Hematopoietic Stem Cell Therapy in Chronic Wounds Using a Pressure Sore Model

Aim of the study: Evaluation of feasibility, safety and potential effects of stem cells on chronic wounds using a pressure sore model. Clinical relevance: * Accelerated healing of uncomplicated wounds * Enhanced healing of complicated (chronic, non-healing) wounds Study design: * Prospective controlled phase I/II study * Cohort of 5 patients in pilot study, then reevaluation Patients: \- Para- and tetraplegic patients with sacral pressure sores grade III-IVA according to the classification of Daniel and Seiler Methods: 1\. First surgical intervention: * Radical debridement of pressure sore * Bone marrow harvest from the iliac crest * Isolation of hematopoietic stem cells, aiming to gain \> 1 mio. CD 34+ cells per patient under GMP conditions 3\. Stem cell therapy (after 2 days) * Injection of stem cells in suspension (50'000 CD 34+ cells in 100 microliter saline per cm2 of wound surface) on one half of the total wound surface and cell-free saline on the other half as a control 4\. Second surgical intervention (after 3-4 weeks): * Complete excision of the wound * Closure of the defect by fasciocutaneous flap 5\. Evaluation of wound healing: * Clinical * 3D laser imaging * Histology * Growth factor assay