Application of a Receptor-Binding-Domain-Based Simple Immunoassay for Assessing Humoral Immunity against Emerging SARS-CoV-2 Virus Variants.

We have developed a simple, rapid, high-throughput RBD-based ELISA to assess the humoral immunity against emerging SARS-CoV-2 virus variants. The cDNAs of the His-tagged RBD proteins of the virus variants were stably engineered into HEK cells secreting the protein into the supernatant, and RBD purification was performed by Ni-chromatography and buffer exchange by membrane filtration. The simplified assay uses single dilutions of sera from finger-pricked native blood samples, purified RBD in 96-well plates, and a chromogenic dye for development. The results of this RBD-ELISA were confirmed to correlate with those of a commercial immunoassay measuring antibodies against the Wuhan strain, as well as direct virus neutralization assays assessing the cellular effects of the Wuhan and the Omicron (BA.5) variants. Here, we document the applicability of this ELISA to assess the variant-specific humoral immunity in vaccinated and convalescent patients, as well as to follow the time course of selective vaccination response. This simple and rapid assay, easily modified to detect humoral immunity against emerging SARS-CoV-2 virus variants, may help to assess the level of antiviral protection after vaccination or infection.

Biological effect and chemical monitoring of Watch List substances in European surface waters: Steroidal estrogens and diclofenac - Effect-based methods for monitoring frameworks.

Three steroidal estrogens, 17α-ethinylestradiol (EE2), 17ß-estradiol (E2), estrone (E1), and the non-steroidal anti-inflammatory drug (NSAID), diclofenac have been included in the first Watch List of the Water Framework Directive (WFD, EU Directive 2000/60/EC, EU Implementing Decision 2015/495). This triggered the need for more EU-wide surface water monitoring data on these micropollutants, before they can be considered for inclusion in the list of priority substances regularly monitored in aquatic ecosystems. The revision of the priority substance list of the WFD offers the opportunity to incorporate more holistic bioanalytical approaches, such as effect-based monitoring, alongside single substance chemical monitoring. Effect-based methods (EBMs) are able to measure total biological activities (e.g., estrogenic activity or cyxlooxygenase [COX]-inhibition) of specific group of substances (such as estrogens and NSAIDs) in the aquatic environment at low concentrations (pg/L). This makes them potential tools for a cost-effective and ecotoxicologically comprehensive water quality assessment. In parallel, the use of such methods could build a bridge from chemical status assessments towards ecological status assessments by adressing mixture effects for relevant modes of action. Our study aimed to assess the suitability of implementing EBMs in the WFD, by conducting a large-scale sampling and analysis campaign of more than 70 surface waters across Europe. This resulted in the generation of high-quality chemical and effect-based monitoring data for the selected Watch List substances. Overall, water samples contained low estrogenicity (0.01-1.3 ng E2-Equivalent/L) and a range of COX-inhibition activity similar to previously reported levels (12-1600 ng Diclofenac-Equivalent/L). Comparison between effect-based and conventional analytical chemical methods showed that the chemical analytical approach for steroidal estrogens resulted in more (76%) non-quantifiable data, i.e., concentrations were below detection limits, compared to the EBMs (28%). These results demonstrate the excellent and sensitive screening capability of EBMs.

Extraction With Sweat-Sebum Emulsion as a New Test Method for Leachables in Patch-Based Medical Devices, Illustrated by Assessment of Isobornylacrylate (IBOA) in Diabetes Products.

BACKGROUND: The increasing offering of patch-based medical devices is accompanied by growing numbers of reported adverse skin reactions. Procedures for testing leachables according to ISO 10993 may not be optimal for lipophilic substances that can be mobilized on skin by sweat and sebum. We propose an improved extraction method for targeted analysis of leachables using low volumes of a sweat-sebum emulsion. The approach is illustrated by the analysis of isobornylacrylate (IBOA), a compound found in some devices and suspected for allergenic potential. METHOD: Three patch-based products were tested: an implantable device for continuous glucose monitoring (CGM), an intermittently scanned CGM (isCGM) device, and a micro-insulin pump. Quantification of IBOA was performed by gas chromatography and allergenic potential of IBOA levels was assessed by the KeratinoSens cell assay. Different combinations were used for extraction solvent (isopropanol, 5% ethanol-water solution, and sweat-sebum emulsion), extraction volumes (complete immersion vs partial immersion in 2 mm of solvent), and extraction time (3, 5, and 14 days). RESULTS: Isobornylacrylate was only found in the isCGM device. About 20 mg/L IBOA were eluted after 3 days in isopropanol but only about 1 mg/L in ethanol-water. Sweat-sebum emulsion dissolves IBOA better and gives a more stable solution than ethanol-water. Decomposition of IBOA solutions requires adjusted extraction timing or correction of results. In the sweat-sebum extract, IBOA levels were about 20 mg/L after 3 days and about 30 mg/L after 5 days, clearly above the threshold found in the KerationSens assay for keratinocyte activation (10 mg/L). CONCLUSION: Extraction by low volumes of sweat-sebum emulsion can be a superior alternative for the targeted simulating-use assessment of leachables in patch-based medical devices.

A Novel Genetically Encoded Single Use Sensory Cellular Test System Measures Bicarbonate Concentration Changes in Living Cells.

Bicarbonate plays a central role in human physiology from cellular respiration to pH homeostasis. However, so far, the measurement of bicarbonate concentration changes in living cells has only been possible by measuring intracellular pH changes. In this article, we report the development of a genetically encoded pH-independent fluorescence-based single-use sensory cellular test system for monitoring intracellular bicarbonate concentration changes in living cells. We describe the usefulness of the developed biosensor in characterizing the bicarbonate transport activities of anionophores-small molecules capable of facilitating the membrane permeation of this anion. We also demonstrate the ability of the bicarbonate sensory cellular test system to measure intracellular bicarbonate concentration changes in response to activation and specific inhibition of wild-type human CFTR protein when co-expressed with the bicarbonate sensing and reporting units in living cells. A valuable benefit of the bicarbonate sensory cellular test system could be the screening of novel anionophore library compounds for bicarbonate transport activity with efficiencies close to the natural anion channel CFTR, which is not functional in the respiratory epithelia of cystic fibrosis patients.

Two novel real time cell-based assays quantify beta-blocker and NSAID specific effects in effluents of municipal wastewater treatment plants.

Pharmaceuticals, such as beta-blockers, nonsteroidal anti-inflammatory drugs (NSAIDs) as well as their metabolites are introduced into the water cycle via municipal wastewater treatment plant (WWTP) effluents in all industrialized countries. As the amino acid sequences of the biological target molecules of these pharmaceuticals - the beta-1 adrenergic receptor for beta-blockers and the cyclooxygenase for NSAIDs - are phylogenetically conserved among vertebrates it is reasonable that wildlife vertebrates including fish physiologically respond in a similar way to them as documented in humans. Consequently, beta-blockers and NSAIDs both exhibit their effects according to their mode of action on one hand, but on the other hand that may lead to unwanted side effects in non-target species. To determine whether residuals of beta-1 adrenergic receptor antagonists and cyclooxygenase inhibitors may pose a risk to aquatic organisms, one has to know the extent to which such organisms respond to the total of active compounds, their metabolites and transformation products with the same modes of action. To cope with this demand, two cell-based assays were developed, by which the total beta-blocker and cyclooxygenase inhibitory activity can be assessed in a given wastewater or surface water extract in real time. The measured activity is quantified as metoprolol equivalents (MetEQ) of the lead substance metoprolol in the beta-blocker assay, and diclofenac equivalents (DicEQ) in the NSAID assay. Even though MetEQs and DicEQs were found to surpass the concentration of the respective lead substances (metoprolol, diclofenac), as determined by chemical analysis by a factor of two to three, this difference was shown to be reasonably explained by the presence and action of additional active compounds with the same mode of action in the test samples. Thus, both in vitro assays were proven to integrate effectively over beta-blocker and NSAID activities in WWTP effluents in a very sensitive and extremely rapid manner.

Worldwide Testing of the eFACE Facial Nerve Clinician-Graded Scale.

BACKGROUND: The electronic, clinician-graded facial function scale (eFACE) is a potentially useful tool for assessing facial function. Beneficial features include its digital nature, use of visual analogue scales, and provision of graphic outputs and scores. The authors introduced the instrument to experienced facial nerve clinicians for feedback, and examined the effect of viewing a video tutorial on score agreement. METHODS: Videos of 30 patients with facial palsy were embedded in an Apple eFACE application. Facial nerve clinicians were invited to perform eFACE video rating and tutorial observation. Participants downloaded the application, viewed the clips, and applied the scoring. They then viewed the tutorial and rescored the clips. Analysis of mean, standard deviation, and confidence interval were performed. Values were compared before and after tutorial viewing, and against scores obtained by an experienced eFACE user. RESULTS: eFACE feedback was positive; participants reported eagerness to apply the instrument in clinical practice. Standard deviation decreased significantly in only two of the 16 categories after tutorial viewing. Subscores for static, dynamic, and synkinesis all demonstrated stable standard deviations, suggesting that the instrument is intuitive. Participants achieved posttutorial scores closer to the experienced eFACE user in 14 of 16 scores, although only a single score, nasolabial fold orientation with smiling, achieved statistically significant improvement. CONCLUSIONS: The eFACE may be a suitable, cross-platform, digital instrument for facial function assessment, and was well received by facial nerve experts. Tutorial viewing does not appear to be necessary to achieve agreement, although it does mildly improve agreement between occasional and frequent eFACE users.

Enhancement of facial nerve motoneuron regeneration through cross-face nerve grafts by adding end-to-side sensory axons.

BACKGROUND: In unilateral facial palsy, cross-face nerve grafts are used for emotional facial reanimation. Facial nerve regeneration through the grafts takes several months, and the functional results are sometimes inadequate. Chronic denervation of the cross-face nerve graft results in incomplete nerve regeneration. The authors hypothesize that donor axons from regional sensory nerves will enhance facial motoneuron regeneration, improve axon regeneration, and improve the amplitude of facial muscle movement. METHODS: In the rat model, a 30-mm nerve graft (right common peroneal nerve) was used as a cross-face nerve graft. The graft was coapted to the proximal stump of the transected right buccal branch of the facial nerve and the distal stumps of the transected left buccal and marginal mandibular branches. In one group, sensory occipital nerves were coapted end-to-side to the cross-face nerve graft. Regeneration of green fluorescent protein-positive axons was imaged in vivo in transgenic Thy1-green fluorescent protein rats, in which all neurons express green fluorescence. After 16 weeks, retrograde labeling of regenerated neurons and histomorphometric analysis of myelinated axons was performed. Functional outcomes were assessed with video analysis of whisker motion. RESULTS: "Pathway protection" with sensory axons significantly enhanced motoneuron regeneration, as assessed by retrograde labeling, in vivo fluorescence imaging, and histomorphometry, and significantly improved whisker motion during video analysis. CONCLUSION: Sensory pathway protection of cross-face nerve grafts counteracts chronic denervation in nerve grafts and improves regeneration and functional outcomes.

Macroscopic in vivo imaging of facial nerve regeneration in Thy1-GFP rats.

IMPORTANCE: Facial nerve injury leads to severe functional and aesthetic deficits. The transgenic Thy1-GFP rat is a new model for facial nerve injury and reconstruction research that will help improve clinical outcomes through translational facial nerve injury research. OBJECTIVE: To determine whether serial in vivo imaging of nerve regeneration in the transgenic rat model is possible, facial nerve regeneration was imaged under the main paradigms of facial nerve injury and reconstruction. DESIGN, SETTING, AND PARTICIPANTS: Fifteen male Thy1-GFP rats, which express green fluorescent protein (GFP) in their neural structures, were divided into 3 groups in the laboratory: crush-injury, direct repair, and cross-face nerve grafting (30-mm graft length). The distal nerve stump or nerve graft was predegenerated for 2 weeks. The facial nerve of the transgenic rats was serially imaged at the time of operation and after 2, 4, and 8 weeks of regeneration. The imaging was performed under a GFP-MDS-96/BN excitation stand (BLS Ltd). INTERVENTION OR EXPOSURE: Facial nerve injury. MAIN OUTCOME AND MEASURE: Optical fluorescence of regenerating facial nerve axons. RESULTS: Serial in vivo imaging of the regeneration of GFP-positive axons in the Thy1-GFP rat model is possible. All animals survived the short imaging procedures well, and nerve regeneration was followed over clinically relevant distances. The predegeneration of the distal nerve stump or the cross-face nerve graft was, however, necessary to image the regeneration front at early time points. Crush injury was not suitable to sufficiently predegenerate the nerve (and to allow for degradation of the GFP through Wallerian degeneration). After direct repair, axons regenerated over the coaptation site in between 2 and 4 weeks. The GFP-positive nerve fibers reached the distal end of the 30-mm-long cross-face nervegrafts after 4 to 8 weeks of regeneration. CONCLUSIONS AND RELEVANCE: The time course of facial nerve regeneration was studied by serial in vivo imaging in the transgenic rat model. Nerve regeneration was followed over clinically relevant distances in a small number of experimental animals, as they were subsequently imaged at multiple time points. The Thy1-GFP rat model will help improve clinical outcomes of facial reanimation surgery through improving the knowledge of facial nerve regeneration after surgical procedures. LEVEL OF EVIDENCE: NA.

The ErbB2 inhibitor Herceptin (Trastuzumab) promotes axonal outgrowth four weeks after acute nerve transection and repair.

Accumulating evidence suggests that neuregulin, a potent Schwann cell mitogen, and its receptor, ErbB2, have an important role in regulating peripheral nerve regeneration. We hypothesized that Herceptin (Trastuzumab), a monoclonal antibody that binds ErbB2, would disrupt ErbB2 signaling, allowing us to evaluate ErbB2's importance in peripheral nerve regeneration. In this study, the extent of peripheral motor and sensory nerve regeneration and distal axonal outgrowth was analyzed two and four weeks after common peroneal (CP) nerve injury in rats. Outcomes analyzed included neuron counts after retrograde labeling, histomorphometry, and protein analysis. The data analysis revealed that there was no impact of Herceptin administration on either the numbers of motor or sensory neurons that regenerated their axons but histomorphometry revealed that Herceptin significantly increased the number of regenerated axons in the distal repaired nerve after 4 weeks. Protein analysis with Western blotting revealed no difference in either expression levels of ErbB2 or the amount of activated, phosphorylated ErbB2 in injured nerves. In conclusion, administration of the ErbB2 receptor inhibitor after nerve transection and surgical repair did not alter the number of regenerating neurons but markedly increased the number of regenerated axons per neuron in the distal nerve stump. Enhanced axon outgrowth in the presence of this ErbB2 inhibitor indicates that ErbB2 signaling may limit the numbers of axons that are emitted from each regenerating neuron.

Facial synkinesia before and after surgical reanimation of the paralyzed face.

BACKGROUND: Facial synkinesia is a common sequela of facial palsy, affecting 15 to 20 percent of patients. The rate of postoperative synkinesia after facial reanimation is not clearly established. The severity and type of synkinesia determine the degree of clinical relevance. METHODS: One hundred sixty-seven patients with facial palsy were included in this retrospective cohort study. Three-dimensional video analysis of facial movements was performed preoperatively and 18 months after facial reanimation. The severity of synkinesia was rated subjectively on a four-degree severity scale. Objective three-dimensional analysis of synkinesia was performed on patients with 18-month follow-up times. RESULTS: Preoperatively, 84.4 percent of patients were not affected by synkinesia, 9 percent presented with mild synkinesia, 4.2 percent presented with moderate synkinesia, and 2.4 percent presented with severe synkinesia. Postoperatively, 51 percent of all patients presented with facial synkinesia (41.8 percent mild, 17.3 percent moderate, and 1 percent severe synkinesia; some patients had more than one type). Patients treated with territorially differentiated gracilis muscle transplantation were most frequently affected (69.8 percent), followed by patients treated with gracilis muscle transplantation in combination with temporalis muscle transposition to the eye (51.8 percent). Oculo-oral synkinesia was the most frequent form of synkinesia. CONCLUSIONS: After surgical reanimation of the paralyzed face, half of the patients presented with synkinesia. The majority of patients developed mild or moderate forms of synkinesia; therefore, the clinical relevance of synkinesia has to be seen in the context of total facial function. Because of the high prevalence of synkinesia, it should be documented and addressed in patients undergoing facial reanimation. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Comparison of three-dimensional surface-imaging systems.

BACKGROUND: In recent decades, three-dimensional (3D) surface-imaging technologies have gained popularity worldwide, but because most published articles that mention them are technical, clinicians often have difficulties gaining a proper understanding of them. This article aims to provide the reader with relevant information on 3D surface-imaging systems. In it, we compare the most recent technologies to reveal their differences. METHODS: We have accessed five international companies with the latest technologies in 3D surface-imaging systems: 3dMD, Axisthree, Canfield, Crisalix and Dimensional Imaging (Di3D; in alphabetical order). We evaluated their technical equipment, independent validation studies and corporate backgrounds. RESULTS: The fastest capturing devices are the 3dMD and Di3D systems, capable of capturing images within 1.5 and 1 ms, respectively. All companies provide software for tissue modifications. Additionally, 3dMD, Canfield and Di3D can fuse computed tomography (CT)/cone-beam computed tomography (CBCT) images into their 3D surface-imaging data. 3dMD and Di3D provide 4D capture systems, which allow capturing the movement of a 3D surface over time. Crisalix greatly differs from the other four systems as it is purely web based and realised via cloud computing. CONCLUSION: 3D surface-imaging systems are becoming important in today's plastic surgical set-ups, taking surgeons to a new level of communication with patients, surgical planning and outcome evaluation. Technologies used in 3D surface-imaging systems and their intended field of application vary within the companies evaluated. Potential users should define their requirements and assignment of 3D surface-imaging systems in their clinical as research environment before making the final decision for purchase.

Up-regulation of two distinct p53-DNA binding functions by covalent poly(ADP-ribosyl)ation: transactivating and single strand break sensing.

We used a [(32)P] p53 sequence-specific oligodeoxynucleotide and Electrophoretic-Mobility-Shift-Assays to monitor p53 DNA sequence-specific binding with p53-R267W, a nonbinding point mutant; and p53-Δ30, a deletion-mutant which lacks the carboxy-terminus that recognizes DNA-strand-breaks. Recombinant p53 and poly(ADP-ribose)polymerase-1 (PARP-1) were incubated with labeled ßNAD(+) with/without DNA. The poly(ADP-ribosyl)ation of each protein increased with incubation-time and ßNAD(+) and p53 concentration(s). Since p53-Δ30 was efficiently labeled, poly(ADP-ribosyl)ation target site(s) of wt-p53 must reside outside its carboxy-terminal-domain. The poly(ADP-ribosyl)ation of p53-Δ30 did not diminish its DNA binding; Instead, it enhanced DNA-sequence-specific-binding. Therefore, we conclude that DNA-sequence-specific-binding and DNA-nick-sensing of mutant-p53 are differentially regulated by poly(ADP-ribosyl)ation.

p53-autoantibody may be more sensitive than CA-125 in monitoring microscopic and macroscopic residual disease after primary therapy for epithelial ovarian cancer.

PURPOSE: To evaluate the use of p53-autoantibodies (p53-aab) for monitoring minimal disease after standard therapy of advanced epithelial ovarian cancer (EOC). METHODS: Retrospective analysis of p53-aab in preoperative and long-term follow-up serum samples from 10 patients selected for representing three relevant EOC subgroups: platinum-sensitive disease after macroscopic complete debulking (n = 4) and platinum-sensitive (n = 3) or platinum-resistant disease (n = 3), both after suboptimal debulking with residual tumor of <1 cm diameter. p53-aab levels were quantified by a sandwich ELISA in two independent experiments. CA-125 values of all samples and clinical information were retrieved from medical records. RESULTS: Patients with early relapse (median PFS 7 months, n = 8) had high p53-aab levels throughout follow-up while CA-125 values had dropped below the cut-off after primary surgery during or after chemotherapy in these cases. Patients with seroconversion to p53-aab negativity experienced prolonged PFS (n = 2; #1: 50 months, #2: no evidence of disease for 36 months until last follow-up). Continued p53-aab positivity was not related to the resection status or platinum sensitivity. CONCLUSIONS: p53-autoantibodies may be a highly sensitive marker for minimal residual tumor mass after surgery and/or chemotherapy rather than standard CA-125, possibly due to the different nature of these markers. CA-125 released by cancer cells is related to tumor mass, whereas p53-aab levels can indicate the presence of few tumor cells due to amplification by the immune system. Seroconversion of p53-aab could be associated with long-term survival.

Anatomy of the sural nerve: cadaver study and literature review.

BACKGROUND: The sural nerve is commonly used as donor for nerve grafting. Contrary to its constant retromalleolar position, formation and course of the proximal sural nerve show great variability. The coexistence of different and deceptive terminologies contributes to the complexity, and reviewing the international literature is confusing. Because detailed anatomical knowledge is essential for efficient and safe sural nerve harvesting, this study aims to bring clarity. METHODS: Previous sural nerve reports listed in the PubMed database and established anatomical textbooks were reviewed. Different terminologies were compared and adjusted. Anatomical details and variations were noted. Subtle prospective anatomical dissections and comparison with actual data followed. RESULTS: Two hundred twenty-one relevant reports were identified and worked up going back to the nineteenth century. Fourteen established German and English language anatomical textbooks were reviewed. Thirty lower limbs were dissected. In total, this study pools the information of more than 2500 sural nerves. CONCLUSIONS: This study covers all information about the sural nerve anatomy published internationally. The coexistence of different and confusing terminologies is pinpointed and adjusted to allow comparison of previous reports and to gain a coordinated data pool of more than 2500 investigated sural nerves. Detailed features are clearly described and summarized, findings from the authors' own prospective dissections complete these data, and the prior existing anatomical confusion is resolved. Finally, clinical implications are described.

Prospective study on harvesting autologous bone grafts from the anterior iliac crest using a new specialized reamer.

The iliac crest remains the most frequent donor site for bone harvesting. Despite the surgical access to the iliac crest being relatively simple and the operation being carried out regularly, there are frequent complications. Therefore, a new, manual iliac crest reamer (R group) was compared to the classical harvesting of a corticocancellous bone graft by means of an oscillating saw (Con group) in a prospective study on 80 consecutive patients having hand surgery. Follow-up time was 3 months. Operation time and incidence of hematomas, seromas, and paresthesias in the R group were significantly shorter and less, respectively, than in the Con group. Pain at harvest site measured with the visual analogue scale (VAS) at 5 days, 6 weeks, and 12 weeks postoperatively was significantly less in group R as well. The utilization of the iliac crest reamer allows bone graft harvest in a relatively quick and simple operation with relatively few complications but with the limitation in that the maximum diameter of a bone cylinder that it can harvest is 20 mm.

Role of KCNQ channels in skeletal muscle arteries and periadventitial vascular dysfunction.

KCNQ channels have been identified in arterial smooth muscle. However, their role in vasoregulation and chronic vascular diseases remains elusive. We tested the hypothesis that KCNQ channels contribute to periadventitial vasoregulation in peripheral skeletal muscle arteries by perivascular adipose tissue and that they represent novel targets to rescue periadventitial vascular dysfunction. Two models, spontaneously hypertensive rats and New Zealand obese mice, were studied using quantitative polymerase chain reaction, the patch-clamp technique, membrane potential measurements, myography of isolated vessels, and blood pressure telemetry. In rat Gracilis muscle arteries, anticontractile effects of perivascular fat were inhibited by the KCNQ channel blockers XE991 and linopirdine but not by other selective K(+) channel inhibitors. Accordingly, XE991 and linopirdine blocked noninactivating K(+) currents in freshly isolated Gracilis artery smooth muscle cells. mRNAs of several KCNQ channel subtypes were detected in those arteries, with KCNQ4 channels being dominant. In spontaneously hypertensive rats, the anticontractile effect of perivascular fat in Gracilis muscle arteries was largely reduced compared with Wistar rats. However, the vasodilator effects of KCNQ channel openers and mRNA expression of KCNQ channels were normal. Furthermore, KCNQ channel openers restored the diminished anticontractile effects of perivascular fat in spontaneously hypertensive rats. Moreover, KCNQ channel openers reduced arterial blood pressure in both models of hypertension independent of ganglionic blockade. Thus, our data suggest that KCNQ channels play a pivotal role in periadventitial vasoregulation of peripheral skeletal muscle arteries, and KCNQ channel opening may be an effective mechanism to improve impaired periadventitial vasoregulation and associated hypertension.

Prospective evaluation of a single-sided innervated gluteal artery perforator flap for reconstruction for extensive and recurrent pilonidal sinus disease: functional, aesthetic, and patient-reported long-term outcomes.

BACKGROUND: Treating large and extensive pilonidal sinus disease is a challenging task. Long-term reports on flaps suitable for coverage of large, wide, local-excision defects are sparse. We prospectively evaluated data with a minimum 1-year follow-up of the use of a single-sided, innervated, superior gluteal artery perforator flap. METHODS: Twenty-one patients (1 woman, 20 men) with a median age of 26 years (min - max = 18 - 46) were included in the study period from September 2005 to April 2010. We recorded flap size, major and minor complications, hospital length of stay, impairment in activities of daily living, pain, aesthetic outcomes, and sensibility in the gluteal region (PSSD, pressure-specified sensory device) at 6 and 12 months postoperatively. RESULTS: The mean defect size (±SD) was 13.0 ± 1.9 × 8.6 ± 1.3 × 5.5 ± 1.2 cm (height × width × depth), and median length of hospital stay was 9 days (range = 7-11). Only two patients developed minor wound-healing complications. Visual analog pain scales significantly improved, with no pain detectable at 12 months postoperatively (p < 0.0001). The aesthetic appearance of the results was good in the majority of patients (61.9-85.7 %). PSSD showed gradual normalization, with retained sensibility in the flap area over 12 months postoperatively (p = 0.0232). During the median 36-month (range = 20-60) follow-up, we have not observed any recurrence in the operated area. CONCLUSIONS: The innervated superior gluteal artery perforator flap is a useful technique for covering large and recurrent pilonidal sinus defects following wide local excision and represents an excellent tool in the surgical armamentarium for achieving long-lasting outcomes in this young group of patients.