Superficial circumflex iliac artery perforator flap on extremity defects - case series.

BACKGROUND: Reconstruction of upper and lower extremity defects can be challenging. Especially in distal parts, relatively thin flaps are needed not to interfere with the function or aesthetic appearance of the extremity. The superficial circumflex iliac artery perforator (SCIP) flap represents a powerful but still not so commonly used tool for this kind of reconstruction. In this article, we present several cases of the use of the SCIP flap for extremity defect coverage. CASE SERIES: We present five cases (three men and two women) of upper or lower extremities defect coverage with a SCIP flap performed between January and June 2021 at our department. The mean age of the patients was 43 years (28-67 years). The body mass index was 28.6 on average. Two defects were located on hands and three defects on lower extremities. In three cases, the cause of the defect was trauma, and in the remaining two, it was a tumor resection. The mean thickness of the flap was 9.4 mm. We experienced no total flap loss and no revision surgery for ischemia or congestion was needed. One of the patients developed marginal flap necrosis, which was corrected by necrectomy and direct skin closure. CONCLUSION: Our case series demonstrates the possible use of the SCIP flap in the reconstruction of upper and lower extremities. With its thinness, low donor-site morbidity, and ease of harvest, we recommend the SCIP flap to be considered as one of the primary reconstructive options for various extremities defects.

miR-183/96/182 cluster is an important morphogenetic factor targeting PAX6 expression in differentiating human retinal organoids.

MicroRNAs (miRNAs), a class of small, noncoding RNA molecules represent important regulators of gene expression. Recent reports have implicated their role in the cell specification process acting as "fine-tuners" to ensure the precise gene expression at the specific stage of cell differentiation. Here, we used retinal organoids differentiated from human pluripotent stem cells (hPSCs) as a model to closely investigate the role of a sensory organ-specific and evolutionary conserved miR-183/96/182 cluster. Using a miRNA tough decoy approach, we inhibited the miR-183/96/182 cluster in hPSCs. Inhibition of the miRNA cluster resulted in an increased expansion of neuroepithelium leading to abnormal "bulged" neural retina in organoids, associated with upregulation of neural-specific and retinal-specific genes. Importantly, we identified PAX6, a well-known essential gene in neuroectoderm specification, as a target of the miR-183/96/182 cluster members. Taken together, the miR-183/96/182 cluster not only represents an important regulator of PAX6 expression, but it also plays a crucial role in retinal tissue morphogenesis.

Toward structured macroporous hydrogel composites: electron beam-initiated polymerization of layered cryogels.

The ability to tailor mechanical properties and architecture is crucial in creating macroporous hydrogel scaffolds for tissue engineering. In the present work, a technique for the modification of the pore size and stiffness of acrylamide-based cryogels is demonstrated via the regulation of an electron beam irradiation dose. The samples were characterized by equilibrium swelling measurements, light and scanning electron microscopy, mercury porosimetry, Brunauer-Emmett-Teller surface area analysis, and stiffness measurements. Their properties were compared to cryogels prepared by a standard redox-initiated radical polymerization. A (125)I radiolabeled azidopentanoyl-GGGRGDSGGGY-NH2 peptide was bound to the surface to determine the concentration of the adhesive sites available for biomimetic modification. The functionality of the prepared substrates was evaluated by in vitro cultivation of adipose-derived stem cells. Moreover, the feasibility of preparing layered cryogels was demonstrated. This may be the key to the future preparation of complex hydrogel-based scaffolds to mimic the extracellular microenvironment in a wide range of applications.

New technique of immediate nipple reconstruction during immediate autologous DIEP or MS-TRAM breast reconstruction.

BACKGROUND: Reconstruction of the nipple-areola complex is the final step in surgical restoration of the breast. Usually considered a secondary complement to breast reconstruction, nipple-areola creation is ordinarily done after an interval of several months using different techniques involving local flaps or composite graft from the opposite nipple. METHODS: Because the position of the nipple-areola complex is well defined from the outset in skin-sparing mastectomy, the authors propose a new technique of immediate nipple reconstruction using the skin envelope after skin-sparing mastectomy. A modified wise pattern design of skin-sparing mastectomy with 3 local flaps is used. The dermal-fat flaps are lifted and sutured together to form the new nipple. RESULTS: Seventeen patients (average age, 47 years; range, 33-58 years) underwent immediate nipple reconstruction between March 2010 and January 2012 (11 bilateral and 6 unilateral cases). Average follow-up was 13 months (range, 2-25 months). Aesthetic results were evaluated retrospectively from photographic documentation. A minimum average score of 7.2 points was achieved in all evaluated criteria using a 10-point scale. Patient satisfaction with nipple reconstruction was studied by means of a questionnaire. The shape of the nipple received an average of 9.7 points and the position of the nipple 9.9 points on the 10-point scale; 77% of patients were also very satisfied with nipple sensitivity. CONCLUSIONS: One-stage nipple reconstruction with immediate breast reconstruction using our technique of 3 local flaps on skin envelope flap is possible. This simple, reliable, and rapid technique gives stable aesthetic results over time. Reconstruction may be completed sooner and with fewer procedures. Nipple reconstruction should no longer be considered as a secondary complement to immediate breast reconstruction using deep inferior epigastric perforator or muscle-sparing transverse rectus abdominis myocutaneous flap. Our technique is suitable for patients with ptotic or hypertrophic breasts.

Restoring the spontaneous smile through free functional muscle transfer. A systematic review and meta-analysis of the last twenty years' experience.

BACKGROUND: The recovery of the spontaneous smile has become a primary focus in facial reanimation surgery and its major determinant is the selected neurotizer. We aimed to compare the spontaneity outcomes of the most preferred neurotization methods in free functional muscle transfer for long-standing facial paralysis. METHODS: The Embase, Ovid Medline, and PubMed databases were queried with 21 keywords. All clinical studies from the last 20 years reporting the postoperative spontaneity rate for specified neurotization strategies [cross-face nerve graft (CFNG), contralateral facial nerve (CLFN), motor nerve to the masseter (MNM), and dual innervation (DI)] were included. A meta-analysis of prevalence was performed using Freeman-Tukey double arcsine transformation, I2 statistic, and generic inverse variance with a random-effects model. Risk Of Bias In Non-randomized Studies of Interventions and Newcastle-Ottawa scale were used to assess bias and study quality. RESULTS: The literature search produced 2613 results and 473 unique citations for facial reanimation. Twenty-nine studies including 2046 patients were included in the systematic review. A meta-analysis of eligible data (1952 observations from 23 studies) showed statistically significant differences between the groups (CFNG: 0.94; 95% confidence interval [CI], 0.76-1.00, CLFN: 0.91; 95% CI, 0.49-1.00, MNM: 0.26; 95% CI, 0.05-0.54, DI: 0.98; 95% CI, 0.90-1.00, P < 0.001). In pairwise comparisons, statistically significant differences were found between MNM and other neurotization strategies (P < 0.001 in CFNG compared with MNM, P = 0.013 for CLFN compared with MNM, P < 0.001 for DI compared with MNM). CONCLUSIONS: DI- and CLFN-driven strategies achieved the most promising outcomes, whereas MNM showed the potential to elicit spontaneous smile at a lower extent. Our meta-analysis was limited primarily by incongruency between spontaneity assessment systems. Consensus on a standardized tool would enable more effective comparisons of the outcomes.

Surgeon-conducted color Doppler ultrasound deep inferior epigastric artery perforator mapping: A cohort study and learning curve assessment.

BACKGROUND: Perforator mapping using diagnostic methods facilitates deep inferior epigastric perforator (DIEP) flap planning. Computed tomographic angiography (CTA) is a well-proven tool for perforator mapping. However, the benefits of color Doppler ultrasonography (CDU) are as follows: 1) CDU involves dynamic real-time examination and 2) does not use radiation. Comparing the accuracies of both methods in a cohort of patients, this study aimed to evaluate the learning curve of surgeon-conducted CDU perforator mapping. METHODS: Twenty patients undergoing DIEP flap breast reconstruction were enrolled in a cohort study. All patients underwent CTA perforator mapping preoperatively. XY coordinates of significant perforators were subtracted by a radiologist. A single surgeon (sonographer) with minimal experience with CDU performed CDU perforator mapping, including XY coordinates subtraction. The sonographer was blinded to the CTA data. The reference coordinates of dissected perforators were measured during surgery. Deviations from reference coordinates for both methods were compared, and CDU mapping learning curve was assessed using Joinpoint Regression. RESULTS: We included 20 women (32 DIEP flaps and 59 dissected perforators). The mean deviation between mapped and reference coordinates was 1.00 (0.50-1.12) cm for CDU and 0.71 (0.50-1.12) cm for CTA. The learning curve of CDU mapping showed the breaking point after the seventh patient (≈ 21 localized perforators). After the breaking point, no significant differences between the deviations of both methods were found (p = 0.980). CONCLUSION: A limited number of examinations were needed for the surgeon to learn CDU DIEA perforator mapping with accuracy similar to that of CTA mapping.

Donor nerve selection in free gracilis muscle transfer for facial reanimation. A systematic review and meta-analysis of clinical outcomes.

BACKGROUND: One of the critical factors in facial reanimation is selecting the donor nerve. The most favored neurotizers are the contralateral facial nerve with a cross-face nerve graft (CFNG) and motor nerve to the masseter (MNM). A relatively new dual innervation (DI) method has shown successful results. This study aimed to compare the clinical outcomes of different neurotization strategies for free gracilis muscle transfer (FGMT). METHODS: The Scopus and WoS databases were queried with 21 keywords. Three-stage article selection was performed for the systematic review. Articles presenting quantitative data for commissure excursion and facial symmetry were included in meta-analysis, using random-effects model. ROBINS-I tool and Newcastle-Ottawa scale were used to assess bias and study quality. RESULTS: One hundred forty-seven articles containing FGMT were systematically reviewed. Most studies indicated CFNG as the first choice. MNM was primarily indicated in bilateral palsy and in elderly. Clinical outcomes of DI studies were promising. 13 studies including 435 observations (179 CFNG, 182 MNM, 74 DI) were eligible for meta-analysis. The mean change in commissure excursion was 7.15 mm (95% CI: 4.57-9.72) for CFNG, 8.46 mm (95% CI: 6.86-10.06) for MNM, and 5.18 mm (95% CI: 4.01-6.34) for DI. In pairwise comparisons, a significant difference was found between MNM and DI (p = 0.0011), despite the superior outcomes described in DI studies. No statistically significant difference was found in resting and smile symmetry (p = 0.625, p = 0.780). CONCLUSIONS: CFNG is the most preferred neurotizer, and MNM is a reliable second option. Outcomes of DI studies are promising, but more comparison studies are needed to draw conclusions. Our meta-analysis was limited by incompatibility of the assessment scales. Consensus on a standardized assessment system would add value to future studies.

Color Doppler ultrasound versus CT angiography for DIEP flap planning: A randomized controlled trial.

BACKGROUND: Identifying relevant perforators is crucial in planning a deep inferior epigastric perforator (DIEP) flap. Color Doppler ultrasonography (CDU) has gained popularity for localizing perforators; however, current evidence on its efficiency is still inconclusive. This study aimed to compare the efficiency of CDU with that of computed tomography angiography (CTA) in localizing and selecting the relevant perforators. METHODS: In this randomized controlled trial, 60 patients undergoing DIEP flap breast reconstruction (uni- or bilateral) were randomly assigned to the CDU group (i.e., CDU was performed to map and select the relevant perforators preoperatively) or the CTA+CDU group (i.e., mapping was based on CTA and supplemented by CDU). CDU was performed by the same surgeon with a well-defined sonography experience from our previous study. The reference XY coordinates of the dissected perforators were measured intraoperatively, and deviations from preoperatively deducted coordinates were calculated (ΔCDU or ΔCTA+CDU). The flaps were categorized according to the number of dissected perforators, and adherence to the preoperative strategy was evaluated. RESULTS: Overall, 22 patients (30 flaps) in the CTA+CDU group and 27 (39 flaps) patients in the CDU group were evaluated. The average ΔCDU (0.6 cm) was significantly lower than the average ΔCTA+CDU (1.0 cm) (p < 0.001). Adherence to the mapping-based dissection strategy was higher in the CDU group; however, the difference was insignificant (p = 0.092). CONCLUSION: CDU is not inferior to CTA + CDU in localizing and selecting relevant DIEA perforators. Therefore, CDU mapping is a possible complementary or substitute modality for CTA mapping.

Expandable Lung Epithelium Differentiated from Human Embryonic Stem Cells.

BACKGROUND: The progenitors to lung airway epithelium that are capable of long-term propagation may represent an attractive source of cells for cell-based therapies, disease modeling, toxicity testing, and others. Principally, there are two main options for obtaining lung epithelial progenitors: (i) direct isolation of endogenous progenitors from human lungs and (ii) in vitro differentiation from some other cell type. The prime candidates for the second approach are pluripotent stem cells, which may provide autologous and/or allogeneic cell resource in clinically relevant quality and quantity. METHODS: By exploiting the differentiation potential of human embryonic stem cells (hESC), here we derived expandable lung epithelium (ELEP) and established culture conditions for their long-term propagation (more than 6 months) in a monolayer culture without a need of 3D culture conditions and/or cell sorting steps, which minimizes potential variability of the outcome. RESULTS: These hESC-derived ELEP express NK2 Homeobox 1 (NKX2.1), a marker of early lung epithelial lineage, display properties of cells in early stages of surfactant production and are able to differentiate to cells exhibitting molecular and morphological characteristics of both respiratory epithelium of airway and alveolar regions. CONCLUSION: Expandable lung epithelium thus offer a stable, convenient, easily scalable and high-yielding cell source for applications in biomedicine.

Cleft palate caused by congenital teratoma.

A cleft palate results from incomplete fusion of the lateral palatine processes, the median nasal septum and the median palatine process. This case report describes a rare case of congenital teratoma originating from the nasal septum that may have interfered with the fusion of the palatal shelves during embryonic development, resulting in a cleft palate. An infant girl was born at 40 weeks of gestation weighing 3020 g with a complete cleft palate associated with a large central nasopharyngeal tumour. Computed tomography (CT) of the head showed a well defined mass of mixed density. The tumour was attached to the nasal septum in direct contact with the cleft palate. A biopsy confirmed the teratoma. Tumour resection was performed at 5 months, soft palate reconstruction at 7 months and hard palate closure at 14 months. There was no sign of local recurrence 1 year later. Most teratomas are benign and the prognosis is usually good. However, recurrence is not rare if germ cell carcinomatous foci are present within the teratoma. For these reasons, we advocate the use of a two-stage procedure in which closure of the cleft palate is postponed until histological examination confirms complete excision of the teratoma.

A Comprehensive In Vitro Comparison of Preparation Techniques for Fat Grafting.

BACKGROUND: Lipomodeling is a technique that uses the patient's own fat for tissue regeneration and augmentation. The extent of regenerative effect is reported to be determined by the numbers of adipose-derived stem cells and the viability of cells in processed adipose tissue which, together with other factors, influence the degree of graft retention. This study addresses whether differences exist in properties of fat graft obtained by three commonly used techniques. METHODS: Adipose tissue harvested from the hypogastric regions of 14 patients was processed by decantation, centrifugation, and membrane-based tissue filtration. The morphology of each preparation was assessed by electron microscopy and overall cell viability was assessed by live/dead assay. The number of adipose-derived stem cells was determined and their stem cell character was assessed by the presence of cell surface molecules (i.e., CD105, CD90, CD31, and CD45) and by their capacity to differentiate into adipogenic and osteogenic lineages. RESULTS: First, morphologies of processed fat samples obtained by individual procedures differed, but no preparation caused obvious damage to cellular or acellular components. Second, although the highest numbers of adipose-derived stem cells were contained in the upper fraction of centrifuged lipoaspirates, the difference between preparations was marginal. Third, the maximal concentration of adipose fraction (removal of watery component) of lipoaspirate was achieved by membrane-based tissue filtration. Finally, no significant differences in overall viability were detected. CONCLUSIONS: Properties of processed lipoaspirate were influenced by the preparation procedure. However, the differences were not dramatic; both centrifugation and membrane-based filtration are methods of choice whose selection depends on other criteria (e.g., practicality) for individual surgical settings.

Vasospasm of the flap pedicle: the effect of 11 of the most often used vasodilating drugs. Comparative study in a rat model.

BACKGROUND: There has been no review study published yet comparing the effects of the vasodilating drugs that are most often used in clinical practice empirically. The aim of the authors' study was to perform this comparison and to select the drugs that are able to release vasospasm and the drugs that reduce vasospasm duration most effectively in an experimental model in vivo. METHODS: Pedicled groin flaps were dissected in 300 male Wistar rats. Vasospasm was induced by tension applied on the pedicle in the axial direction using a 15-g weight. The blood perfusion of the flap was monitored using a laser Doppler device. The duration of vasospasm was defined as the time from the release of tension until blood flow began to rise. These times were detected using automated computerized detection. The effects of 11 different drugs were studied in 14 groups. The drugs were applied locally; some of them were tested in different concentrations or applied parenterally. RESULTS: Ten percent magnesium sulfate reduced the duration of vasospasm most effectively (p < 0.01). Verapamil applied locally and also pentoxifylline applied parenterally were also very effective. In contrast, the duration of vasospasm was extended after local application of 2% lidocaine (p < 0.01). CONCLUSIONS: The authors concluded that 10% magnesium sulfate applied locally has the best ability to relieve surgically induced vasospasm because of the highest level of significance and reliability. The finding that local application of 2% lidocaine prolongs vasospasm may be surprising.