Tailored Negative Pressure Wound Therapy with instillation in diabetic, hypertensive, and obese patients-when guideline treatment is not enough: a case series and a proposal for the ANSWER score.

backgroundWound healing is challenging in cases of impaired microcirculation, leading to wound chronicity, decreased quality of life, and increased morbidity. Surgical site infections (SSIs) pose a significant challenge in diabetic, hypertensive, and obese patients due to impaired microcirculation. Negative pressure wound therapy (NPWT) is a widely used adjunct in wound management, but its optimal parameters in this subgroup remain uncertain. Tailored management is essential, taking into consideration tissue perfusion status and the potential benefit of novel strategies for tissue healing.

methodsWe report a case seires of three obese patients with diabetes mellitus type 2 and arterial hypertension who developed severe SSIs after abdominal surgery, with extended flap mobilization and were managed with tailored NPWT strategies, including lower negative pressures, NPWT with instillation and dwell time (NPWTi-d), reticulated open cell foam dressings with through holes (ROCF-CC), and ultrasonic-assisted wound debridement (UAW). Based on these cases, we propose the ANSWER score (tAilored Negative presSure Wound thErapy in micRoangiopathy) to optimize NPWT pressure settings.

resultsIn Patient 1, NPWT using silver dressings was initiated at a continuous pressure of -125 mmHg, but after extended necrosis developed, the negative pressure was reduced to -50 mmHg. In Patients 2 and 3, a continuous NPWT was set at -50 mmHg, which is the lower value of the available negative pressure range for the system used, resulting in significantly fewer necrotic areas. Dressings were changed every 48–72 h and culture-directed antibiotics were administered to all patients. Our findings suggest that the use of NPWT remains a basic element in promoting acute and chronic wound healing. Innovative techniques such as NPWTi-d, ROCF-CC, and UAW debridement, combined with low negative pressure levels, may achieve optimal results in patients with microangiopathy. Microcirculation plays a crucial role in wound healing, since impaired healing and a low rate of tissue regeneration have been observed in patients with compromised tissue perfusion, such as patients with diabetes, obesity, or arterial hypertension. However, the use of NPWT in patients with microangiopathy and extensive tissue dissection at the default operating pressure of -125 mmHg may lead to further ischemic necrosis. Based on our case series, a clinical score (ANSWER score- tAilored Negative presSure Wound thErapy in micRoangiopathy) is proposed as a useful tool that reflects the ideal level of negative pressure for patients with impaired microcirculation. The ANSWER score assigns risk factors (obesity, arterial hypertension, diabetes) a point each, reducing NPWT pressure accordingly (-25 mmHg per point from − 125 mmHg).

conclusionsTailored NPWT settings, based on the ANSWER score, may enhance wound healing outcomes in patients with microangiopathy. Further clinical studies are warranted to validate this approach.