Prediction of tissue deformation based on mechanical and physiological factors in the prone position during surgery.

AIM: This study aimed to predict tissue deformation based on the pressure applied while lying in the prone position and physiological factors. METHODS: Healthy volunteers were instructed to lie on mattresses of four different hardness levels (50, 87.5, 175, and 262.5 N). The order in which the mattresses were used was randomized per participant. Pressure at the iliac crests was measured using a pressure mapping sensor sheet. Participants were placed in the prone position for 10 min, with pressure data used from the latter 5 min. For the tissue deformation at the iliac crests, our previous study data were used. Multiple regression analysis was used to identify predictive mechanical and physiological factors. RESULTS: The distance between the left and right greater trochanters, maximum interface pressure and age were significant predictors for compression of the skin and soft tissue. Significant predictors of internal soft tissue displacement were the distances between the left and right anterior superior iliac spines and greater trochanters. No factors predicted skin surface displacement. CONCLUSIONS: Our study provided predictive factors that may be measured easily in a clinical setting to reduce the risk of pressure ulcers during surgery in the prone position.

Investigation of effects of urethane foam mattress hardness on skin and soft tissue deformation in the prone position using magnetic resonance imaging.

AIM: In operating rooms, the occurrence of pressure ulcers caused by being in the prone position is the highest among that of pressure ulcers caused by being in other surgical positions. Thus, we investigated effects of hardness and shape of urethane foam mattresses for preventing pressure ulcers during surgery performed with patients in the prone position. We aimed to elucidate how mattresses of variable hardness and shapes affect compression and displacement of the skin and soft tissues with external force in the prone position. MATERIAL AND METHODS: We assessed effects of two shapes [rectangular cube (RC) and trapezoid cube (TC)] and four degrees of hardness (50, 87.5, 175, and 262.5 N) in each shape. We performed magnetic resonance imaging (MRI) of the iliac crests with external force while participants reclined in the prone position on eight different mattresses. RESULTS: Compression of the skin and soft tissue was significantly higher with 87.5-, 175-, and 262.5-N mattresses than that with 50-N mattresses. Skin and soft tissue displacement was higher with TC mattress than that with RC mattress, and the extent of skin surface and internal soft tissue displacement was different. CONCLUSIONS: Compression of the skin and soft tissue depends on mattress hardness; however, a threshold value (175 N) for hardness exists, above which no further changes in the parameters were observed. Skin and soft tissue displacement does not depend on mattress hardness, but rather on its shape. Furthermore, mattress inclination increases skin surface displacement.

Recurrent female adnexal tumor of probable Wolffian origin treated with debulking surgery, imatinib and paclitaxel/carboplatin combination chemotherapy: A case report.

In view of the small number of recurrent and metastatic cases of female adnexal tumors of probable Wolffian origin (FATWO), there is a distinct lack of evidence to support recommendations regarding treatment. In the present study, a 37-year-old female was diagnosed with a left adnexal tumor and underwent a left salpingo-oophorectomy (SO). The tumor was found to arise from the left tubal fimbria and extend to the posterior leaf of the broad ligament. Pathological examination identified a number of solid, tubular and cystic architectures, with areas of hyalinization, hemorrhage and necrosis. Immunohistochemistry detected that the tumor cells were positive for cytokeratin (CK)7, vimentin, inhibin and calretinin, and negative for CK20, epithelial membrane antigen, and the estrogen and progesterone receptors. Thus, the patient was diagnosed with FATWO. Following 15 months, the patient developed recurrent tumors and subsequently underwent a total abdominal hysterectomy, a right SO and extirpation of the disseminated tumors, but with incomplete debulking. The tumor cells were immunoreactive for KIT. As there are a limited number of treatment options and few reported cases, limiting the therapy recommendations, imatinib mesylate was administered for 6 months and the tumors were temporarily stabilized for 4 months until the disease progressed. The patient underwent a further debulking surgery that did not achieve complete debulking and was subsequently administered a combination chemotherapy of paclitaxel and carboplatin. This regimen resulted in an almost complete response after 10 cycles. The tumors continued to decrease in size, and the tumors in the left side of the Douglas pouch and the right para-colic gutter were no longer detectable. To the best of our knowledge, the current study is the first to report carboplatin and paclitaxel combination therapy demonstrating a response of this degree to recurrent FATWO following the failure of imatinib treatment. However, surgical debulking remains the most effective treatment for FATWO when is it is possible. The precise role of chemotherapy, radiotherapy and molecular-targeting therapy in the treatment of recurrent or metastatic FATWO remains to be elucidated, and therefore, novel strategies to overcome this disease must be prioritized.