After appropriate preparation, first diagnostic panendoscopy. This shows the large tumor of the left piriform sinus with transition to the laryngeal skeleton and the postcricoid region. Removal of the instruments while protecting the edentulous maxilla. Followed by sterile washing and draping. First perform the tracheotomy through <CLINICIAN_NAME> and <CLINICIAN_NAME> between the 2nd and 3rd tracheal clasps. Then draw in and incise the apron flap, which is folded upwards. Careful dissection in the area of the left cervical vascular nerve sheath in the case of left carotid disobliteration. Then skeletonize the vascular nerve sheath on the right side with exposure of the hypoglossal nerve and release of the hyoid bone. Subsequent removal of the attachment of the constrictor pharyngis muscle to the lateral thyroid cartilage and extensive release of the piriform sinus on the right. Dissection of the thyroid lobe after cutting through the straight neck muscles. This mobilizes and sufficiently develops the larynx on the right side. Then transition to the opposite side. A similar procedure is performed here, whereby the common carotid artery is first accessed caudally in the area of the scar plate and dissected upwards. Here too, as on the opposite side, the superior thyroid artery can be dissected free for a possible microvascular anastomosis. Subsequent cranial placement of the hyoid bone. Dissection onto the epithelium of the epiglottis and disluxation of the epiglottis. Incision of the hypopharynx. Then the exophytically growing tumor is seen, which is successively released while leaving out the right piriform sinus. The right piriform sinus is naturally included and the two incisions are joined caudally at the cricoid plate. The larynx is then set down on the cricoid and a caudally pedicled mucosal flap is prepared for the Herrmann chimney. The larynx can now be completely removed together with the tumor. On macroscopic observation, all tumor margins are sufficiently distant from the tumor. Nevertheless, marginal incisions are made circularly from the pharyngeal defect. A questionable infiltration with a CIS is seen in the area of the upper right hypopharynx, which was furthest away from the tumor. A resection is therefore performed here. All other marginal areas are free of carcinoma and dysplasia on frozen section histology. Now insertion of a provox prosthesis in the usual manner. Myotomy of the constrictor pharyngis muscle. Subsequent closure of the pharyngeal defect, which is sufficiently wide due to the still existing right piriform sinus, with a first layer of continuous T-shaped Conley suture. The second layer contains the overlying tissue using a single-button technique. Suturing of the mucosal flap to cover the Herrmann chimney. This is followed by bilateral selective neck dissection of regions II-V while preserving all non-lymphatic structures. Insertion of a Redon drain on both sides. Folding back of the apron flap, multi-layer wound closure and completion of the mucocutaneous anastomosis in the area of the tracheostoma. Finally, sterile wound dressing and reintubation of the patient to a 3-bore cannula. End of the operation, transfer of the patient to anesthesia. Conclusion: Total laryngectomy with partial pharyngectomy on the left side for cT4 piriform sinus carcinoma. Selective neck dissection of regions II-V on both sides. Primary voice rehabilitation with a Provox Vega voice prosthesis 8 mm. Installation of a Herrmann chimney.