association with the procedure. Follow-up has been between 3 months and 9 years.

CONCLUSION

We conclude, endoscopic treatment of tracheoesophageal fistulae with electrocautery and histoacryl glue has been a safe and successful technique of managing H-Type and recurrent tracheoesophageal fistulae. In this paper, we discuss the indications and the surgical steps of the procedure. We highlight that diathermy should be carefully controlled and applied preferably in the small non-patulous fistulae. A fistula that has not closed after two endoscopic attempts is not suitable for further endoscopic treatment and therefore an external approach should be recommended.

Dye-enhanced protein solders and patches in laser-assisted tissue welding

OBJECTIVE

This study examines the use of dye-enhanced protein bonding agents in 805 nm diode laser-assisted tissue welding. A comparison of an albumin liquid solder and collagen solid-matrix patches used to repair arteriotomies in an in vitro porcine model is presented.

SUMMARY BACKGROUND DATA

Extrinsic bonding media in the form of solders and patches have been used to enhance the practice of laser tissue welding. Preferential absorption of the laser wavelength has been achieved by the incorporation of chromophores.

METHODS

Both the solder and the patch included indocyanine green dye (ICG) to absorb the 805 nm continuous-wave diode laser light used to perform the welds. Solder-mediated welds were divided into two groups (high power/short exposure and low power/long exposure), and the patches were divided into three thickness groups ranging from 0.1 to 1.3 mm. The power used to activate the patches was constant, but the exposure time was increased with patch thickness.

RESULTS

Burst pressure results indicated that solder-mediated and patched welds yielded similar average burst strengths in most cases, but the patches provided a higher success rate (i.e., more often exceeded 150 mmHg) and were more consistent (i.e., smaller standard deviation) than the solder. The strongest welds were obtained using 1.0-1.3 mm thick patches, while the high power/short exposure solder group was the weakest.

CONCLUSIONS

Though the solder and patches yielded similar acute weld strengths, the solid-matrix patches facilitated the welding process and provided consistently strong welds. The material properties of the extrinsic agents influenced their performance.

Successful long-term endoscopic closure of a recurrent tracheoesophageal fistula with fibrin glue in a child

We present an unusual case of recurrent tracheoesophageal fistula after primary surgical repair of congenital esophageal atresia. Traditionally, this disorder has required open-surgical correction, but successful endoscopic closure of these fistulas has been reported. This case report describes our experience using fibrin glue, applied endoscopically in a 6-year-old child, with encouraging long-term results 4 years after treatment.

Endobronchial laser therapy

We have sought to briefly outline the history and current role of laser therapy in airway obstruction. A primary goal in the use of laser therapy is the safe, effective, and rapid palliation of symptoms owing to tracheal or bronchial obstruction. This seems clearly supported in the literature despite some variation in definitions as to measurement of success. Objective criteria for improvement has also been studied, with authors noting improvement in walk tests, spirometric studies, and caliber of airways after treatment in significant percentages of patients. Patient survival, as noted by Ramser and Beamis, may not be the proper endpoint when discussing therapy, which for malignant causes, is meant to be palliative. Noting this, there are many benign conditions that may be effectively treated with laser therapy with a possible "cure" for some lesions defined as "carcinoma in situ." We believe laser therapy in the treatment of airway obstruction is an important tool that has proven beneficial in the therapy of benign and malignant lesions of the airway. Although future studies should prospectively examine survival characteristics, the current evidence firmly supports the use of laser as a useful modality of therapy in our endeavors to provide palliative and potentially curative care to our patients with lung disease.