Buried Flaps Research Articles

NIRO200NX: Reliable Monitoring System for Buried Deep Inferior Epigastric Perforator Flap.

The deep inferior epigastric perforator (DIEP) flap is a useful tool for breast reconstruction and tends to be transferred into the breast envelope as the buried flap from an aesthetic point of view. However, it is difficult to monitor the blood flow in the buried DIEP flap after reconstructive microsurgery. Near-infrared spectroscopy devices have recently been used for monitoring the blood flow of various organs. NIRO200NX (Hamamatsu Photonics) continuously measures the tissue oxygen index (TOI) and quickly reflects changes in flap blood flow. In this study, we investigated whether and how much the NIRO200NX applies to monitoring the blood flow of the buried flap. We included 156 patients who underwent breast reconstruction using a DIEP flap from October 2013 to May 2022, comprising 57 exposed and 99 buried-type DIEP flap cases. We measured TOI using NIRO200NX, in combination with conventional evaluation methods, including color check, pinprick test, and Doppler sound. A criterion of TOI 50 gave the best evaluations. All the 57 exposed-type flap cases showed no false evaluations, and NIRO200NX performed precise judgment. In 99 buried-type flap cases, NIRO200NX correctly evaluated 96 cases. For those buried-type cases, we found only two false-positive and one false-negative case. The misjudgments by NIRO200NX were likely caused by hematoma. We propose NIRO200NX as a reliable device for monitoring the blood flow of the DIEP flap and predicting the outcomes of breast reconstruction by the DIEP flap transfer.

No Skin Paddle, No Problem: Burying Deep Inferior Epigastric Artery Flaps in the Immediate Setting is Safe in Select Patient Populations.

In appropriately selected patients, it may be possible to fully bury breast free flaps deep to the mastectomy skin flaps. Because this practice forgoes the incorporation of a monitoring skin paddle for the flap, and thus limits the ability for physical exam, it may be associated with an increased risk of flap loss or other perfusion-related complications, such as fat necrosis. We hypothesized that fully de-epithelialized breast free flaps were not associated with an increased complication rate and reduced the need for future revision surgery. A single-institution retrospective review of 206 deep inferior epigastric artery (DIEP) flaps in 142 patients was performed between June 2016 and September 2021. Flaps were grouped into buried or nonburied categories based on the absence or presence of a monitoring paddle. Patient-reported outcomes were assessed postoperatively using the BREAST-Q breast reconstruction module. Electronic medical record data included demographics, comorbidities, flap characteristics, complications, and revision surgery. The buried flap patients (N = 46) had a lower median body mass index (26.9 vs 30.3, p = 0.04) and a lower rate of hypertension (19.5 vs. 37.5%, p = 0.04) compared with nonburied flap patients (N = 160). Burying flaps was more likely to be adopted in skin-sparing mastectomy or nipple-sparing mastectomy (p = 0.001) and in an immediate or a delayed-immediate fashion (p = 0.009). There was one flap loss in the nonburied group; complication rates were similar. There was a significantly greater revision rate in the nonburied flap patients (92 vs. 70%; p = 0.002). Buried flap patients exhibited a greater satisfaction with breasts (84.5 ± 13.4 vs. 73.9 ± 21.4; p = 0.04) and sexual satisfaction (73.1 ± 22.4 vs. 53.7 ± 29.7; p = 0.01) compared with nonburied flap patients. Burying breast free flaps in appropriately selected patients does not appear to have a higher complication rate when compared with flaps with an externalized monitoring paddle. Furthermore, this modification may be associated with a better immediate aesthetic outcome and improved patient satisfaction, as evidenced by a lower rate of revision surgery and superior BREAST-Q scores among buried DIEP flaps.

Complex breast reconstruction using bilateral profunda artery perforator-free-flaps in a resource-limited setting: a case report

Interestingly, the current shift in mastectomy patterns and advances in reconstruction techniques have contributed to an increasing number of patients requesting breast reconstruction postmastectomy every year. Depending on available expertise, patients can access breast reconstruction options (immediate or delayed), autologous, or implant-based. We present a case of a 36-year-old female patient 5 years into remission, having undergone mastectomy for invasive ductal carcinoma of the right breast and now preferred risk reduction surgery (prophylactic mastectomy) of her left unaffected breast with immediate reconstruction. The microsurgical technique utilized bilateral profunda artery perforator flaps from both thighs for (immediate and delayed) breast reconstruction. In our scenario, the authors had an unfavorable outcome on the side of delayed breast reconstruction (right) with a venous insufficiency diagnosis leading to unilateral complete flap loss, which was subsequently debrided and reconstructed with an obliquely-oriented pedicled Latissimus dorsi flap. In contrast, following risk reduction surgery and immediate reconstruction on the left side, the buried flap was a complete success, with the free nipple graft doing well postoperatively.

Near-Infrared Spectroscopy for Continuous Noninvasive Monitoring of Free Flap in Head and Neck Reconstruction: Systematic Review of the Literature and Personal Experience.

Buried free flaps represent a reconstructive challenge concerning monitoring of vitality, which is fundamental for an early detection of flap failure and prompt surgical salvage. Many flap monitoring techniques have been developed over time, and there is still no consensus concerning the best monitoring technique for buried reconstructions. We performed a systematic review of the literature on NIRS monitoring for head and neck free flaps. Moreover, we presented a case of orbital reconstruction through a buried free myo-fascial anterolateral tight flap (ALTF) in which postoperative monitoring was performed by means of NIRS. Four studies were included with a total of 200 monitored head and neck free flap reconstructions. Flap survival was reported in 96.5% of studies (n = 193/200) with a 3.5% of total flap failure rate (n = 7/200). We monitored the buried myo-fascial ALTF for 7 post-operative days measuring a regional oxygen saturation (rSO2) ranging from 55% to 72% (mean = 66%). This device appeared to be an efficient choice for monitoring buried flaps, thanks to its ability to measure tissue perfusion deep under the skin, to the continuous availability of recorded data on the monitor, and to its low impact on the patient. Further prospective studies are advised in order to standardize this monitoring technique and define warning values.

Postoperative free flap monitoring in reconstructive surgery-man or machine?

Free tissue transfer is widely used for the reconstruction of complex tissue defects. The survival of free flaps depends on the patency and integrity of the microvascular anastomosis. Accordingly, the early detection of vascular comprise and prompt intervention are indispensable to increase flap survival rates. Such monitoring strategies are commonly integrated into the perioperative algorithm, with clinical examination still being considered the gold standard for routine free flap monitoring. Despite its widespread acceptance as state of the art, the clinical examination also has its pitfalls, such as the limited applicability in buried flaps and the risk of poor interrater agreement due to inconsistent flap (failure) appearances. To compensate for these shortcomings, a plethora of alternative monitoring tools have been proposed in recent years, each of them with inherent strengths and limitations. Given the ongoing demographic change, the number of older patients requiring free flap reconstruction, e.g., after cancer resection, is rising. Yet, age-related morphologic changes may complicate the free flap evaluation in elderly patients and delay the prompt detection of clinical signs of flap compromise. In this review, we provide an overview of currently available and employed methods for free flap monitoring, with a special focus on elderly patients and how senescence may impact standard free flap monitoring strategies.

Monitoring Buried Flap in Pharyngeal Defect Reconstruction.

Laryngopharyngeal resection with permanent tracheostoma for advanced laryngeal malignancy is a reconstructive challenge. A thin fasciocutaneous flap, such as a radial artery forearm flap, is best suited to restore the continuity of partial pharyngeal defects. However, the flap skin surface forms the lining precluding its monitoring. Postoperative monitoring of these buried flaps has not been satisfactory, and various described methods include direct visualization by an endoscope, implantable Doppler, manipulation of skin paddle, external skin bridge segment, venous flow through flap, and so on.[1] [2] [3] [4] Each of these calls for careful planning, design, and execution.

An Algorithm for Selecting Buoy Skin Paddle Design for Flap Monitoring in Total Autologous Breast Reconstruction After Nipple-Sparing Mastectomy.

Introduction Monitoring buried flaps in reconstructive breast surgery is challenging, and the ideal technique is controversial. Established options include leaving an exterior ("buoy" or "sentinel") skin paddle versus invasive implantable devices to avoid removing the paddle later. Technical modifications and an algorithm for strategic skin paddle positioning to circumvent this while avoiding complex monitoring equipment are proposed. Patients and methods Patients in whom buoy skin paddles were utilized for breast flap monitoring by a single surgeon were reviewed. Indications, demographic details, precise monitoring paddle location, and flap outcomes were evaluated. An algorithm and classification system were then formulated. Results Thirteen buoy skin paddles were utilized in seven patients (mean age: 43.5 years; range: 31-65) to monitor reconstructive flaps performed for risk-reducing mastectomies (four patients and seven breasts), therapeutic mastectomy (one breast), and revision surgery (three patients and five breasts). The flaps comprised seven deep inferior epigastric artery perforators (DIEPs), four superficial inferior epigastric arteries (SIEAs), and two pedicled latissimus dorsi (LDs) (mean free flap weight: 809 g; average mastectomy weight (n = 10 breasts): 467 g; range: 248-864). The skin paddles were located horizontally along the inframammary crease or vertically inferior to the nipple-areola or both. All flap transfers were successful with no re-explorations. All patients declined the monitoring paddle excision, and none have requested breast mound revision for poor cosmesis or contour deformities. Conclusion Vertical and horizontal skin paddles proved reliable for buried flap monitoring without recourse to invasive and expensive equipment. When designed appropriately, they do not require revision surgery. An algorithmic classification of skin paddle location to enable this is proposed.

3D color doppler ultrasound for postoperative monitoring of vascularized lymph node flaps.

Vascularized lymph node transfer (VLNT) is arelatively well-established microsurgical treatment for lymphedema that is especially beneficial for advanced cases in which lymphovenous anastomosis is not indicated due to lymphatic vessel sclerosis. When VLNT is performed without askin paddle, such as aburied flap, the possibilities for postoperative monitoring are limited. The aim of our study was to evaluate the use of ultra-high-frequency color Doppler ultrasound with 3D reconstruction in apedicled axillary lymph node flap. Flaps were elevated in 15 Wistar rats based on the lateral thoracic vessels. We preserved the axillary vessels to maintain the rats' mobility and comfort. The rats were divided into three groups as follows: Group A, arterial ischemia; group B, venous occlusion; and group C, healthy. Ultrasound and color Doppler scan images revealed clear information on flap morphology changes and pathology if it was present. Surprisingly, we detected venous flow in group Arats, supporting the pump theory and venous lymph node flap concept. We conclude that 3D color Doppler ultrasound is an effective method for monitoring buried lymph node flaps. 3D reconstruction makes it easier to visualize the flap anatomy and detect pathology if it is present. Moreover, the learning curve for the technique is short. Our setup is user-friendly even in the inexperienced hands of asurgical resident, and images can be reevaluated at any time if necessary. The use of 3D reconstruction removes the complications associated with observer-dependent monitoring of VLNT.

Does Fitzpatrick Score Predict Flap Loss? Microsurgical Breast Reconstruction Outcomes of Varying Skin Color.

This is a retrospective study conducted on patients who underwent any type of autologous flap breast reconstruction performed by the two senior authors at an academic center between January 2010 and December 2021. The sole primary outcome variable was flap loss. Patient skin tone was assessed using the Fitzpatrick scale on clinical photographs of patients. A total of 1115 pateints underwent autologous flap breast reconstruction, of which only 56 met both exclusion and inclusion criteria with 58 individual breasts being included in the final study population. The most common race of subjects was White (n = 33; 56.9%) while the most common Fitzpatrick score skin tone was type II (n = 22; 37.9%). The Cochran-Armitage test of trend showed a statistically significant linear trend, P = 0.006, with darker Fitzpatrick score skin tones associated with a higher proportion of flap loss in patients who had vascular compromise. A logistic regression showed that none of the predictor variables were significant. Patients with darker Fitzpatrick skin tones were associated with flap loss after vascular compromise. To prevent flap loss in patients who have darker Fitzpatrick score skin tones, more aggressive flap monitoring should be taken into consideration in the immediate postoperative setting.

Monitor selection according to the defect location in the medial femoral condyle flap,

BackgroundMedial femoral condyle(MFC) flap is frequently used in hand reconstruction, but like other buried flaps, MFC is not easy to monitor and follow.In this study, we present our adipofascial and periosteal tissue technical modifications and results for MFC free flap monitoring and compare different monitoring methods. MethodsTwenty one patients with wrist bone or metacarpal defect reconstructed with MFC flap were included in the study. Adipofascial tissue in wrist defect and periosteal tissue in metacarpal defect were selected as MFC flap's monitor. Patient characteristics, type of injury, flap size, early or late-period complications, flap elevation time,satisfaction scale, visual analogue scale (VAS) and postoperative X-ray view were noted. ResultsThere were 3 female and 18 male patients in the study. The mean age of the patients was 50.8 (38–68). The elevation times of flaps with adipofascial and periosteal monitors were 48 and 53.3 min, respectively. The satisfaction scale averages for the adipofascial and periosteal monitor groups were 3.5 and 3.54, respectively. The VAS scores of the adipofascial and periosteal monitor groups were 2.9 and 3.9, respectively. The flap sizes with periosteal and adipofascial monitors were 10.48 cm3 and 1.36 cm3, respectively. There was no statistically significant difference between flap elevation, VAS, and satisfaction scale (>0.05). There was a statistically significant difference in flap sizes. (<0.05) ConclusionMFC free flap is frequently used in wrist and metacarpal reconstruction. Monitor selection according to the defect area positively affects the prognosis of the flap in the postoperative period.

Application of a strip design to monitor the viability of buried radial forearm free flap in East Asians: A case series study

ObjectivesThe objectives of this study were to evaluate the reliability of a strip design as a monitoring flap in buried flap and to investigate whether strip design of radial forearm free flap (RFFF) could affect donor site morbidity in East Asian. MethodsPatients with externalized flap in buried RFFF were consecutively included in this study. For cases with mucosal defect repair, a skin strip with a 1.5 cm width was proximally positioned to the primary flap along with the pedicle. Compared to a mucosal defect, a skin strip was distally positioned overlying the pedicle (near the wrist) when the flap was used for reinforcing the facial contour, reconstructing sacrificed facial nerve, or reanimating facial expression. The externalized flap formation was performed after completion of anastomoses of vessels. Monitoring results of flap failure using an externalized monitoring flap and additional morbidity of donor site were evaluated. ResultsNine patients were included in this study. Although there were two cases of pharyngeal fistula due to mucosal necrosis of resection margin, transferred RFFF was viable in all cases. The externalized flap provided reliable monitoring for the buried RFFF without a case of necrosis even in two cases with a partial detachment of septocutaneous branches between the radial artery and the designed skin strip. There was no false - positive case. Therefore, the sensitivity and positive predictive value of the externalized monitoring flap were 100%. All defects of radial forearm caused by skin strip harvest were also primarily closed without an additional skin graft. ConclusionA strip design for externalized monitoring flap in RFFF can facilitate an easier creation of externalized monitoring flap in cases with buried RFFF without additional morbidity at the donor site compared to a conventional techniques.

Chimerization of Monitor Flap in a Vascularized Ulnar Nerve Flap Is an Efficient Way for Vascularity Monitoring and the Reinnervation Checkup after Its Transplantation

Background Free vascularized ulnar nerve flaps (VUNF) are effective method for long nerve defects reconstruction. However, the monitorization of its microvascular circulation and the nerve regrowth can be challenging since it is usually designed as a buried flap. We designed a skin paddle based on a septocutaneous perforator from the ulnar artery that can be dissected and raised in conjunction with the vascularized ulnar nerve flap, which aims to improve postoperative monitorization to optimizing the clinical results.Methods We retrospectively reviewed 10 cases with long nerve defects who underwent reconstruction using VUNF between June 2018 and June 2019, including eight acute brachial plexus injuries, 1 multiple nerve injury due to a rolling machine accident, and 1 sequalae of nerve injury after arm replantation. All the demographic data, surgical details, outcomes, and perioperative complications were recorded.Results We evaluated 10 male patients, with a mean age of 34 ± 16 years. Cases included 5 antegrade, 4 retrograde, and 1 U-shaped VUNF. All chimeric skin paddles survived, and all of the underlying nerves presented with adequate circulation and functional improvement. There were no intraoperative or microvascular complications. One skin paddle had a transitory postoperative circulation compromise due to external compression (bandage) which resolved spontaneously after pressure release.Conclusion VUNF chimerization of a septocutaneous perforator skin flap is a relatively easy and efficient method for postoperative monitorization of the nerve's microvascular circulation as well as beneficial for postoperative Tinel's sign checkup to confirm the success of the nerve coaptation. The outcome is potentially improved.

507 Quantifying the Limitations of Clinical and Technology-Based Flap Monitoring Strategies Using A Systematic Recurrent Themes Analysis

Abstract Aim Multiple techniques exist to monitor free flap viability postoperatively, varying with practical and personal preference, yet the limitations of each technique remain unquantified. This systematic review aims to identify the most commonly reported limitations of these techniques in clinical practice. Method A systematic review was conducted according to PRISMA guidelines using MEDLINE, EMBASE and Web of Science with search criteria for postoperative free flap monitoring techniques. Search results were independently screened using defined criteria by two authors and a senior clinician. Limitations of the techniques found in the discussion section of eligible papers were recorded and categorised using recurrent theme analysis. Results A total of 4826 records were identified. 4643 articles met the eligibility criteria and were subsequently reviewed, with 195 papers included in the final analysis. The most frequently reported limitations of clinical monitoring were interpretation requiring expertise (25% of related papers), unsuitability for buried flaps (21%), and lack of quantitative/objective values (19%). For non-invasive technologies: lack of quantitative/objective values (21%), cost (16%) and interpretation requiring expertise (13%). For invasive technologies: application requiring expertise (25%), equipment design and malfunction (13%) and cost (13%). Conclusions This is the first systematic review to quantify the limitations of different flap monitoring techniques as reported in the literature. The limitations identified better inform clinicians to decide the best single or combined monitoring approach for their practice and aid development in new flap monitoring technologies.

Prospective Trial of Near-Infrared Spectroscopy for Continuous Noninvasive Monitoring of Free Fibular Flaps.

Some free flaps develop postoperative vessel thrombosis, which influences the flap survival rate. Early discovery and identification of vascular crisis are critical to the success rate of flap salvage. The primary aims of this study were to determine the features of postoperative blood supply changes in fibular flaps with normal and abnormal blood flow, using near-infrared spectroscopy (NIRS), to monitor oxygenation and blood flow, and to characterize the probable risk factors for vascular crisis. Sixty-three consecutive patients undergoing reconstruction of unilateral mandibular defects with free fibular flaps at the Peking University School of Stomatology were included. Patients were divided into 2 groups, A (n = 38) and B (n = 25); fibular flaps in group A underwent continuous NIRS monitoring from immediately postoperatively until 7 days postoperatively (approximately 150 hours), whereas fibular flaps and opposite mandibles in group B underwent intermittent monitoring: once every 4 hours during the first 24 hours postoperatively and once every 12 hours from 24 to 168 hours postoperatively. Six fibular flaps developed vascular thromboses: 4 were venous thromboses and 2 were arterial thromboses; 5 were rescued after exploration. Of 6 regional oxygen saturation (rSO2) values in the continuous monitoring group, 4 showed no significant differences at any time point compared with the intermittent monitoring group (P > 0.05). The rSO2 of the fibular flap was significantly different from that in the opposite mandible in the first 36 hours postoperatively (P < 0.05). This difference decreased over time. During the initial period of venous thrombosis, rSO2, deoxyhemoglobin, and oxygenated hemoglobin all rose slightly, then showed simultaneous rapid reduction. However, the magnitude of reduction was smaller for deoxyhemoglobin than for oxygenated hemoglobin. Near-infrared spectroscopy can be used for noninvasive and reliable assessment of oxygenation and blood flow in free flaps through continuous, real-time monitoring. It is also portable, inexpensive, and simple to operate. In addition, the detection depth of NIRS is up to 2.0 cm, so it can be used to monitor buried flaps with depths <2.0 cm.

Quantifying the Limitations of Clinical and Technology-based Flap Monitoring Strategies using a Systematic Thematic Analysis.

Background:Multiple techniques exist to monitor free flap viability postoperatively, varying with practical and personal preference, yet the limitations of each technique remain unquantified. This systematic review aims to identify the most commonly reported limitations of these techniques in clinical practice.Methods:A systematic review was conducted according to PRISMA guidelines using MEDLINE, EMBASE, and Web of Science with search criteria for postoperative free flap monitoring techniques. Search results were independently screened using defined criteria by two authors and a senior clinician. Limitations of the techniques found in the discussion section of eligible articles were recorded and categorized using thematic analysis.Results:A total of 4699 records were identified. In total, 2210 articles met the eligibility criteria and were subsequently reviewed, with 195 papers included in the final analysis. The most frequently reported limitations of clinical monitoring were interpretation requiring expertise (25% of related papers), unsuitability for buried flaps (21%), and lack of quantitative/objective values (19%). For noninvasive technologies, the limitations were lack of quantitative/objective values (21%), cost (16%), and interpretation requiring expertise (13%). For invasive technologies, the limitations were application requiring expertise (25%), equipment design and malfunction (13%), and cost (13%).Conclusions:This is the first systematic review to quantify the limitations of different flap monitoring techniques, as reported in the literature. This information may enhance the choice in monitoring strategy for a reconstructive service, and inform the development and refinement of new flap monitoring technologies.

The use of sentinel skin islands for monitoring buried and semi-buried micro-vascular flaps. Part II: Clinical application.

Despite the high success rate of micro-vascular flaps, anastomosis compromise occurs in 5-10% and that can lead to flap failure. Reliable monitoring of the flap is therefore of similar importance to that of the precise surgical procedure itself. Multiple methods have been reported for monitoring of the flap vitality, the first one being direct visual monitoring. In buried flaps direct visualisation is not feasible or is unreliable. In these cases we can extend the buried flap to expose a segment of it to act as a monitoring sentinel. For the purpose of this review we used our clinical experience as a starting point, and for the extended information and expertise we conducted a search of the PubMed database. Over 40 monitoring techniques have been reported to-date. Direct visual monitoring is still generally used method with a reliability of up to 100% and an overall success rate of up to 99%. Direct visualisation remains as the simplest, cheapest and yet a very reliable method of flap monitoring. In this review we provide a description of various possible techniques for externalising part of a buried flap, define the tissues that can be used for this purpose and we summarise the procedures that should be followed to achieve the best reliability and validity of monitoring the skin island.

Chromophore reconstruction at depth in bilayered media: a method for quantification.

We report a method for deriving the absolute value of absorption coefficients at depth in bilayered media. The method was simplified from that of time-resolved diffuse optical tomography (TR-DOT) into one dimension to validate and set up the main parameters with the help of simulations, and to test it in an easy preclinical model. The method was applied to buried flaps as used in reconstructive surgery, and absolute chromophore concentrations in the flap and in the upper (skin and fat) layer were derived. The encouraging results obtained lay a foundation for developing more complex multidimensional models.

Patchwork Flap for Immediate Nipple-Areolar Complex Reconstruction

Loss of nipple projection is commonly encountered during nipple-areolar reconstruction. The patchwork flap was developed to overcome this problem. The thickness of the buried dermofat flap can be modified to the desired nipple projection. Areolar is reconstructed with multiple skin flap islands, which negates the need for skin grafting. The dimensions of the skin islands can be modified to the desired areolar size.

Noninvasive Monitoring of Deep Tissue Oxygenation in Buried Flaps by Time-Resolved Near-Infrared Spectroscopy in Pigs.

Flap monitoring in reconstructive surgery is particularly important because flap failure is a dramatic event for the patient and for the medical team. Noninvasive deep tissue oxygenation monitoring is a challenge. The aim of this experimental study was to assess the performance of time-resolved near-infrared spectroscopy compared with continuous-wave near-infrared spectroscopy and with invasive oxygen partial pressure measurement in pigs. Thirty fasciocutaneous flaps based on the superficial epigastric inferior pedicle were harvested and buried under the transcutaneous dorsal muscle (approximately 1 cm thick). An optical probe was placed on the skin above each buried flap. For each pig, two buried flaps were performed, one submitted to arterial occlusion and one to venous occlusion. Oxyhemoglobin and deoxyhemoglobin concentrations were observed for over 40 minutes before clamping, almost 20 minutes during clamping and during a period of release of approximately 20 minutes. Variations in time-resolved near-infrared spectroscopy were compared to the oxygen partial pressure and continuous-wave near-infrared spectroscopy variations. All vascular events were detected by the time-resolved near-infrared spectroscopy. During arterial clamping, oxyhemoglobin decreased rapidly, whereas deoxyhemoglobin increased moderately. The divergence of oxyhemoglobin and deoxyhemoglobin curves indicated arterial occlusion. During venous clamping, deoxyhemoglobin increased, whereas oxyhemoglobin increased briefly then remained stable or decreased moderately. The initial increases in the oxyhemoglobin and deoxyhemoglobin curves indicated venous occlusion. Oxygen partial pressure failed to detect vascular events in three cases. Continuous-wave near-infrared spectroscopy could not clearly identify vascular occlusions. Thus, the authors demonstrated the relevance of time-resolved near-infrared spectroscopy to buried flap monitoring. Time-resolved near-infrared spectroscopy could differentiate between arterial occlusion and venous occlusion.

Externally Monitored Versus Conventional Buried Flaps in Laryngopharyngeal Reconstruction.

ObjectivesTo compare the surgical outcomes of externally monitored and conventional buried flaps with the goal of determining the usefulness of external monitoring of buried flaps.MethodsIn this case-control study with propensity score matching, 30 patients were evenly divided into externally monitored buried flap and conventional buried flap groups. The total operative time for free flap reconstruction, the flap survival rate, the length of hospital stay, the initial time of a reliable visual assessment, complications, the final diet achieved, and the duration until diet initiation were compared between the groups.ResultsThe mean operative time for reconstruction was 115 minutes (interquartile range, 85–150 minutes) and 142 minutes (interquartile range, 95–180 minutes) in the externally monitored and conventional groups, respectively (P= 0.245). The median length of hospital stay was 24 days (interquartile range, 18–30 days) and 27 days (interquartile range, 20–41 days) in the externally monitored and conventional groups, respectively (P=0.298). The median duration until diet initiation was 15 days (interquartile range, 15–21 days) and 18 days (interquartile range, 15–34 days) in the externally monitored and conventional groups, respectively (P=0.466). The final diet, initial time of a reliable visual assessment, and complications were comparable between the groups, but the external skin paddle provided an excellent visual assessment immediately postoperatively in all cases.Conclusion The outcomes were comparable between the groups, indicating that externalization of the cutaneous component of a buried flap may be a straightforward and useful technique for monitoring a buried anterolateral thigh free flap in laryngopharyngeal reconstructions. The salvage and false-positive rates of compromised flaps should be compared in large subject groups in future studies to prove that the use of an external skin paddle improves flap monitoring.