Aims: A previous study demonstrated that negative pressure wound therapy (NPWT) increases tissue pressure. This conflicts with the understanding that these dressings increase perfusion. This randomised case control study investigates the effects that circumferential NPWT has on perfusion in humans and how different suction pressures influence this.

Methods: Ten healthy volunteers were recruited into the study and sequentially randomised to receive suction pressures of either −400 mmHg or −125 mmHg. With both hands placed in circumferential NPWT dressings, suction was only applied to one hand. Perfusion of both hands was then analysed simultaneously using radioisotope perfusion imaging. After allowing one week for complete excretion and decay of the isotope, an identical experiment was done on the same volunteers’, this time using the contralateral hand as the test hand. A total of 20 scans were carried out. Data were analysed using the Wilcoxon and Mann-Whitney tests.

Results: In the hands that received suction pressures of −400 mmHg, there was a highly significant mean reduction in perfusion of 40% (SD 11.5%, p< 0.0005). In the hands that received suction pressures of −125 mmHg there was also a highly significant mean reduction in perfusion (mean 17%, SD 8.9%, p< 0.0005). The reduction in perfusion of the group undergoing NPWT at −400 mmHg was significantly greater than the group undergoing NPWT at −125 mmHg (p< 0.015).

Conclusion: Tissue perfusion beneath circumferential NPWT dressings is significantly reduced when suction is applied, regardless of whether suction pressures of −125 mmHg or −400 mmHg are utilised. There is a significantly greater reduction in perfusion at suction pressures of −400 mmHg, compared to −125 mmHg. This implies that circumferential NPWT should be used with extreme caution, if at all, on tissues with compromised perfusion. This finding represents a paradigm shift in our understanding of the mechanism of action of NPWT.

Condromixoid sarcoma is a rare tumor (about 2,3% of soft tissue sarcomas in one of the series published) occurring mainly in muscular part of extremities. The reconstruction after block resection of tumor lesions of dorsal column invading the thorax almost always represents a great challenge to the surgical team. The case presented reports an infrequent location of this rare tumor what highlights it in an oncologic point of view. From the surgical point of view the surgical steps of wide tumor resection are described and of the reconstruction of the dorsal column and the involved thoracicregion (adjacent to vital structures) what resulted in an asymptomatic correction.

The authors present a case of a 47 years old patient operated to a volumous dorsal condromixoid sarcoma, practically asymptomatic, with invasion and compression of the neurological space and thoracic cavity. After biopsy, a wide resection of the tumor was made, using a double surgical approach (anterior and posterior), with resection of posterior part of vertebras D6–D9 and part of the 7th, 8th and 9th costal arches. The reconstruction consisted in correction of thoracic wall with prosthesis and stabilization of column with pedicular instrumentation from D5 to D11. The post-operatory recover had no complications and in clinically the patient is asymptomatic.

Only the elevated level of suspicion conducted the realization of biopsy in an apparent innocent lesion. The Condromixoid sarcoma occurs rarely in the nervous axis, what created some difficulties in the histological diagnosis. The dimensions of the tumor mass and its localization were object of great discussion and of detailed surgical planning. After a massive surgical resection, the clinical result after 2 years of follow-up is excellent (patient asymptomatic). The almost inevitable oncological decision of surgery in a malignant tumor with medullar cord compression was the only effective way of treatment.