Peripheral nerve regeneration following scaffold-free conduit transplant of autologous dermal fibroblasts: a non-randomised safety and feasibility trial.

BACKGROUND: The use of Bio 3D nerve conduits is a promising approach for peripheral nerve reconstruction. This study aimed to assess their safety in three patients with peripheral nerve defects in their hands. METHODS: We describe a single institution, non-blinded, non-randomised control trial conducted at Kyoto University Hospital. Eligibility criteria included severed peripheral nerve injuries or a defect in the region distal to the wrist joint not caused by a congenital anomaly; a defect with a length of ≤20 mm in a nerve with a diameter ≤2 mm; failed results of sensory functional tests; ability to register in the protocol within 6 months from the day of injury; refusal of artificial nerve or autologous nerve transplantation; age 20-60 years; and willingness to participate and provide informed written consent. Six weeks before transplantation, skin was harvested, dermal fibroblasts were isolated and expanded, and Bio 3D nerve conduits were created using a Bio 3D printer. Bio 3D nerve conduits were transplanted into the patients' nerve defects. The safety of Bio 3D nerve conduits in patients with a peripheral nerve injury in the distal part of the wrist joint were assessed over a 48-week period after transplantation. RESULTS: No adverse events related to the use of Bio 3D nerve conduits were observed in any patient, and all three patients completed the trial. CONCLUSIONS: Bio 3D nerve conduits were successfully used for clinical nerve reconstruction without adverse events and are a possible treatment option for peripheral nerve injuries.

Physical injuries often result in damage to nerves, for example, in the hands. Replacement of the nerve with nerves removed from elsewhere in the patient's body is often the suggested treatment when the nerve is unable to repair itself. As an alternative to remove healthy nerve from elsewhere in the body, we used an adapted printer to create an artificial nerve equivalent from skin cells obtained from the patient's skin. We reconstructed the nerves of three individual with nerve defects in their hands, and we found that the function of the nerve improved, and the people did not experience negative consequences. This approach could be used widely to repair damaged nerves.

[A case of lung cancer showing a bronchial cast shadow caused by impaction of the squamous cell carcinoma itself].

A 69-year-old man presented with bloody sputum. Chest X-ray showed a trabecular shadow in the right upper lung field. Chest CT showed a bronchial cast shadow in the right B3a, extending along the bronchial bifurcations to the periphery. Impaction of the bronchus was suspected. Sputum cytology was class IIIb. Though bronchoscopic examination did not reveal a tumor or obstruction at the orifice of the right B3a, squamous cell carcinoma was diagnosed by biopsy. Right upper lobectomy was performed. Pathologically, the tumor was diagnosed as moderately differentiated squamous cell carcinoma, measuring 25 x 20 x 10mm in size. The tumor showed intrabronchial branching growth into the peripheral site of the right B3a and neither mucoid nor inflammatory granulation tissue was present. Impaction of the bronchus was made up by the squamous cell carcinoma itself. Lung cancer originating in subsegmental or sub-subsegmental bronchi, showed bronchial cast appearance due to intrabronchial growth is very rare.

[A case of desmoid tumor involving the posterior mediastinum].

A 36-year-old woman visited our department because of back pain. Chest CT showed the 35 x 20 mm mass to be located in the left posterior mediastinum. Neurogenic tumor or pulmonary sequestration was suspected. We followed the tumor for 2 years, chest CT revealed an increase in size. En bloc resection of the tumor was performed. The tumor originated in the posterior mediastinum, protruded into the thoracic cavity and adhered to the left lower lobe and invaded the diaphragm, measuring 65 x 50 x 25 mm in size. This tumor was diagnosed pathologically as desmoid tumor which showed proliferation of spindle shape cells with collagen fibers, but with no cytologic atypia or mitotic figures were present. The tumor was alpha smooth muscle actin-positive, vimentin-positive, CD34-negative. Desmoid tumor of the posterior mediastinum is very rare. Desmoid tumors grow infiltratively and the recurrence rate after operation is high. Therefore, long-term follow up will be necessary in this case, although the patient has been well for 10 months.