First, pharyngoscopy/laryngoscopy again and confirmation of the extent. The tumor is located in the base of the tongue on the left, reaching at least to the midline. The tumor extends to the glossotonsillar groove or the tonsil. This confirms the indication for surgery with flap coverage. First PEG placement: insertion of the flexible esophagoscope into the stomach. There, after creating the diaphanoscopy, insertion of a 15 mm stomach wall tube without complications. Sterile dressing. Subsequent repositioning for tumor resection and flap covering: First skin disinfection and injection of a total of 15 ml Ultracaine with adrenaline into the area of the planned apron flap and sterile covering of all surgical areas. Start with dissection of the apron flap: This is performed via the typical skin incision and by elevating the tissue subplatysmal to the level of the hyoid bone or submandibular gland. Subsequent neck dissection on the left: Exposure of the sternocleidomastoid muscle, digastric muscle and omohyoid muscle. Exposure of the infrahyoid muscles. Depiction of the common, internal and external carotid artery, internal jugular vein and facial vein. An external jugular vein is only very thin and is coagulated. The auricular nerve is exposed and preserved. Exposure of the hypoglossal nerve, vagus nerve, cervical nerve and accessorius nerve. Clearing level II to V a, with preservation of the cervical plexus. Subsequent combined tumor resection: start transorally. Tumor is palpated. Cut around the tumor with a distance of at least 1.5 cm on all sides. Resection extends beyond the midline. Resection includes the floor of the mouth, the lingual nerve is initially exposed, but must be resected later due to its proximity to the tumor. Mucosa is resected up to the alveolar ridge along the glossoalveolar groove. Lower parts of the tonsil are resected together with parts of the caudal palatal arch. Counter-operation from the transcervical side to resect the tumor in the base of the tongue while sparing the lingualis on the opposite side. Resection is performed with exposure of the lingual artery on the right side. Resection is performed in the vallecula to the left, taking the mucosa of the lingual epiglottis with it. Resection extends to the piriform sinus entrance. Cranially again up to the lower part of the palatal arch. The specimen is removed and thread-marked. An additional marginal sample is taken from the glossotonsillar groove from the floor of the mouth to the alveolar ridge to the lower edge of the tonsil. This is also thread-marked for the frozen section. In the frozen section, the tumor is basically removed on all sides in healthy tissue, but slightly higher-grade, approximately medium-grade dysplasia caudally in the direction of the vallecula, higher-grade dysplasia cannot be ruled out with certainty. Therefore resection is recommended again. An approx. 1 cm wide strip is resected, including the lateral parts of the epiglottis, the entrance of the piriform sinus up to the posterior pharyngeal wall. This goes to the frozen section marked with a thread remote from the tumor. Confirmation that this marginal sample is tumor-free at the markings remote from the tumor. Thus overall R0 resection with regard to the primary. There is now a defect in the area of the vallecula and pharyngeal side wall up to the tonsil lobe as well as in the floor of the mouth and in particular in the body and base of the tongue. Radial flap is planned after measuring the required three-dimensional dimensions. Neck dissection on the right: This neck dissection is performed in the same way as on the left side. Here too, clearing of levels II to V a. Then tracheotomy: After cutting through the thyroid isthmus and supplying it with puncture ligatures, visualization of the trachea. Entry into the trachea and creation of a broadly pedicled, visor-like, modified Björk flap. This is initially epithelized caudally. Insertion of a laryngectomy tube. Now remove the radial flap from the left forearm: mark the flap in the required three-dimensional size. Maximum length 11 cm, maximum width 7 ˝ cm. First cut around the flap ulnarly and lift subfascially. Then extend the incision into the crook of the elbow. Exposure of the superficial venous system. Only obliterated residual veins are visible here, with an insignificant volume, but still connected to the deep venous system. Visualization of the vascular pedicle. This shows a larger radial vein after confluence. Now first elevation of the superficial venous system from subfascial. Dissection of the radialis flap now from the radial side and elevation from the radial side. Exposure and preservation of the lateral antebrachial cutaneous nerve. Caudal exposure of the radial artery. After clamping and sufficient waiting time, always 100% saturation. Deposition of the radial artery. The artery is treated with 4-0 Prolene stitches. Lift the radial artery flap with the pedicle subfascially along the course of the pedicle. Outgoing, smaller vessels are clipped or treated with bipolar coagulation. In the antecubital fossa, the relatively small radial artery is exposed as far as the entrance to the brachial artery. The confluence can be followed a little further into the antecubital fossa. The flap is then removed. The small, rudimentary cephalic veins are also removed and ligated proximally. The relatively thin radial artery is supplied twice using a clip. The confluent radial vein is ligated after removal. Flush the flap with heparin solution. Subsequent insertion of the flap. This is generally very difficult due to the very narrow mouth opening. The flap is successively worked into the defect with 3-0 Vicryl single button sutures according to the preforming. Difficult suturing due to the limited space available. Finally, the flap is sutured in all dimensions sufficiently. Tension-free, complete closure. The stalk is carried forward into the left side of the neck. The connecting vessels are then shown here. The superior artery and the facial vein are selected first. Conditioning of the superior thyroid artery and the radial artery. Suture with 9-0 Ethilon single-button sutures. After opening the clamp, initially very good blood flow and good venous return. Insufficient pulsation in the course, possible vascular spasm or thrombosis. Therefore opening of the superior thyroid artery. No blood flow recognizable here, even after dilatation. Either spasm or thrombosis near the outlet. Closure of the superior thyroid artery with clips, as was previously done in the distal area of this artery. Additional ligation. Subsequent exploration of the linguofacial trunk. The facial artery, which was previously preserved, is already thrombosed. Overall, the relatively poor vascular status after chemotherapy was confirmed. The lingual artery can be visualized, the ligature is removed and the artery is shortened. Afterwards, there is good blood flow from this artery. Therefore, the radial artery is now reapproximated to the lingual artery. This is done with 9-0 Ethilon single button sutures. Again, good arterial flow and also good venous return. Therefore, the veins are now conditioned. The facial vein is conditioned with confluence of the radial vein. Selection of a coupler size 2.5 and anastomosis of the veins without any problems. Good venous return. Subsequent irrigation of the entire wound area. Careful hemostasis. Successive wound closure with insertion of a flap on the left and a Redon drainage on the right and epithelialization of the tracheostoma. Suture marking in the area of the vascular pedicle for sonographic Doppler control. The flap is then checked again. This shows that there is no blood flow after the puncture. This means that there is again insufficient perfusion via the arterial vessel. The wound must therefore be reopened on the left side. Visualization of the pedicle. Here, too, there is no longer any continuous pulsation, which means that there is another thrombosis. Opening of the artery. No sufficient blood flow recognizable here, similar to the superior thyroid artery previously. Thus, again suspected thrombosis or vasospasm. Even after dilatation, there is no longer sufficient blood flow from this vessel. The flap is flushed with heparin solution until it comes out of the venous vascular system and is recognizable again. Shortening of the vessel in the area of the linguofacial trunk. Very good blood flow here again. The radial artery is dissected like a fish mouth and anastomosed again with the now significantly larger lumen using 9-0 Ethilon single button sutures. Again, after opening the clamp, good blood flow, good venous return. Now follow the perfusion for approx. 1 hour. Here finally permanent arterial pulsation, which also provides signals with the Doppler, in contrast to the previous anastomoses. Puncture of the flap shows good perfusion. This time the anastomosis appears to remain permanently open. Therefore, wound irrigation, careful hemostasis and closure, with insertion of a new flap on the left side. Suturing of the cannula. Flap check again after skin closure. Now good blood circulation. Insertion of a 7 mm tracheostomy tube. The forearm was closed with a split-thickness skin graft taken from the right thigh. A 0.7 mm thick split-thickness skin graft was first removed from the right thigh. Hydrogel or hydrocholoid dressing is then applied here. The arm is then primarily closed in the proximal area and the split skin is successively incorporated into the defect in the area of the forearm. Care is taken to protect the lateral antebrachial cutaneous nerve of the median nerve and also to protect the ulnar artery. Octenidine-Mepilex dressing is then applied. Loose compresses are placed over this and fixed in place with absorbent cotton. Application or adjustment of a Cramer splint and fixation with a bandage. Positioning of the arm. Arm always well perfused with 100% saturation until the end of the procedure. Patient goes to the intensive care unit for postoperative monitoring. Heparin perfusor 500 units/hour must be continued postoperatively. Additionally aspirin 50 mg i.v., please repeat this the next day. Flap check every ˝ hour for the first 1 to 2 days, then according to the schedule for a total of 5 days. Antibiotics given intraoperatively should be continued for 1 week with Unacid. Nutrition via the inserted PEG tube. On the 12th day, approx. gruel swallow and then, depending on the gruel swallow or swallowing function, diet build-up or initiation of swallowing rehabilitation. Overall, in the case of radiochemotherapy for rhabdomyosarcoma, difficult situation with regard to the arterial anastomosis. Overall tongue base tumor cT2 to 3, defect coverage by radial flap. Please present at the interdisciplinary tumor conference after receiving the final histology.