Flap Tip Research Articles

Exploring the Reasons for Decrease in Binding Affinity of HIV-2 Against HIV-1 Protease Complex Using Interaction Entropy Under Polarized Force Field.

In this study, the differences of binding patterns between two type HIV (HIV-1 and HIV-2) protease and two inhibitors (darunavir and amprenavir) are analyzed and compared using the newly developed interaction entropy (IE) method for the entropy change calculation combined with the polarized force field. The functional role of protonation states in the two HIV-2 complexes is investigated and our study finds that the protonated OD1 atom of Asp25′ in B chain is the optimal choice. Those calculated binding free energies obtained from the polarized force field combined with IE method are significantly consistent with the experimental observed. The bridging water W301 is favorable to the binding of HIV-1 complexes; however, it is unfavorable to the HIV-2 complexes in current study. The volume of pocket, B-factor of Cα atoms and the distance of flap tip in HIV-2 complexes are smaller than that of HIV-1 consistently. These changes may cause localized rearrangement of residues lining their surface and finally result in the different binding mode for the two types HIV. Predicated hot-spot residues (Ala28/Ala28′, Ile50/Ile50′, and Ile84/Ile84′) are nearly same in the four systems. However, the contribution to the free energy of Asp30 residue is more favorable in HIV-1 system than in HIV-2 system. Current study, to some extent, reveals the origin for the decrease in binding affinity of inhibitors against HIV-2 compared with HIV-1 and will provides theoretical guidance for future design of potent dual inhibitors targeting two type HIV protease.

Comparing Z-Plasty versus Z-Plasty and Skin Grafting for Surgical Tension-Free Treatment of Post-Burn Elbow Contractures: A Randomized Clinical Trial

Background: Elbow contracture is a common incidence. It has surgical treatments such as scar release and skin graft, Z or V-Y plasty, and lateral or medial arm flap. In this study, we compared Z-plasty versus Z-plasty and skin grafting in the surgical tensionfree treatment of post-burn elbow contractures. Methods: 30 patients with elbow joint extension restriction participated in this randomized clinical trial in two groups: experimental (Z-plasty with skin graft) and control (Z-plasty alone) groups. In both groups, Z-plasty was designed with a 60 angle. In the experimental group, the flaps were rotated without tension, and then the upper and lower parts of the flaps were grafted by a midsplit-thickness skin graft. The surgery area was examined regarding infections, wound healing time, necrosis, and scar. Significant differences were evaluated using unpaired student t-test. Results: Only seven participants in the control group had complications. The statistical analysis of all variables in both groups showed that Z-plasty with skin graft treatment had a significantly better result than the Z-plasty alone (P = 0.006). However, the two groups showed no significant differences in terms of infection, flap tip necrosis, surgery site infection, and feeling of pressure in joint extension or scar recurrence (P = 0.273). Conclusions: Tension-free flap must be used in patients with mild or moderate wide elbow scar contracture. Combining Z-plasty with skin graft is easy and has better results than Z-plasty alone. It is recommended using this technique in patients with intraoperative flap tension.

Molecular Mechanisms of an All-Purpose Transcription Anti-Termination Factor

Bacteriophage λN protein, a paradigmatic anti-termination factor, binds nascent RNA and host Nus factors, rendering RNA polymerase resistant to all pause and termination signals. A 3.7 A-resolution cryo-electron microscopy structure and structure-informed functional analyses reveal an all-it-takes strategy, in which the intrinsically unstructured λN directly modifies RNA polymerase interactions with the nucleic acids and subverts essential functions of NusA, NusE and NusG to reprogram the transcriptional apparatus. λN repositions NusA and remodels the β-subunit flap tip to preclude folding of pause/termination RNA hairpins in the exit tunnel and disrupt termination-supporting interactions of the α-subunit C-terminal domains. λN invades and traverses the RNA polymerase catalytic cavity, stabilizing the hybrid and impeding pause/termination-related conformational changes. λN also binds upstream DNA, enhancing the weak anti-backtracking and anti-swiveling activities of NusG. Moreover, λN-repositioned NusA and NusE sequester the NusG C-terminal domain, counteracting ρ-dependent termination. Other anti-terminators likely utilize similar mechanisms to enable processive transcription.

Hatchet Flap With Transposed Nasal Inset for Midfacial Reconstruction

The purpose of this study is to report the surgical technique and functional outcomes of the hatchet flap with transposed nasal inset for midfacial defect repairs. An Institutional Review Board-approved, retrospective review was performed to identify patients treated using the hatchet flap with transposed nasal inset. Patient demographics, disease etiology, defect characteristics, and postoperative complications were collected from preoperative and follow-up visits. The hatchet flap with transposed nasal inset was performed in 5 patients between March 2016 and April 2017. Two patients developed mild transient ischemia of the nasal inset flap tip without necrosis. A suture granuloma was removed in 1 patient. No additional surgical procedures were required after the nasal inset cheek flap. The hatchet flap with transposed nasal inset is an effective procedure to address defects involving the upper cheek, lower eyelid, and medial canthus. Incorporation of the nasal inset helps prevent distortion of the ala and facilitates closure of the flap donor site. This technique may be employed in certain patients as an acceptable alternative to more extensive Mustardé or paramedian forehead flaps.

Tongue Flap Reconstruction in Carcinoma of Oral Cavity: An Institutional Experience.

Abundant blood supply of tongue permits various flap designs and makes it a good choice for reconstructing defects following resection of oral cancer. We aim to evaluate the reliability of tongue flap for small- and medium-size defects after resection of oral cancer in terms of viability, complications, and functional outcome. In this retrospective analysis, patients reconstructed with lateral tongue flaps after resection of oral cavity carcinoma from May 2011 to December 2017 were included. Forty-two patients underwent tongue flap reconstruction during the study period. Median size of defect was 3.5cm. Out of 42 patients, 27 had carcinoma of buccal mucosa and 8 had carcinoma of lower alveolus. Mandibular resection was performed in 30 patients. Neck was addressed in all 42 patients. Supraomohyoid neck dissection was done in 12 patients, while others had comprehensive neck dissection. Average time to harvest flap was 25min. There was no flap loss in the postoperative period. Three patients each developed flap tip necrosis and minor orocutaneous fistula that were managed conservatively. Subjective functional outcome was good to satisfactory in most patients (88%). Lateral tongue flap is a simple reliable flap for reconstruction of small- and medium-sized defects following resection of oral cavity cancers in terms of low morbidity and satisfactory functional outcomes. It obviates the need of distant tissue transfer.

Vascularized dermal autograft for the treatment of irreparable rotator cuff tears

Irreparable rotator cuff tears (IRCTs) are a challenging problem with diverse treatment modalities. We propose a technique for the treatment of IRCTs in which a vascularized dermal autograft is transferred to the posterosuperior region of the rotator cuff using the supraclavicular artery (SCA) island flap. Dissection of 11 fresh cadavers (19 shoulders) was performed, and the SCA island flap was harvested in all specimens. A full-thickness posterosuperior rotator cuff defect was created, and the flap was tunneled under the acromion and secured into position over the defect using multiple suture anchors. Simulated flap perfusion was then assessed, and flap measurements were recorded. There were 4 male and 7 female cadavers (19 shoulders). Flap perfusion was assessed in 10 shoulders. On average, the flap thickness was 4.7 mm (range, 3.5-7.1 mm); width, 32.6 mm (range, 25.5-38.0 mm); and length, 169.2 mm (range, 132.0-235.0 mm). The average distance from the flap tip to the Neviaser portal was 76.2 mm (range, 48.0-99.6 mm), and that from the flap tip to the anterolateral acromial edge was 54.1 mm (range, 29.5-75.1 mm). The pedicle-to-footprint distance was 113.7 mm (range, 88.5-147.0 mm). The average flap length exceeded the pedicle-to-footprint distance by 55.5 mm (range, 43.5-88.0 mm), indicating adequate excursion of the flap. All flaps demonstrated adequate simulated perfusion after fixation. The SCA island flap may be an option for a vascularized dermal autograft for IRCTs, as shown in this cadaveric study. This illustrates a possible technique with vascular viability.

Delayed bipedicled nasolabial flap in facial reconstruction.

BackgroundThe nasolabial flap is ideal for reconstruction of the nasal alar subunit due to its proximity, color and contour match, and well-placed donor scar. When raised as a random-pattern flap, there is a risk of vascular compromise to the tip with increased flap length and aggressive flap thinning. Surgical delay can greatly improve the chances of tip survival, allowing the harvest of longer flaps with greater reach.MethodsWe describe our technique of lengthening the nasolabial flap through multiple delay procedures. A bipedicled flap was first raised and then transferred as a unipedicled flap with a 6:1 length-to-width ratio. During the delay process, the flap tip was thinned to the subdermal layer.ResultsIn our case series of seven patients, defects as far as the medial canthal area and contralateral ala were reconstructed successfully with no incidence of tip necrosis or flap loss. The resultant flaps were thin enough to be folded over for the reconstruction of alar rim defects.ConclusionsWe highlight the success of our surgical technique in creating thin and robust nasolabial flaps for the reconstruction of full-thickness defects around the nose.

Spontaneous Synchronization of Beating Cilia: An Experimental Proof Using Vision-Based Control

This article investigates the formation of spontaneous coordination in a row of flexible 2D flaps (artificial cilia) in a chamber filled with a high viscous liquid (Re = 0.12). Each flap is driven individually to oscillate by a rotary motor with the root of the flap attached to its spindle axle. A computer-vision control loop tracks the flap tips online and toggles the axle rotation direction when the tips reach a pre-defined maximum excursion. This is a vision-controlled implementation of the so-called “geometric clutch” hypothesis. When running the control loop with the flaps in an inviscid reference situation (air), they remain in their individual phases for a long term. Then, the flaps are studied in the chamber filled with a highly viscous liquid, and the same control loop is started. The flexible flaps now undergo bending due to hydrodynamic coupling and come, after a maximum of 15 beats, into a synchronous metachronal coordination. The study proves in a macroscopic lab experiment that viscous coupling is sufficient to achieve spontaneous synchronization, even for a symmetric cilia shape and beat pattern.

Unsteady two-dimensional jet with flexible flaps at the channel exit

The present work studies the effect of passive exit flexibility on a two-dimensional starting jet. The exit flexibility is introduced by attaching two flexible (deformable) flaps at the jet exit of a high aspect ratio rectangular duct with the flaps initially being parallel to the channel walls. A controlled piston motion is used to generate the starting jet, which is composed of a rapid acceleration to a constant velocity ($U_{p}$) that is maintained for a given duration of time, after which it is brought to rest impulsively. The parameters which are varied include the flexural rigidity ($EI$) of the flaps, flap length ($L_{f}$) and piston speed ($U_{p}$), with measurements of the flap kinematics and flow field in each case. The flaps initially bulge due to the acceleration of the piston from rest, with this bulge growing in size and moving downstream as the flow develops, culminating in a large opening at the flap exit. Subsequently, the flaps return to their initial parallel position and remain there as long as the piston is in motion. Once the piston stops, the flaps collapse inwards due to fluid deceleration causing additional flow out of the flap region in the form of a jet that adds to the net amount of fluid pushed by the piston. We find that the flap kinematics is affected by the flap$EI$and$L_{f}$besides$U_{p}$. We define a non-dimensional flexural rigidity$EI^{\ast }=EI_{eq}/(1/2\unicode[STIX]{x1D70C}U_{p}^{2}L_{f}^{2}d)$, where$EI_{eq}$is an equivalent flexural rigidity which takes the self-weight of the flaps into account ($d=\text{channel width}$;$\unicode[STIX]{x1D70C}=$fluid density). We find that across different$EI_{eq}$,$L_{f}$, and piston speeds, the maximum opening of the flap tip and the time taken to reach this maximum opening in terms of$L/L_{f}$(where$L=\text{fluid slug length}$) fall on a single curve for all the cases studied, when plotted with$EI^{\ast }$. Particle image velocimetry measurements show that the motion of the flaps results in the formation of additional pairs of vortices when compared to the single vortex pair formed in the absence of flaps. The total final circulation coming out of the flap region remains nearly the same as that of the rigid exit case. However, the final fluid impulse is always found to be higher in the flap cases, with the fluid impulse in most flap cases being approximately two times the fluid impulse of the rigid exit case. This increase in impulse is shown to be linked to the fact that the centroids of vorticity get spread out more in the lateral direction due to the opening of the flaps. The increased impulse and the higher time rate of change of impulse, which is linked with force, suggest that introduction of flexible flaps can help improve thrust performance when looked at from a propulsion point of view.

Multi-view stereo in the operating room allows prediction of healing complications in a patient-specific model of reconstructive surgery

Excessive mechanical stress leads to wound healing complications following reconstructive surgery. However, this knowledge is not easily applicable in clinical scenarios due to the difficulty in measuring stress contours during complex tissue rearrangement procedures. Computational tools have been proposed as an alternative to address this need, but obtaining patient specific geometries with an affordable and flexible setup has remained a challenge. Here we present a methodology to determine the stress contours from a reconstructive procedure on a patient-specific finite element model based on multi-view stereo (MVS). MVS is a noninvasive technology that allows reconstruction of 3D geometries using a standard digital camera, making it ideal for the operating room. Finite element analysis can then be used on the patient-specific geometry to perform a virtual surgery and predict regions at risk of complications. We applied our approach to the case of a 7-year-old patient who was treated to correct a cranial contour deformity and resect two large areas of scalp scarring. The simulation showed several zones of high stress, particularly near the suture lines at the distal ends of the flaps. The patient did show delayed healing and partial flap tip necrosis at one of such predicted regions at the 30-day follow up visit. Our results further establish the application of computational tools in individualized medical scenarios to advance preoperative planing and anticipate regions of concern immediately after surgery.

Thoracoumbilical Flap: Anatomy, Technique, and Clinical Applications in Upper Limb Reconstruction in the Era of Microvascular Surgery.

Microvascular reconstruction is the standard of care for salvage of soft tissue defects in complex upper extremity due to their distinct advantages over the pedicled flaps. However, in the era of microsurgery, pedicled flaps have an acceptable significant role for reconstruction of complex soft tissue defects. The authors aim to demonstrate the versatility of pedicled thoracoumbilical flap (TUF) in selected clinical scenarios. Retrospective analysis of patients who underwent TUF for upper limb posttraumatic reconstruction was performed between January 2016 and October 2017. The demographic details, etiology, wound parameters, clinical circumstances, and complications were recorded. Ten patients were included in the retrospective case series. Out of them, nine of the patients had critical issues, which justified a pedicled TUF over free flap. The critical issues were severe comorbid illnesses ( n = 3), the paucity of recipient vessels ( n = 1), salvage of hand replant and revascularization ( n = 2), circumferential degloving injury to the multiple fingers and palm ( n = 1), coverage for metacarpal hand ( n = 1), and extensive scarring at the surgical site ( n = 1). Mean age was 34.4 years (range: 11-70 years), six of them were males, and four were females. Two patients had infections resulting in wound gaping. One of the patients had flap tip necrosis. Pedicled flaps have a significant acceptable role in this era of microsurgery, and a pedicled TUF is a versatile option for coverage of complex soft tissue defects of the forearm, wrist, hand, and fingers. This is a level IV, therapeutic, and retrospective study.

Evaluation of scrotal reconstruction with thigh flap

Background: Scrotal skin can be lost in many ways. Partial loss of scrotum is easy to manage but major scrotal skin loss represents a significant challenge to the reconstructive surgeon. Although many techniques have been established for the treatment of major scrotal defects, each technique has its own advantages and disadvantages in specific situations.Objective: The aim of this prospective study was to evaluate the outcome of thigh fascio-cutaneous flap for reconstruction of major scrotal loss with exposed testis.Methods: This prospective study was done for 5 years extending from January 2012 to December 2016. In this period we reconstructed major scrotal defects of eight patients with antero medial and pudendal thigh fascio-cutaneous flap in Burn and Plastic Surgery department, Khulna Medical College Hospital. Total eleven thigh fascio-cutaneous flaps were used for reconstruction of major scrotal defects.Results: The mean patient age was 41 years (range 24 to 62 years). The aetiology of scrotal loss was Fournier's gangrene in 4 cases and trauma in 4 cases. Three cases had bilateral and five cases had unilateral flap reconstruction. The flaps allowed sensate coverage and took well. Primary donor site closure obviated the need for skin grafts in most of the cases, Complications were flap tip necrosis (12.50%) and minor wound infection (12.50%) which were treated conservatively. Donor site scar was limited and acceptable. The flap had good aesthetic appearance except in one fatty patient where the flaps were bulky.Conclusion: The study concluded that thigh fascio-cutaneous flap is very reliable for coverage of major scrotal defects.Bang Med J (Khulna) 2017; 50 : 13-17

Egress and invasion machinery of malaria: an in-depth look into the structural and functional features of the flap dynamics of plasmepsin IX and X.

Plasmepsins, a family of aspartic proteases expressed by Plasmodium falciparum parasite, have been identified as key mediators in the onset of lethal malaria. Precedence has been placed on this family of enzymes due their essential role in the virulence of the parasite, thus highlighting their importance as novel drug targets. A previously published study by our group proposed a set of parameters used to define the flap motion of aspartic proteases. These parameters were used in the study of Plm I–V and focused on the flap flexibility as well as structural dynamics. Recent studies have highlighted the essential role played by Plm IX and X in egress and invasion of the malarial parasite. This study aims to close the gap on the latter family, investigating the flap dynamics of Plms IX and X. Molecular dynamics simulations demonstrated an “open and close” mechanism at the region of the catalytic site. Further computation of the dihedral angles at the catalytic region revealed tractability at both the flap tip and flexible loop. This structural versatility enhances the interaction of variant ligand sizes, in comparison to other Plm family members. The results obtained from this study signify the essential role of structural flap dynamics and its resultant effect on the binding landscapes of Plm IX and X. We believe that this unique structural mechanism may be integrated in the design and development of effective anti-malarial drugs.

Utility of superiorly based platysma myocutaneous flap for reconstruction of intraoral surgical defects: our experience.

Various surgical modalities have been advocated for the soft tissue reconstruction of oral cavity with variable results. This prospective study evaluates the utility of platysma myocutaneous flap (PMF) in the reconstruction of surgical defects followed by treatment of oral submucous fibrosis (OSMF) and oral squamous cell carcinoma (OSCC) in terms of healing and functional outcomes. In this prospective study, 47 patients with OSMF and 15 of OSCC were evaluated and selected for PMF reconstruction. OSCC was selected under T1N0M0 category only. Patients were operated under general anaesthesia followed by PMF grafting. In OSCC, ipsilateral and for OSMF, bilateral PMF was used. In 47 patients treated for OSMF, 46 were male and 1 female while 15 cases of OSCC, 10 were male and 5 females aged between 18 and 44years. Intraoperative mouth opening was achieved up to 48mm in OSMF followed by 42.5mm postoperatively after 2years. However, uneventful healing and acceptable scar on cervical region was noted in all the cases including OSCC. In OSMF, three cases of dehiscence, four partial necrosis at end of flap and in OSCC one case shows skin loss at flap and two partial necrosis at tip of flap and extraoral localised abscess at ipsilateral donor site in one case was noted. An uneventful healing, anatomical form and functional results were restored with acceptable scarring at donor site without any evidence of difficulty in neck movements were observed. The PMF is simple, versatile and could be valued as a reconstructive alternative, with interesting visual qualities. It is a good therapeutic alternative tool for reconstruction of the buccal mucosa, especially for small- and medium-sized defects between 2 and 4cm2 of the oral cavity.

Reconstruction of Facial-Cervical Scars With Pedicled Expanded Deltopectoral Flap.

The facial-cervical scars bring the suffering to the patients both physically and mentally. Choosing a proper donor soft tissue is always one of the critical issues, especially to Asian patients. Among the common used donor sites, the deltopectoral site was conceived as the most suitable donor tissue for the reconstruction in face and neck for its adjacent site and match in color and texture. There were 220 patients with facial-cervical scars reconstructed by the pedicled expanded deltopectoral flap between 2007 through 2015 in the authors' hospital. There are 4 stages, including tissue expansion, flap pedicled transfer, pedicle delaying, and pedicle division, for the reconstruction of the facial-cervical scars using the pedicled expanded deltopectoral flap. Good skin compliance, normal contours, and emotional expression were noted in all the patients after the reconstruction. However, there were complications including expander exposure, stretch marks, flap tip necrosis, and mild postoperative hypertrophic scars. The unpleasant skin wound or color caused by the complications was repaired by further treatments such as skin grafting and laser. In conclusion, the pedicled expanded deltopectoral flap is a reliable and excellent option for the reconstruction of the facial-cervical scars.

Reconstruction of Large Postburn Facial-Scalp Scars by Expanded Pedicled Deltopectoral Flap and Random Scalp Flap: Technique Improvements to Enlarge the Reconstructive Territory.

The scars of face and scalp caused by burning often show as 1 large facial-scalp scar. The deltopectoral flap was recognized as one of the first choices for the facial scar reconstruction. However, this flap cannot cross the level of zygomatic arch traditionally when it was transferred with pedicle. When the flap reconstructed the facial-scalp scars with expanded random scalp flap, another flap was often needed to reconstruct the remaining temple and forehead scars. The authors reviewed 24 patients of large facial-scalp scars reconstructed by expanded pedicled deltopectoral flap and scalp flap with several technique improvements. The seaming scar between the deltopectoral flap and scalp flap in the temple region formed the new hairline. The technique improvements included ligation of the perforating branches of the transverse cervical artery and thoracoacromial artery when dissecting the pocket, the partial bolster compressive dressing to the distal part of the flap and dividing the pedicle partly as a delaying procedure before dividing the pedicle completely. Good skin compliance, normal contours, and emotional expression were noted. There were complications including expander exposure in 3 patients, stretch marks in 5 patients, flap tip necrosis in 2 patients, and mild postoperative hypertrophic scars in 3 patients. In conclusion, the expanded pedicled deltopectoral flap can enlarge the reconstructive territory in face successfully with the technique improvements. The combination of the expanded pedicled deltopectoral flap and scalp flap is a reliable and excellent reconstructive option for large postburn facial-scalp scars.

Hinge action versus grip in translocation by RNA polymerase

ABSTRACTBased on molecular dynamics simulations and functional studies, a conformational mechanism is posited for forward translocation by RNA polymerase (RNAP). In a simulation of a ternary elongation complex, the clamp and downstream cleft were observed to close. Hinges within the bridge helix and trigger loop supported generation of translocation force against the RNA–DNA hybrid resulting in opening of the furthest upstream i−8 RNA–DNA bp, establishing conditions for RNAP sliding. The β flap tip helix and the most N-terminal β′ Zn finger engage the RNA, indicating a path of RNA threading out of the exit channel. Because the β flap tip connects to the RNAP active site through the β subunit double-Ψ–β-barrel and the associated sandwich barrel hybrid motif (also called the flap domain), the RNAP active site is coupled to the RNA exit channel and to the translocation of RNA–DNA. Using an exonuclease III assay to monitor translocation of RNAP elongation complexes, we show that K+ and Mg2+ and also an RNA 3′-OH or a 3′-H2 affect RNAP sliding. Because RNAP grip to template suggests a sticky translocation mechanism, and because grip is enhanced by increasing K+ and Mg2+concentration, biochemical assays are consistent with a conformational change that drives forward translocation as observed in simulations. Mutational analysis of the bridge helix indicates that 778-GARKGL-783 (Escherichia coli numbering) is a homeostatic hinge that undergoes multiple bends to compensate for complex conformational dynamics during phosphodiester bond formation and translocation.

Blood Congestion Can Be Rescued by Hemodilution in a Random-Pattern Skin Flap.

There is no standard method to ensure survival of random-pattern skin flaps. The authors developed a rat anemia model to observe survival of random-pattern skin flaps after blood transfusion and hemodilution. Anemia was induced by withdrawal of 35 percent blood volume followed by compensation with the same amount of blood (blood transfusion model) or plasma equivalent (normovolemic hemodilution). Control rats were subjected to a sham procedure. Subsequently, a random-pattern skin flap (1.5 × 6 cm) was elevated on the back of each rat. Physiologic assessments of flap vascularity/viability were performed using laser Doppler spectrophotometry before and after flap elevation. The normovolemic hemodilution group showed anemia (hemoglobin, 9.5 ± 0.8 g/dl) but less flow occlusion and greater flap survival (72.8 ± 8.6 percent) compared with control (57.4 ± 9.6 percent; p < 0.01) and blood transfusion (62.1 ± 6.5 percent; p < 0.089) groups. In control and blood transfusion groups but not the normovolemic hemodilution group, blood flow was decreased and relative quantity of hemoglobin was increased toward the flap tip, indicating congestion. In control and blood transfusion groups, blood flow and tissue oxygen saturation dropped after flap elevation, but recovered by day 7; congestion gradually improved by day 7. The authors determined that congestion promoted necrosis and hemodilution reduced microcirculatory occlusion and increased blood flow and oxygenation in skin flaps. It was suggested that perioperative hemodilution is superior to blood transfusion in any flap operations unless there is a critical systemic need for blood transfusion.

Abstract 6. The Anatomic Implications of Utilizing Cannula Lipodissection and Avoiding Platysmaplasty in the Tumescent Facelift: A Clinical and Cadaveric Study

Purpose: The tumescent facelift utilizes Saldanha’s concept of cannula lipodissection, as opposed to wide undermining, to recruit soft tissue while preserving perforating neurovascular branches. The information herein is a clinical and cadaveric study examining the senior author’s technique for tumescent lipodissection in rhytidectomy. Methods: From 2005–2016, 1,000 consecutive patients underwent rhytidectomy by the senior author (LPB). In addition to implementing cannula lipodissection, the senior author avoids routine anterior platysmaplasty as it was observed to limit jowl excursion of the lower face. In an attempt to validate the abovementioned approach (developed from clinical observation), a cadaveric study was performed on five fresh tissue cadavers. Post-auricular skin excursion was measured following lipodissection (cannula only) and then measured again after traditional wide undermining. Next, SMAS flap and jowl excursion were measured with and without anterior platysmaplasty. A force gauge was utilized to ensure that equivalent force was applied during all comparisons of skin and SMAS excursion. Results: Cannula lipodissection resulted in a mean skin excursion of 41.9mm. There was no significant difference in skin excursion compared to wide undermining (41.9 versus 42.1mm; p=0.785). Jowl position, in reference to the mandibular border, was significantly lower following anterior plastysmaplasty (18.3 versus -3.4mm; p=0.005). Anterior platsymaplasty; however, did not adversely affect the excursion at the tip of the high lateral SMAS flap (39.3 versus 37.9mm; p=0.644) Conclusion: Cannula lipodissection results in equivalent skin recruitment in comparison to wide undermining. Routine anterior platysmaplasty may compromise results by inhibiting jowl excursion.

Popliteal fossa reconstruction with a medial sural artery perforator free flap using the medial sural vessel as the recipient

Background: Reconstruction of the popliteal fossa using a free flap is challenging. Therefore, to facilitate easier free flap reconstruction of the popliteal fossa, we use a medial sural artery perforator (MSAP) free flap with a medial sural vessel as the recipient vessel, as it provides several advantages based on many reports.Methods: This report describes the authors’ experience and outcomes with this technique. Between October 2010 and January 2015, 10 patients with medium-sized defects in their popliteal fossa underwent MSAP free flap reconstruction using the medial sural vessel as the recipient vessel. The flap size and thickness were evaluated, as well as the pedicle length, for each case.Results: The skin flap sizes ranged from 60–112 cm2. The average flap thickness was 6 mm (range = 4–8 mm), and the average pedicle length was 7.5 cm (range = 6–9 cm). Full flap survival was observed in nine cases, and flap tip necrosis was observed in one case during a mean follow-up of 15 months (range = 3–36 months). MSAP free flap reconstruction was performed for moderate-sized defects in the popliteal fossa, using the medial sural vessel as the recipient vessel.Conclusion: The obvious advantages of this technique included simple vascular anastomosis (minimal size discrepancy), no intraoperative position changes, and good aesthetic outcomes (replacing like with like).