Medial Perforant Research Articles

Comparison Between Free Anterolateral Thigh Flap and Free Medial Sural Artery Perforator Flap in Reconstruction of Post Traumatic Soft Tissue Defects of the Dorsum of the Foot

Abstract Background: The objective of this study is to compare between the free anterolateral thigh flap and free medial sural artery perforator flap in reconstruction of post traumatic soft tissue defects of dorsum of the foot as regard the function, the aesthetic outcome, the complications and the patient satisfaction.Method: The study was conducted on 40 patients with post traumatic soft tissue defects of the dorsum of the foot between August 2018 and August 2019. Patients were allocated randomly into two groups. In group1 (20 patients), the defect was reconstructed with free anterolateral thigh perforator flap. In group 2 (20 patients), reconstruction was done by free medial sural artery perforator flap.Result: In group 1 (ALT flap), Complete flap survival was achieved in all cases. Thirteen patients required secondary debulking procedures and scar revisions.In group 2 (MSAP Flap), Complete flap survival was achieved in 17 cases with one flap totally lost and two flaps had distal necrosis. One patient needed scar revision and another patient needed flap advancement.Conclusion: MSAP flap is good alternative in soft tissue reconstruction of the dorsum of the foot. It has many advantages: it is thin, pliable, fitted to normal footwear, less hairy and there is no need for secondary procedures in most cases. ALT flap is better than MSAP flap in larger defects coverage but may need secondary debulking procedures or primary thinning at the time of reconstruction.

Free-style Approach to the Pedicled Lower Medial Thigh Perforator Flap.

Summary:Soft tissue reconstruction around joints such as the knee requires a few additional considerations compared with other regions. The overlying skin must be pliable, with adequate distensibility to maintain the range of motion as a hinge joint, and ideally be replaced with “like-for-like” tissue to restore its delicate contour. The advent of perforator flaps has provided reconstructive surgeons with thin, pliable flaps conferring superior aesthetic results, good preservation of joint range of motion, and less donor site morbidity. Utilizing locoregional options also allows replacement with “like-for-like.” We retrospectively reviewed lower medial thigh perforator flaps performed for traumatic and debrided infected knee wounds, using a free-style approach to flap harvest. The described technique was found to be reliable, with consistent anatomy. All flaps survived and successfully covered small- to medium-sized critical defects in healthy individuals and those with multiple comorbidities.

The medial sural artery perforator pedicle propeller flap for lower middle-third anterior tibial soft tissue defect reconstruction: Case report and literature review

Abstract Lower extremity reconstruction still issues a challenge for plastic surgeons. The medial sural artery perforator (MSAP) flap has been reported for use to reconstruct the defects of the knee and proximal-third leg defects in many papers. But there is a few papers that described the technique of using this flap for reaching the middle third led defects. The authors report the first using MSAP propeller flap in Vietnam to cover the defect in a 45-year-old female patient who suffered from chronic ulcer with bone exposure over the middle third anterior tibial and evaluate the result of 4 months post-op. Keywords: Lower extremities defects reconstruction, perforator flap, medial sural artery perforator flap, propeller flap.

Medial sural artery perforator flap—indications, tips and pitfalls

Medial sural artery perforator flap—indications, tips and pitfalls

Comparison between Free Anterolateral Thigh Flap and Free Medial Sural Artery Perforator Flap in Reconstruction of Post Traumatic Soft Tissue Defects of Dorsum of the Foot

Background: The objective of this study was to compare the pliability, the function, aesthetic outcome, complications and patient satisfaction between free anterolateral thigh flap and free medial sural artery perforator flap in reconstruction of post traumatic soft tissue defects of dorsum of the foot. Method: The study was conducted on forty patients with post traumatic soft tissue defects of the dorsum of the foot between August 2018 and August 2019. Patients were divided randomly into two groups. In group1 (20 patients), the defects were reconstructed with free anterolateral thigh perforator flap. In group 2 (20 patients), reconstruction was done by free medial sural artery perforator flap. Result: In group 1 (ALT flap), Complete flap survival was achieved in 100% of cases. Thirteen patients required secondary debulking procedures and scar revisions. In group 2 (MSAP Flap), Complete flap survival was achieved in 85% with one flap totally lost and two flaps had distal necrosis. One patient needed scar revision and another patient needed flap advancement. Conclusion: MSAP flap is superior to ALT flap. It has many advantages: it is thin, pliable, fitted to normal footwear, less hairy and there is no need for secondary procedures in most cases.

Leaving the perfusion zones? Individualized flap design in 100 free DIEP and ms-TRAM flaps for autologous breast reconstruction using indocyanine green angiography

BackgroundThere is still no consensus regarding the ideal zoning in abdominal-based autologous breast reconstruction using free DIEP or ms-TRAM flaps. In particular, the perfusion pattern of the flap according to the number of perforators used and their location remains controversial. In this study, the perfusion of free DIEP and ms-TRAM flaps is assessed intraoperatively and analyzed with regard to different perfusion patterns. MethodsA retrospective analysis of 100 free flaps for breast reconstruction was performed. Following complete flap harvest, we used indocyanine green angiography for perfusion analysis. By applying two different contour levels, DIEP flaps with lateral or medial perforators and ms-TRAM flaps were assessed for their respective perfusion patterns. ResultsNo statistically significant differences were found in the size of the perfusion area between the different flap types when applying the contour level of 20% (p >0.05). For the contour level of 30%, however, statistically significant differences were found between DIEP flaps with medially or laterally located perforators (p = 0.038). Laterally or medially located perforators in DIEP flaps showed no significant differences in their ability to cross the midline (contour level 20%, p = 0.068; contour level 30%, p = 0.058). ConclusionConsidering the variability of the perfusion of the abdominal wall and the high sensitivity of indocyanine green angiography for their detection, the abdominal zonings play a minor role. By using intraoperative indocyanine green angiography, a precise and patient-specific free flap surgery for autologous breast reconstruction is possible independent of perforator location.

Cover Image, Volume 31, Issue 9

The cover image is based on the Research Article Preferential frequency-dependent induction of synaptic depression by the lateral perforant path and of synaptic potentiation by the medial perforant path inputs to the dentate gyrus by Jens Collitti-Klausnitzer et al., https://doi.org/10.1002/hipo.23338.

Correction of eating disorders in patients with oral and oropharyngeal cancer after reconstructive plastic surgery

The study objective – to evaluate the feasibility of correcting eating disorders in patients undergoing surgery for oral and oropharyngeal cancers using various reconstructive techniques to restore postoperative defects.Materials and methods. Between 2012 and 2019, a total of 56 patients with stage II–IV oral and oropharyngeal cancer underwent reconstructive surgery after either hemiglossectomy or glossectomy. The patients ranged in age from 26 to 70 years. The patients were divided into two groups. Group I consisted of 36 (64.3 %) patients who underwent tongue reconstruction using rotation flaps. For reconstruction of hemiglossectomy defects, a chin flap was used, and for reconstruction of glossectomy defects, a pectoral flap was used. Group II comprised 20 (35.7 %) patients who underwent tongue reconstruction using free revascularized flaps. For the tongue reconstruction after hemiglossectomy, the radial flap, medial sural perforator flap and fasciocutaneous anterolateral thigh flap were used. For the tongue reconstruction after glossectomy, the fasciocutaneous anterolateral thigh flap was used. The acts of chewing and swallowing were restored during speech rehabilitation due to the activation and coordination of the work of the muscles of the cheeks, lips, soft palate, pharynx, and the reconstructed tongue. Eating disorders were assessed by interviewing patients. A comparative analysis of eating disorders included mobility and coordination of facial muscles and reconstructed tongue, increased sensitive in the oral cavity, the presence of aspiration and nasal regurgitation, and subjective difficulties of patients. The time before the start of rehabilitation and its duration were taken into account. Patients were interviewed before the start of the combined treatment, at the beginning and after the completion of rehabilitation.Results. After the completion of rehabilitation, all patients received food by the oral route. The best outcomes were achieved in group 2a patients, who underwent tongue reconstruction with free revascularized flaps. This group of patients had a lower percentage of the asymmetry of facial muscles and limited mobility of the tongue compared to other groups of patients.In the subgroups of patients undergoing glosssectomy, most of the studied parameters did not have statistically significant differences in values. However, it should be noted that in group 2b, the period from the date of surgical treatment to the beginning of rehabilitation was significantly longer than in group 1b.Conclusion. The use of the microvascular surgical techniques using various donor flaps creates the basis for a more complete functional recovery and expands the rehabilitation potential of patients after surgical treatment of oral and oropharyngeal cancer.

Environmental Enrichment Rescues Endocannabinoid-Dependent Synaptic Plasticity Lost in Young Adult Male Mice after Ethanol Exposure during Adolescence.

Binge drinking (BD) is a serious health concern in adolescents as high ethanol (EtOH) consumption can have cognitive sequelae later in life. Remarkably, an enriched environment (EE) in adulthood significantly recovers memory in mice after adolescent BD, and the endocannabinoid, 2-arachydonoyl-glycerol (2-AG), rescues synaptic plasticity and memory impaired in adult rodents upon adolescent EtOH intake. However, the mechanisms by which EE improves memory are unknown. We investigated this in adolescent male C57BL/6J mice exposed to a drinking in the dark (DID) procedure four days per week for a duration of 4 weeks. After DID, the mice were nurtured under an EE for 2 weeks and were subjected to the Barnes Maze Test performed the last 5 days of withdrawal. The EE rescued memory and restored the EtOH-disrupted endocannabinoid (eCB)-dependent excitatory long-term depression at the dentate medial perforant path synapses (MPP-LTD). This recovery was dependent on both the cannabinoid CB1 receptor and group I metabotropic glutamate receptors (mGluRs) and required 2-AG. Also, the EE had a positive effect on mice exposed to water through the transient receptor potential vanilloid 1 (TRPV1) and anandamide (AEA)-dependent MPP long-term potentiation (MPP-LTP). Taken together, EE positively impacts different forms of excitatory synaptic plasticity in water- and EtOH-exposed brains.

Lack of the Transient Receptor Potential Vanilloid 1 Shifts Cannabinoid-Dependent Excitatory Synaptic Plasticity in the Dentate Gyrus of the Mouse Brain Hippocampus.

The transient receptor potential vanilloid 1 (TRPV1) participates in synaptic functions in the brain. In the dentate gyrus, post-synaptic TRPV1 in the granule cell (GC) dendritic spines mediates a type of long-term depression (LTD) of the excitatory medial perforant path (MPP) synapses independent of pre-synaptic cannabinoid CB1 receptors. As CB1 receptors also mediate LTD at these synapses, both CB1 and TRPV1 might be influencing the activity of each other acting from opposite synaptic sites. We tested this hypothesis in the MPP–GC synapses of mice lacking TRPV1 (TRPV1-/-). Unlike wild-type (WT) mice, low-frequency stimulation (10 min at 10 Hz) of TRPV1-/- MPP fibers elicited a form of long-term potentiation (LTP) that was dependent on (1) CB1 receptors, (2) the endocannabinoid 2-arachidonoylglycerol (2-AG), (3) rearrangement of actin filaments, and (4) nitric oxide signaling. These functional changes were associated with an increase in the maximum binding efficacy of guanosine-5′-O-(3-[35S]thiotriphosphate) ([35S]GTPγS) stimulated by the CB1 receptor agonist CP 55,940, and a significant decrease in receptor basal activation in the TRPV1-/- hippocampus. Finally, TRPV1-/- hippocampal synaptosomes showed an augmented level of the guanine nucleotide-binding (G) Gαi1, Gαi2, and Gαi3 protein alpha subunits. Altogether, the lack of TRPV1 modifies CB1 receptor signaling in the dentate gyrus and causes the shift from CB1 receptor-mediated LTD to LTP at the MPP–GC synapses.

P-136 Colour Flow Doppler vascular assessment before Medial Sural Artery Perforator (MSAP) free flaps: a prospective clinical study

P-136 Colour Flow Doppler vascular assessment before Medial Sural Artery Perforator (MSAP) free flaps: a prospective clinical study

Prolonged development of long-term potentiation at lateral entorhinal cortex synapses onto adult-born neurons.

Critical period plasticity at adult-born neuron synapses is widely believed to contribute to the learning and memory functions of the hippocampus. Experience regulates circuit integration and for a transient interval, until cells are ~6 weeks old, new neurons display enhanced long-term potentiation (LTP) at afferent and efferent synapses. Since neurogenesis declines substantially with age, this raises questions about the extent of lasting plasticity offered by adult-born neurons. Notably, however, the hippocampus receives sensory information from two major cortical pathways. Broadly speaking, the medial entorhinal cortex conveys spatial information to the hippocampus via the medial perforant path (MPP), and the lateral entorhinal cortex, via the lateral perforant path (LPP), codes for the cues and items that make experiences unique. While enhanced critical period plasticity at MPP synapses is relatively well characterized, no studies have examined long-term plasticity at LPP synapses onto adult-born neurons, even though the lateral entorhinal cortex is uniquely vulnerable to aging and Alzheimer's pathology. We therefore investigated LTP at LPP inputs both within (4-6 weeks) and beyond (8+ weeks) the traditional critical period. At immature stages, adult-born neurons did not undergo significant LTP at LPP synapses, and often displayed long-term depression after theta burst stimulation. However, over the course of 3-4 months, adult-born neurons displayed increasingly greater amounts of LTP. Analyses of short-term plasticity point towards a presynaptic mechanism, where transmitter release probability declines as cells mature, providing a greater dynamic range for strengthening synapses. Collectively, our findings identify a novel form of new neuron plasticity that develops over an extended interval, and may therefore be relevant for maintaining cognitive function in aging.

Preferential frequency-dependent induction of synaptic depression by the lateral perforant path and of synaptic potentiation by the medial perforant path inputs to the dentate gyrus.

The encoding of spatial representations is enabled by synaptic plasticity. The entorhinal cortex sends information to the hippocampus via the lateral (LPP) and medial perforant (MPP) paths that transfer egocentric item-related and allocentric spatial information, respectively. To what extent LPP and MPP information-relay results in different homosynaptic synaptic plasticity responses is unclear. We examined the frequency dependency (at 1, 5, 10, 50, 100, 200 Hz) of long-term potentiation (LTP) and long-term depression (LTD) at MPP and LPP synapses in the dentate gyrus (DG) of freely behaving adult rats. We report that whereas the MPP-DG synapses exhibit a predisposition toward the expression of LTP, LPP-DG synapses prefer to express synaptic depression. The divergence of synaptic plasticity responses is most prominent at afferent frequencies of 5, 100,Hz and 200 Hz. Priming with 10 or 50 Hz significantly modified the subsequent plasticity response in a frequency-dependent manner, but failed to change the preferred direction of change in synaptic strength of MPP and LPP synapses. Evaluation of the expression of GluN1, GluN2A, or GluN2B subunits of the NMDA receptor revealed equivalent expression in the outer and middle thirds of the molecular layer where LPP and MPP inputs convene, respectively, thus excluding NMDA receptors as a substrate for the frequency-dependent differences in bidirectional plasticity. These findings demonstrate that the LPP and MPP inputs to the DG enable differentiated and distinct forms of synaptic plasticity in response to the same afferent frequencies. Effects are extremely robust and resilient to metaplastic priming. These properties may support the functional differentiation of allocentric and item information provided to the DG by the MPP and LPP, respectively, that has been proposed by others. We propose that allocentric spatial information, conveyed by the MPP is encoded through hippocampal LTP in a designated synaptic network. This network is refined and optimized to include egocentric contextual information through LTD triggered by LPP inputs.

Hippocampal subfield‐specific Homer1a expression is triggered by learning‐facilitated long‐term potentiation and long‐term depression at medial perforant path synapses

Learning about general aspects, or content details, of space results in differentiated neuronal information encoding within the proximodistal axis of the hippocampus. These processes are tightly linked to long-term potentiation (LTP) and long-term depression (LTD). Here, we explored the precise sites of encoding of synaptic plasticity in the hippocampus that are mediated by information throughput from the perforant path. We assessed nuclear Homer1a-expression that was triggered by electrophysiological induction of short and long forms of hippocampal synaptic plasticity, and compared it to Homer1a-expression that was triggered by LTP and LTD enabled by different forms of spatial learning. Plasticity responses were induced by patterned stimulation of the perforant path and were recorded in the dentate gyrus (DG) of freely behaving rats. We used fluorescence in situ hybridization to detect experience-dependent nuclear encoding of Homer1a in proximodistal hippocampal subfields. Induction of neither STP nor STD resulted in immediate early gene (IEG) encoding. Electrophysiological induction of robust LTP, or LTD, resulted in highly significant and widespread induction of nuclear Homer1a in all hippocampal subfields. LTP that was facilitated by novel spatial exploration triggered similar widespread Homer1a-expression. The coupling of synaptic depression with the exploration of a novel configuration of landmarks resulted in localized IEG expression in the proximal CA3 region and the lower (infrapyramidal) blade of the DG. Our findings support that synaptic plasticity induction via perforant path inputs promotes widespread hippocampal information encoding. Furthermore, novel spatial exploration promotes the selection of a hippocampal neuronal network by means of LTP that is distributed in an experience-dependent manner across all hippocampus subfields. This network may be modified during spatial content learning by LTD in specific hippocampal subfields. Thus, long-term plasticity-inducing events result in IEG expression that supports establishment and/or restructuring of neuronal networks that are necessary for long-term information storage.

Iliac Screw Fixation Revisited: Improved Clinical and Radiologic Outcomes Using a Modified Iliac Screw Fixation Technique.

A retrospective study. To describe the modified iliac screw (mILS) technique and compare it to other spinopelvic fixation techniques in terms of wound healing complications, hardware prominence, and failure. The traditional entry point of an iliac screw often causes postoperative gluteal pain from the prominent screw head. The use of an offset connector also adds a point of weakness to the construct. By choosing a different screw entry point offset connectors can be avoided, and the screw head itself is less prominent, thereby reducing postoperative discomfort. A retrospective analysis was performed of adult patients undergoing lumbopelvic fixation (LPF) between January 2014 and June 2019. Patients were grouped into 1 of 3 groups based on the technique of pelvic fixation: S2 alar-iliac (S2AI) screw, traditional iliac screw (tILS), and mILS. The primary outcome parameter was the minimal distance from screw head to skin. Secondary outcome parameters were instrumentation loosening/failure, adjacent level fractures, pseudoarthrosis, and medial or lateral iliac screw perforation. A total of 190 patients undergoing LPF were included in the following 3 groups: mILS group (n=113), tILS group (n=40), and S2AI group (n=37). The mean minimal distance from screw head to skin in the mILS group was 31.3 mm compared with 23.7 mm in the tILS group (P<0.00199). No statistically significant differences were found when comparing the 3 groups with respect to complications. The mILS group did not show any cases of prominent instrumentation and had the lowest rate of instrumentation failure. The mILS technique is an acceptable alternative for LPF, offering the benefits of iliac screw fixation while avoiding offset connectors and screw prominence complications associated with tILS. Level III.

Research progress of clinical application of medial sural artery perforator flap

To review the research progress of the clinical application of the medial sural artery perforator flap (MSAPF). The relevant domestic and abroad literature on the clinical application of MSAPF was extensively consulted, and the research progress were summarized and analyzed in aspect of its definition, anatomical characteristics, clinical application, surgical resection and improvement, and advantages and disadvantages of flaps, etc. MSAPF has the advantages of relatively constant anatomical position, thin flap texture, long vascular pedicle, large vessel diameter, no sacrifice of main blood vessels, concealed donor site, no hair, and fewer complications; it can carry nerves, tendons, and muscles to construct chimeric flaps to repair three-dimensional wounds; and can also repair wounds with high aesthetic and functional requirements such as hand, foot and ankle, head and neck, etc. The MSAPF is a versatile, various forms, functional diversification, and three-dimensional flap donor site with various application forms and ideal repair effectiveness.

Reconstruction of thumb defects with medial sural artery perforator flap: case series.

BackgroundDigital defect is one of the most common types of emergency hand injuries. Plastic surgeons continue to search for a better method to repair digital defects, especially those of the thumb. The medial sural artery perforator (MSAP) flap has been widely used as a popular method for limb and head reconstruction. Our findings have led us to advocate the use of free medial sural artery perforator flap to repair large thumb defects.MethodsFrom July 2010 to July 2013, we used free MSAP flaps to resurface large defects of 9 thumbs in 9 clinical cases. There were 6 men and 3 women among the participants, aged 21–49 years (average age: 37.6 years). Flap sizes varied from 2 cm × 3 cm to 3 cm × 6 cm. Perforators of all flaps were accurately located by color Doppler detection.ResultsAccording to color Doppler detection, the distance from the popliteal crease to the points where first/second perforator pierced the deep fascia was 10.1±1.1/15.2±0.8 cm. The distance from the midline to the first/second perforator was 2.8±0.8/3.5±0.5 cm. A total of nine flaps fully survived. All defects of the nine thumbs were adequately resurfaced. Postoperative follow-up conducted at 12–24 months revealed satisfaction in both cosmetic and function results.ConclusionsThe MSAP flap, which can be easily harvested and well thinned, is an ideal choice to repair thumb defects. Accurate location of the perforator by Doppler detection ensures the surgical success, and minimizes injury to the donor site.

The chimeric medial sural artery perforator flap as the ideal for partial tongue reconstruction: A case series and technical refinements

The medial sural artery perforator free flap (MSAP) has gained increasing popularity in head and neck reconstruction. Its slightly bulkier nature than the radial forearm flap, combined with negligible donor site morbidity, makes it an ideal candidate for the reconstruction of partial glossectomy defects. The ability to harvest the MSAP as a chimeric flap with a portion of the medial gastrocnemius muscle gives it greater flexibility in soft tissue reconstruction. A retrospective study of patients with partial glossectomy defects reconstructed using the MSAP by a single surgeon was performed. Perioperative data, donor and recipient site characteristics, complications, and outcomes were analyzed. A video is included to show technical points for the harvest of the flap. A total of 10 patients were included. The average age was 59.1 years, with a mean of 43.5% of the tongue resected. All flaps survived, with no major complications. At follow-up, the patients had regained an average of 86.5% of original speech, with none requiring NG feeding. The average MSAP skin flap thickness was 7.8 mm, with 6 flaps being harvested as chimeric fasciocutaneous muscle flaps. Five flaps incorporated 2 perforators. Two case examples are presented. The chimeric MSAP perforator allows for more robust partial glossectomy reconstruction with improved postoperative functional outcomes. It should be considered as the workhorse flap for partial tongue reconstruction.

Medial Sural Perforator “Nerve through Flap”: Anatomical Study and Clinical Application

Background: Nerve recovery after a complex trauma is affected by many factors and a poorly vascularized bed is often the cause of failure and perineural scar. Many techniques have been devised to avoid this problem and the possibility to transfer a nerve with a surrounding viable sliding tissue could help in this purpose; Methods: We performed an anatomic study on 8 injected specimens to investigate the possibility to raise a medial sural artery perforator (MSAP) flap including the sural nerve within its vascularized sheath; Results: In anatomic specimens, a visible direct nerve vascularization was present in 57% of legs (8 out of 14). In 43% a vascular network was visible in the fascia layer. There were no vascular anomalies. In one patient the MSAP flap was raised including the sural nerve with its proximal tibial and peroneal components within the deep sheath. The tibial and peroneal component of the sural nerve were anastomized independently with the common digital nerve of 4th and 5th fingers and with the collateral nerve for the ulnar aspect of the 5th. After 9 months, the patient showed an improving nerve function both clinically and electromyographically without any problem due to nerve adherence; Conclusions: Given the still debated advantage of a vascularized nerve graft versus a non-vascularized one, this flap could be useful in those cases of composite wounds with nerve lesions acting as a “nerve through flap”, in order to reduce nerve adherence with a viable surrounding gliding tissue.

Exploration on clinical treatment of incisional wound infection after orthopedic internal fixation for lower extremity joint injuries

Exploration on clinical treatment of incisional wound infection after orthopedic internal fixation for lower extremity joint injuries