Transferring the patient to the operating theater. Carrying out the team time-out and preliminary consultation with the anesthesia colleagues. Induction of intubation anesthesia by colleagues. Start of the operation using gastroscopy. Careful pre-scanning with gastroesophagoscope into the stomach. Air insufflation and identification of the anterior wall of the stomach. Perform positive diaphanoscopy and insertion of the PEG tube in the usual manner using the thread pull-through method without complications. Now sterile wiping and draping of the patient. Then pharyngoscopy and inspection of the oral cavity again. The exophytic tumor can be seen in the area of the floor of the mouth and the edge of the tongue. Confirmation that the midline has not been crossed and bone has not been infiltrated or reached. Therefore, confirmation of the surgical indication with flap coverage. This is followed by transoral tumor resection. The tumor is macroscopically incised with a safety margin of at least 1 cm to 1.5 cm and successively removed. The floor of the mouth with external musculature and almost the entire body of the tongue on the left side are removed. The resection extends forward to the alveolar ridge, where the mucosa is pushed away directly from the bone at the level of the alveoli and left together with the periosteum on the tumor. Overall, macroscopically, the tumor is clearly removed in healthy tissue. The tumor is marked using sutures. Send in for frozen section diagnostics. All margins tumor-free in the frozen section. Therefore R0 resection. Subsequent sterile covering of all relevant surgical areas after skin disinfection. Neck dissection on both sides and tracheostoma placement. Tracheostomy: creation of the tracheostoma approx. 0.5 cm below the cricoid cartilage, separation of the cutaneous/subcutaneous tissue. Identification of the infralaryngeal musculature and division of the musculature in the midline. After visualization of the thyroid isthmus, it is dissected after bipolar coagulation. Now locate the tracheal wall and perform the tracheotomy in the 2nd to 3rd intratracheal ring space. Epithelialization of the single button sutures, reintubation to an 8-bore tracheostomy tube. Completion of the tracheostomy without complications. Neck dissection on the right side through <CLINICIAN_NAME>: skin incision on the anterior edge of the sternocleidomastoid muscle. Cutting through the cutaneous/subcutaneous tissue. Separation of the platysma and subplatysmal flaps. Dissection. After identification of the anterior margin of the sternocleidomastoid muscle, dissection down to the deep cervical fascia. Now identify the digastric and omohyoid muscles and follow the musculature to the hyoid bone. Release the submandibular gland from the capsule. Snare the facial vein and loop upwards to protect the marginal facial ramus. Now expose the vascular cervical nerve sheath and successive removal of the neck preparation after exposing the accessorius nerve from cranial to caudal in the usual manner. All nerve branches of the cervical plexus, the accessorius nerve and the hypoglossal nerve are spared. Now perform the submandibulectomy. Dissection along the gland capsule for this purpose. Ligation of the V. facialis and the A. facialis. Identification of the mylohyoid muscle. Identification of the lingual nerve and sparing of the same. Removal of the wharton's duct and removal of the gland. Neck dissection also performed in the region of regions Ib and Ia without further complications. Primary wound closure using a platysma and cutaneous suture after placement of a 10-gauge Redon drain. Neck dissection on the left (<CLINICIAN_NAME>): Exposure of the anterior border of the sternocleidomastoid muscle, exposure of the accessorius nerve, submandibular gland, hypoglossal nerve and digaster venter anterior and venter posterior. Expose the internal jugular vein and the branches of the cervical plexus and the common carotid artery. The neck preparation is now detached from level II to V b. Punctual hemostasis. Now turn to level I b (level I a has already been removed from the opposite side by <CLINICIAN_NAME>): here the submandibular gland is dissected from the submandibular lobe. As part of the tumor resection, the lingual nerve was removed in advance so that it could no longer be exposed. However, the hypoglossal nerve was spared. The submandibular gland is finally removed after the Wharton's duct is ligated and severed using a clamp. The facial artery can be dissected and used later for the anastomosis. Level I b is now cleared out on the left under sonographic control and to ensure that all sonographically identifiable metastases have actually been removed. This is done with major problems. The tendon of the digaster muscle is now severed in the middle and the opening to the oral cavity is bluntly made using a clamp. The opening is wide enough for 3 fingers and therefore wide enough for the pedicle of the radialis flap, which has been lifted in the meantime by <CLINICIAN_NAME>. Elevation of the radial forearm flap on the left by <CLINICIAN_NAME> Palpatory identification of the distal radial artery. Marking of the flap borders (11 x 7 cm) on the distal forearm, proximal to the flexor retinaculum, with an S-shaped incision running proximally into the cubital fossa. Incision of cutaneous and subcutaneous tissue starting proximally. Identification and visualization of the venous confluence in the cubital fossa. Identification of the cephalic vein and dissection of the vein distally with integration into the radial graft margin. Identification of the ramus externus of the radial nerve and elevation of the radial portion, leaving the peritendineum of the tendons of the brachioradialis muscle intact. Subsequent ulnar incision down to the forearm fascia. Incision of the fascia and subsequent subfascial elevation of the ulnar edge of the graft up to the tendon of the flexor carpi radialis muscle. Care is taken to leave the peritendineum on the flexor tendons and to spare the ulnar artery. Identification of the distal radial artery and trial clamping with a vascular clamp. After 5 minutes with good oxygen saturation measured by pulse oximetry (measured on the index finger), the vessels are removed with subsequent ligation (Prolene 6.0). Successive detachment of the flap pedicle from the M. pronator quadratus and M. flexor pollicis longus with ligation of the outgoing perforators using a vessel clip into the cubital fossa. Exposure and protection of the radial nerve on the medial side of the brachioradialis muscle. Exposure of the brachial artery, V. mediana cubiti, A. ulnaris. First removal of the radial artery, then of two veins of the superficial venous system. Vascular ligation by means of a bypass ligature (artery) and vascular clip (veins). Subtle hemostasis in the area of the wound bed using bipolar coagulation forceps. Two-layer wound closure in the area of the proximal forearm. Defect coverage of the graft bed with split skin from the right thigh in the usual manner. Suturing of preparation swabs. Application of a wound dressing and a forearm splint. Completion of the graft lift without complications. Removal of split skin with the dermatome on the right thigh over the desired flap length. Application of a wound dressing after dermabrasion. Now suturing of the split skin in the area of the forearm in single button sutures. Primary wound closure of the proximal wound in the forearm area. Application of a forearm splint after application of the wound dressing. Now flap suturing (<CLINICIAN_NAME>, <CLINICIAN_NAME>): The flap is pulled from cervical to enoral with the clamp and can be easily adapted to the defect using 4.0 Vicryl, as previously drawn in. There is no residual defect, the flap is well adapted on all sides. Handover to <CLINICIAN_NAME> for the anastomosis of the artery. Anastomosis of the superior thyroid artery flap, venous anastomosis using 2 coupler sutures to the superior thyroid stroma. At the end, subtle hemostasis is performed using bipolar coagulation forceps. Subsequent extensive irrigation of the sides of the neck. Hemostasis. Wound closure in layers without insertion of a Redon drain on the right and 2 flaps on the left. This also included epithelialization of the tracheostoma. Subsequent completion of the procedure without complications. Patient goes to the intensive care unit for monitoring. Postoperative continuation of antibiotics with Unacid which was started intraoperatively, flap control according to the scheme for 5 days by means of clinical control and Doppler control if necessary. Feeding and PEG tube inserted for approx. 10 days, then diet build-up. Overall cT3 tongue margin/mouth floor carcinoma. cN2c status. Awaiting final histology and presentation at the interdisciplinary tumor conference.