The current study obtained the ethical approval from the Faculty of Medicine at Medical University "Prof. Dr. Paraskev Stoyanov"—Varna, Bulgaria (Protocol 026-14/23.05.2017). Written informed consent was not needed. All procedures contributing to this work comply with the ethical standards of the relevant national (Bulgaria) and institutional guidelines on human experimentation and with the Helsinki Declaration of 1975, as revised in 2008. Our modified technique for secondary TEP is based on EENC [2]. Preoperatively a thread (e.g. 1 UPS) is mounted on the tip of a 20 CH Nelaton catheter. An opening is cut into the catheter’s wall to insert the EENC, so the tip of the catheter can be stretched on the tip of the instrument. The thread should be placed on the back side of the instrument—protected by the catheter/carrier from the scalpel (Fig. 1).

The Nelaton catheter securely loaded on the Lichtenberger endo-extralaryngeal needle carrier

Preoperatively all patients underwent lateral video fluoroscopic swallowing exam (VFSE) to check for stenosis of the neopharynx, evaluate the best potential TEP site and estimate the length of the prosthesis required.

The operation is performed under general anesthesia with intermittent apneic ventilation. Perioperatively patients were given 80 mg gentamycine i.v. as a prophylaxis of eventual infections.

We used two different approaches for introducing the needle holder. The first one involves the use of a rigid standard surgical endoscope Kleinsasser type (Fig. 2 top). Later the technique was further simplified—only an intubational laryngoscope of the Macintosh type was used (Fig. 2 bottom). With both approaches no direct visualization of the puncturing site was required or aimed, but only of the entry of the esophagus.

The intervention can be carried with both Kleinsasser type surgical laryngoscope (top) or intubational laryngoscope of the Macintosh type (bottom). The tip of the endo-extralaryngeal needle carrier is positioned by digital palpation through the stoma. The puncture is performed with scalpel blade 11

As in any TEP the keypoint here is the selection of the puncturing site. Digital palpation against the catheter/carrier tip allows evaluation of the local tissue stiffness and thickness. The endo-extralaryngeal needle holder is further slightly pushed to clearly bulge the TEP site. Upon defining the position, a 3–4 mm stab incision with a scalpel blade 11 is made in the posterior tracheal wall to the catheter tip (Fig. 3).

Intraoperative view of the bulging at the tip of the instrument. The EENC is introduced via Kleinsasser type surgical laryngoscope. The manipulations/incision are performed under intermittent apneic ventilation

Further minor dissection may be needed with a curved dissecting forceps (e.g. mosquito) till the tip of the catheter shows in the tracheal lumen. The thread is detached from the catheter and brought through the incision with gentle pull with the forceps. The EENC is removed together with the catheter. The tail of the voice prosthesis is fixed on the thread at the patient’s mouth. A gentle transstomal pull on the thread brings the prosthesis through the mouth and the neopharynx in a retrograde fashion and so it is inserted into the puncture site.

In the postoperative period patients are allowed to resume liquids and a soft diet, with advancement of diet over the next 1–3 days as tolerated by the patient. Voicing is permitted 2–3 days later.