130,367 research outputs found
Perforator-to-perforator anastomosis as a salvage procedure during harvest of a perforator flap
No full textPerforator-based Adipofascial Flaps and ADM: A Novel Combined Approach to Distal Lower Extremity Defects
No full textBackground: Due to the wide spectrum of lower extremity defect presentation, various reconstructive techniques are available. Classic adipofascial flaps are still a second choice. The authors described a new multistage reconstructive approach with perforator-based pedicled adipofascial flap. Methods: This retrospective study analyzed data of 23 patients undergoing adipofascial flap reconstruction after distal leg trauma between June 2017 and January 2020. A reconstructive approach with an adipofascial flap followed by a skin graft was used in all patients. Patients were divided into two treatment groups, and in only one treatment group, an acellular dermal matrix was placed above the adipofascial flap during the first stage of the reconstruction. Negative pressure wound therapy was applied to both groups. Surgical technique, outcomes, and complications were discussed. Results: All patients achieved complete healing, and no flap loss was reported. Minor complications occurred in four patients; all were treated conservatively on outpatient basis. The surgical and aesthetic results were evaluated as satisfactory from both patients and professionals. However, the group treated with acellular dermal matrix showed a lower complication rate, and resulted significantly more satisfied with the overall results and in several domains of the questionnaire administered postoperatively (P < 0.05). Conclusions: The adipofascial flap is a safe and effective approach for the reconstruction of small-to-medium-sized defects of the distal lower extremity. Our two-stage reconstructive approach maximizes the pearls offered by the established technique; the dermal matrix guarantees a layered reconstruction optimizing the surgical and aesthetic outcomes of the skin graft with minimal donor site morbidity
Experience in reconstruction of esophagus, epiglottis, and upper trachea due to caustic injuries in pediatric patients and establishment of algorithm
No full textBackground: Unintentional swallowing of corrosive agents cause problems in the pediatric population. Swallowing dysfunction can be seen after injuring the pharynx and/or epiglottis which leads to the obstruction of esophagus. An algorithm was established taking into account the injury to the epiglottis and restoring gastrointestinal continuity with isolated or combine free and or supercharged jejunum flap, or supercharged colon transposition flap. Methods: Seventeen patients between the ages of 3 and 16 (mean age: 7.7) were treated between 1985 and 2019. Three different procedures were performed based on endoscopic findings; for patients with no or minimal damage to epiglottis, pedicled colon transposition was done in 12 cases. For patients with epiglottic scarring or edema, a two-stage reconstruction was performed. In the first stage, free jejunum flap was implemented to the pharynx to facilitate food passage, followed by a pedicled jejunum in two cases, or a pedicled colon transposition in two cases to provide gastrointestinal continuity. For one patient with severe epiglottic scarring, a free jejunal flap was used as a diversion conduit in the first stage, followed by supercharged colon transposition to restore gastrointestinal continuity. Results: Supercharged intestinal flaps were harvested with 3–4 cm of extra intestinal tissue than the measured thoracic portion in each individual in order to reach the hypopharyngeal region. The size of the free jejunal flaps were 10 cm. Oral feeding was initiated on the eighth postoperative day. Partial loss of the anterior wall of the jejunal flap was seen in one case, in which a free anterolateral thigh–vastus lateralis musculocutaneous flap was used for reconstruction. The mean follow-up time was 5.1 years and there was no stricture in the final outcome. Conclusion: A competent epiglottis is essential for proper swallowing reflex. Meticulous microsurgical dissection and performing supercharged intestinal flaps provide a complication-free end result
The Effect of Leg Dominance in Patients on Perforator-Based Flaps Elevated From the Lower Extremities
No full textBackground: The lower extremities are the largest donor sites in the body for perforator flap reconstruction. Multislice row computed tomography angiography allows for a multiplanar assessment of perforators using a large number of three-dimensional images with high resolution. In this study, the effect of leg dominance on perforator flap donor site preference was investigated radiologically to increase preoperative perforator mapping precision and surgical success. Patients and Methods: The study included 40 patients. Superior gluteal artery perforator (SGAP) flap, inferior gluteal artery perforator (IGAP) flap, superficial circumflex iliac artery perforator flap, anterolateral thigh (ALT) flap, profunda artery perforator (PAP) flap, medial sural artery perforator (MSAP) flap, peroneal artery perforator (PP) flap, and posterior tibial artery perforator (PTAP) flap were analyzed according to their number of perforators (> 0.8-mm perforators counted, number of larger perforators [nLP]), dominant perforator diameter (DPD), related muscle thickness (RMT), and related subcutaneous tissue thickness (RSTT) in each leg. Results: Of these 40 patients, 35 (87.5%) were right-leg dominant and 5 (12.5%) were left-leg dominant. The dominant leg had higher DPD for MSAP, PTAP, and PP than the nondominant leg (p = 0.08, p = 0.06, and p = 0.06, respectively). The dominant leg had a significantly higher nLP (> 0.8 mm) in MSAP, PTAP, and PP flaps than the nondominant leg (p < 0.05). Except for the PAP flap (adductor magnus muscle; p > 0.05), RMT of all other perforator flaps (SGAP, IGAP, ALT, MSAP, PTAP, and PP) was statistically higher in the dominant leg (p < 0.05). There was no statistically significant difference in RSTT between any of the two groups (p > 0.05). Conclusion: According to findings, the dominant leg could be considered a donor site preference to improve surgical outcomes and reduce microsurgical complications due to an increased nLP, perforator diameter, and RMT
Management of Medially Displaced Sub-Condylar Mandibular Fractures in Pediatric Population Using Novel Atraumatic Approach
No full textABSTRACT: The appropriate treatment of pediatric mandibular condyle fractures is subject to much debate and concern among surgeons, with improper treatment potentially resulting in a number of adverse outcomes. Such outcomes include the disruption of mandible growth, decreased posterior facial height, facial asymmetry, and temporomandibular joint ankylosis. Several surgical and nonsurgical approaches to these fractures have been described in the literature; however, each one carries its own risk of various complications. In this study, the authors illustrate a new atraumatic approach for mild to moderately displaced subcondylar fractures, with least possible complications and unexpected outcomes. In this study, 6 patients (2 female and 4 male) with unilateral medially displaced condylar base and neck fractures, angulated between 30 and 45 degrees, were treated using a novel intraoral approach. The follow-up period varied from 12 to 18 months. All patients achieved normal occlusion and had painless functioning of the temporomandibular joint with proper mouth opening (>35 mm) without any recurrence at long term follow up. This minimally invasive approach could eliminate the possibility of major complications and be considered a safe and feasible surgical technique for certain cases of pediatric mandibular condyle fracture
Risks of laparoscopic harvest of free intestinal flaps for esophageal reconstruction
No full textBackground: Performing ablative surgery using an laparoscope is a common practice. However, its use in the harvest of a segment of intestine for reconstruction has 2 major challenges: risk of damage to the vascular pedicle of the flap as well as to the vessels of other parts of the intestine that remain in the peritoneal cavity and risk of damage to the intestinal flap while pulling it out through a small opening in the abdominal wall. The aim of this study was to report advantages and disadvantages of harvesting free intestinal flaps using the laparoscopic method, explaining the challenges faced and lessons learned from this experience. Patients and Methods: Free intestinal flaps were harvested by laparoscopy in 12 patients aged 28 to 63 years. There were 9 free jejunal flaps for the reconstruction of the cervical esophagus and 3 ileocolic flaps for the reconstruction of both the cervical esophagus and voice reconstruction. Results: In 1 patient, laparoscopy was converted to laparotomy due to previous colectomy, which resulted in compromised circulation to the rest of the colon. One jejunal flap had leakage at its pharyngeal end; therefore, a pectoralis major myocutaneous flap was used for closure. In addition, 1 ileocolic flap had partial loss of its anterior wall, and a free anterolateral flap was used as a patch for closure. Furthermore, it was very difficult to harvest 1 free jejunal flap due to the thick and fat mesentery. Conclusion: Prolonged operative times, unexpected leakage at the anastomosis sites, partial loss of flaps, possible risk of vascular pedicle damage or venous compromise, demanding pedicle dissection in obese patients, and requirement of conversion to laparotomy are the major drawbacks of harvesting free intestinal flaps by laparoscopy
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
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