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.

Osteosarcoma is the most common tumor among the primitive malignant bone tumors. When different features of these lesions are considered, we can find several varieties of this tumor, with distinct anatomo-clinical presentation, treatment and prognosis.

Until the 70s, its prognosis was very poor, the standard surgical treatment was amputation and 80% of the patients died from metastatic disease. With the development of new surgical techniques, the advent of combined chemotherapy and more accurate imaging, the outcome of these patients has improved significantly. Consequently, approximately 90% of the surgical cases are treated with limb salvage procedures.

The authors reviewed 22 cases of Osteosarcoma treated in HGSA, 20 being submitted to the T20 Rosen protocol.

Trocar biopsy was performed in 19 of the patients and 3 of the patients were submitted to incisional biopsy in order to complete diagnosis.

Regarding the anatomo-clinical pattern, Classic Osteosarcoma was present in 19 patients, 2 of the cases were Parosteal and 1 was Central low-grade Osteosarcoma.

The majority of patients underwent limb salvage surgery; only 2 had amputation surgery and 1 patient was submitted to palliative chemotherapy. Considering limb salvage procedures, several techniques were performed: arthrodesis (n=1), grafts (n=4), prosthesis (n=13) and compound prosthesis (n=1). The resection margins were wide in 19 cases, marginal in 2 cases and in 1 case intra-luminal.

Among the treated patients: 12 patients are still alive and cured, 3 have metastatic disease, 6 are deceased and 1 didn’t complete the follow-up.

The final functional score obtained was 84% for the superior limb (DASH) and 81% for the inferior limb (TESS).

Although the scarce number of cases described were not enough to make any kind of correlation, it was possible to establish the accuracy of the multidisciplinary approach involved both in the diagnosis and treatment, in agreement with the “state of art”.