Treatment Strategies for Pilonidal Sinus Disease in Switzerland and Austria

Background and objective: No current nationwide consensus exists on pilonidal disease (PD) treatment in Switzerland and Austria. The objective of this study was to assess and compare the spectrum of PD treatment strategies in Switzerland and Austria. Materials and Methods: A survey including 196 certified institutions (Switzerland, N = 99 and Austria, N = 97) was performed. Treatment strategies for both chronic and acute pilonidal disease were investigated, as well as evolution of treatment over the last 20 years. Results: In total, 92 of 196 (47%) hospitals participated in the survey. Recurrence rate (20%) was similar between the two countries. In acute pilonidal disease, a two-stage approach with incision and drainage as the first step was preferred over a one-stage procedure in both countries. In Austria, all patients with chronic pilonidal disease were treated as inpatients, whereas 28% of patients in Switzerland were treated on an outpatient basis (p = 0.0019). Median length of hospital stay was double in Austria (four days) compared to Switzerland (two days; p < 0.001). Primary resection and off-midline closure (p = 0.017) and the use of tissue flaps (p = 0.023) were performed more commonly in Austria than in Switzerland. Minimally invasive techniques were performed more often in Switzerland than in Austria (52% vs. 4%, p < 0.001). Overall, wide excision with secondary wound healing or midline closures declined over the last 20 years. Conclusion: Treatment strategies for chronic PD differ between Austria and Switzerland with more and longer inpatient care in Austria, increasingly minimally invasive approaches in Switzerland, and outdated procedures still being performed in both countries. Overall, heterogeneity of practice dominates in both countries.

Primary or secondary wound healing of the Pin Sites After Removal of the External Fixator: Study Protocol for a Prospective, Randomized Controlled Mono-center Trial

Background: Temporary fixation with an external fixator is used for numerous indications in orthopedic trauma surgery. It is unclear whether primary wound healing or the secondary open wound healing after removal of the external fixator should be advocated for the pin site. This study compares primary wound closure with secondary wound healing for the pin sites. The primary aim is to compare the infections rates of the pin site. Secondary aim is to compare time to wound healing and esthetic outcome. The hypothesis was that primary wound closure does not lead to more infections than secondary wound healing. Methods: This is a prospective, randomized, controlled and blinded monocenter study based on a non-inferiority design. To obtain an equal patient population and groups, all pin entry sites of the patients are treated alternately at the time of removal of the external fixator with primary wound closure and secondary wound healing. Patients are randomized whether the proximal pin entry site is treated with wound closure or by secondary open wound healing, from which the further sequence develops. The pre- and postoperative protocol is standardized for all pin entry sites. A photo documentation of the pin entry sites takes place 2 and 52 weeks postoperatively during the routine clinically follow-up visits. Further controls take place after 6, 12 and 26 weeks after the removal. The primary outcome was to demonstrate the non-inferiority of primary wound closure compared to secondary wound healing in terms of postoperative wound infections according to center of disease control (CDC). The secondary outcomes are time to complete wound healing (days) and esthetical outcome (Subjective preference of patients and Vancouver scar scale). Discussion: This study aims in answering how to deal with the pin site after removal of the external fixator. To date, no routine and generally accepted protocol exists for the management of pin sites after removal of the external fixator. This prospective, randomized, blinded monocenter trial will answer if primary wound closure or secondary wound healing should be advocated after removal of the external fixator.

Primary or secondary wound healing of the Pin Sites After Removal of the External Fixator: Study Protocol for a Prospective, Randomized Controlled Mono-center Trial

Background: Temporary fixation with an external fixator is used for numerous indications in orthopedic trauma surgery. It is unclear whether primary wound healing or the secondary open wound healing after removal of the external fixator should be advocated for the pin site. This study compares primary wound closure with secondary wound healing for the pin sites. The primary aim is to compare the infections rates of the pin site. Secondary aim is to compare time to wound healing and esthetic outcome. The hypothesis was that primary wound closure does not lead to more infections than secondary wound healing. Methods: This is a prospective, randomized, controlled and blinded monocenter study based on a non-inferiority design. To obtain an equal patient population and groups, all pin entry sites of the patients are treated alternately at the time of removal of the external fixator with primary wound closure and secondary wound healing. Patients are randomized whether the proximal pin entry site is treated with wound closure or by secondary open wound healing, from which the further sequence develops. The pre- and postoperative protocol is standardized for all pin entry sites. A photo documentation of the pin entry sites takes place 2 and 52 weeks postoperatively during the routine clinically follow-up visits. Further controls take place after 6, 12 and 26 weeks after the removal. The primary outcome was to demonstrate the non-inferiority of primary wound closure compared to secondary wound healing in terms of postoperative wound infections according to center of disease control (CDC). The secondary outcomes are time to complete wound healing (days) and esthetical outcome (Subjective preference of patients and Vancouver scar scale). Discussion: This study aims in answering how to deal with the pin site after removal of the external fixator. To date, no routine and generally accepted protocol exists for the management of pin sites after removal of the external fixator. This prospective, randomized, blinded monocenter trial will answer if primary wound closure or secondary wound healing should be advocated after removal of the external fixator.

A modified scar model with controlled tension on secondary wound healing in mice

Pathological scars might cause a distorted appearance and restricted mobility, and the study of scar pathophysiology has been hindered by the absence of a reliable model. In this study, we introduce a model with a modified device to induce controlled tension on a wound healing by secondary intention to overcome the shortcomings of the model generated by Aarabi et al. We investigated and recommend an induction of 0.1 N/mm2 tension on day 7 for 14 days to mimic the characteristics of human scars. A 3.5-fold increase in scar tissue and a 2-fold increase in collagen production were induced by the modified model. Histologically, the modified method increased scar thickness. However, no significant difference was found in cell density between the two groups. This modified procedure significantly increased scar tissue, which could be used for further cellular and biomolecular research. The mechanical force applied to the wound became measurable and controllable. This method is more convenient for researchers to observe in real-time and for providing timely adjustments of the tension used in this modified model.

Primary or secondary wound healing of the Pin Sites After Removal of the External Fixator: Study Protocol for a Prospective, Randomized Controlled Mono-center Trial

Background: Temporary fixation with an external fixator is used for numerous indications in orthopedic trauma surgery. It is unclear whether primary wound healing or the secondary open wound healing after removal of the external fixator should be advocated for the pin site. This study compares primary wound closure with secondary wound healing for the pin sites. The primary aim is to compare the infections rates of the pin site. Secondary aim is to compare time to wound healing and esthetic outcome. The hypothesis was that primary wound closure does not lead to more infections than secondary wound healing. Methods: This is a prospective, randomized, controlled and blinded monocenter study based on a non-inferiority design. To obtain an equal patient population and groups, all pin entry sites of the patients are treated alternately at the time of removal of the external fixator with primary wound closure and secondary wound healing. Patients are randomized whether the proximal pin entry site is treated with wound closure or by secondary open wound healing, from which the further sequence develops. The pre- and postoperative protocol is standardized for all pin entry sites. A photo documentation of the pin entry sites takes place 2 and 52 weeks postoperatively during the routine clinically follow-up visits. Further controls take place after 6, 12 and 26 weeks after the removal. The primary outcome was to demonstrate the non-inferiority of primary wound closure compared to secondary wound healing in terms of postoperative wound infections according to center of disease control (CDC). The secondary outcomes are time to complete wound healing (days) and esthetical outcome (Subjective preference of patients and Vancouver scar scale). Discussion: This study aims in answering how to deal with the pin site after removal of the external fixator. To date, no routine and generally accepted protocol exists for the management of pin sites after removal of the external fixator. This prospective, randomized, blinded monocenter trial will answer if primary wound closure or secondary wound healing should be advocated after removal of the external fixator.