The modified 5-item frailty index is a predictor of perioperative risk in head and neck microvascular reconstruction: An analysis of 3795 cases.

BACKGROUND: The modified frailty index 5 (mFI-5)-a scale based on the five variables diabetes, hypertension, chronic obstructive pulmonary disease, congestive heart failure, and functional dependency-has been shown to be a valid predictor of surgical outcomes. In this study we sought to evaluate the ability of the mFI-5 to predict the postoperative outcomes of head and neck microvascular reconstruction. METHODS: Review of the 2015-2019 American College of Surgeons, National Surgical Quality Improvement Program (ACS NSQIP) database identified 5323 cases of microvascular reconstruction, of which 3795 were head and neck cases that provided parameters necessary to calculate the mFI-5. The groups were compared in terms of demographics and comorbidities. Post-operative outcomes assessed included mortality, average operative time and length of hospital stay, surgical and medical complications, and non-home discharge. RESULTS: Increases in the mFI were associated with longer hospitalization periods (10.5 ± 7.5 days in mFI 0 vs 14.9 ± 15.4 in mFI ≥ 3; p < 0.0001) higher rates of mortality (1% in mFI 0 vs 3.1% in mFI ≥ 3; p = 0.02), reoperation (15.4% in mFI 0 vs 17.2% in mFI ≥ 3; p = 0.002) and unplanned readmission (7.6% in mFI 0 vs 18.8% in mFI ≥ 3; p = 0.001). Rates of any complications (p < 0.0001), as well as surgical (p < 0.002) and medical (p < 0.0001) complications specifically were higher with greater mFI scores. Higher mFI scores also predicted decreased home discharge (p < 0.0001). Differences remained significant on multivariate analysis and subgroup analysis by age. CONCLUSION: The mFI-5 is a significant predictor of risk in microvascular head and neck reconstruction. Subgroup analysis by age highlights that the tool can help identify younger patients who are frail and hence at risk. Through appropriate pre-operative identification of frail patients surgeons can prospectively modify their operative and discharge planning as well as post-operative support.

Remote monitoring of head and neck free flaps using near infrared spectroscopic tissue oximetry.

PURPOSE: Near infrared spectroscopy (NIRS) measures tissue oximetry and perfusion of free tissue transfer with the advantage of remote wireless monitoring for free tissue transfer. It has been widely used in breast and extremity reconstruction but has had limited adoption in the head and neck. MATERIALS AND METHODS: A retrospective review of head and neck microvascular reconstruction by three different surgical services over 15 months at one tertiary care hospital was performed. Demographics, flap type, monitoring technique, complications, and flap outcomes were recorded. Monitoring techniques were (1) implantable/handheld Doppler or (2) NIRS. Flap monitoring outcomes were evaluated using multivariate analysis. RESULTS: 119 flaps were performed by four surgeons with a success rate of 92% (109/119). Flaps were monitored with Doppler (40%) or NIRS (60%). There was no difference in flap success based on monitoring technique. An ROC analysis identified that the optimal cutoff in immediate StO2 for classifying flap success at discharge was 68%. CONCLUSIONS: NIRS was successfully implemented in a high-volume head and neck reconstructive practice. NIRS remote monitoring allowed for flap surveillance without requiring in-hospital presence and was able to identify both arterial and venous compromise.

A segmentation-independent volume rendering visualisation method might reduce redundant explorations and post-surgical complications of microvascular decompression.

OBJECTIVES: This study aimed to investigate the feasibility of segmentation-independent volume rendering (SI-VR) in visualising the root entry zone (REZ), and to explore the influence on the management of vascular compression syndromes (VCSs). METHODS: Two hundred and twenty patients with VCSs were recruited in this prospective study from July 2015 to May 2019. SI-VR was reconstructed based on inverted 3D fast spin echo T2WI. They were assigned to the experimental group and control group randomly. Patients in the experimental group would accept extra evaluation based on SI-VR before microvascular decompression. Image quality and diagnostic accuracy between SI-VR and 3D fast spin echo T2WI in the experimental group were compared by Mann-Whitney U test and chi-square test, separately. Interobserver agreement was performed with intraclass correlation coefficient. Postsurgical outcomes and complications between two groups were compared by chi-square test. RESULTS: SI-VR had a better interobserver agreement (0.82 vs 0.68) and diagnostic accuracy (95.5% vs 83.6%, p = 0.004) than that of 3D fast spin echo T2WI. Especially, significantly improved diagnostic accuracy was reached in detecting the multi-vascular branches compression (100% vs 15.4%, p < 0.001). There were fewer complications (7.1% vs 26.8%, p = 0.004) and less operation time (20.7 min vs 14.5 min, p = 0.007) but no significant difference of pain relief (p = 0.19) in the experimental group than in the control group. CONCLUSIONS: The SI-VR method is feasible for the precise demonstration of the anatomy structure along the REZ, with high reliability and reproducibility. Unbiased pre-surgical visualisation could reduce redundant explorations and post-surgical complications in patients who undergo microvascular decompression. KEY POINTS: • Visualisation of the root entry zone by the segmentation-independent volume rendering is in accordance with the landscape by the neuro-endoscopy. • Segmentation-independent volume rendering has an advantage over 3D fast spin echo T2WI in the visualisation of multi-vascular branches compression. • Presurgical 3D visualisation of the neurovascular compression at the root entry zone leads to less postsurgical complications from the decrease of redundant exploration.

Low molecular weight heparin for prevention of microvascular occlusion in digital replantation.

BACKGROUND: The success of digital replantation is highly dependent on the patency of the repaired vessels after microvascular anastomosis. Antithrombotic agents are frequently used for preventing vascular occlusion. Low molecular weight heparin (LMWH) has been reported to be as effective as unfractionated heparin (UFH) in peripheral vascular surgery, but with fewer adverse effects. Its benefit in microvascular surgery such as digital replantation is unclear. This is an update of the review first published in 2013. OBJECTIVES: To assess if treatment with subcutaneous LMWH improves the salvage rate of the digits in patients with digital replantation after traumatic amputation. SEARCH METHODS: The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, AMED and CINAHL databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers, to 17 March 2020. The authors searched PubMed, China National Knowledge Infrastructure (CNKI) and Chinese Electronic Periodical Services (CEPS) on 17 March 2020 and sought additional trials from reference lists of relevant publications. SELECTION CRITERIA: We included randomised or quasi-randomised controlled trials comparing treatment with LMWH versus any other treatment in participants who received digital replantation following traumatic digital amputation. DATA COLLECTION AND ANALYSIS: Two review authors (PL, CC) independently extracted data and assessed the risk of bias of the included trials using Cochrane's 'Risk of bias' tool. Disagreements were resolved by discussion. We assessed the certainty of evidence using the GRADE approach. MAIN RESULTS: We included two new randomised trials in this update, bringing the total number of included trials to four. They included a total of 258 participants, with at least 273 digits, from hospitals in China. Three studies compared LMWH versus UFH, and one compared LMWH versus no LMWH. The mean age of participants ranged from 24.5 to 37.6 years. In the studies reporting the sex of participants, there were a total of 145 men and 59 women. The certainty of the evidence was downgraded to low or very low because all studies were at high risk of performance or reporting bias (or both) and there was imprecision in the results due to the small numbers of participants. The three studies comparing LMWH versus UFH reported the success rate of replantation using different units of analysis (participant or digit), so we were unable to combine data from all three studies (one study reported results for both participants and digits). No evidence of a benefit in success of replantation was seen in the LMWH group when compared with UFH, regardless of whether the outcomes were reported by number of participants (risk ratio (RR) 0.98, 95% confidence interval (CI) 0.87 to 1.10; 130 participants, 2 studies; very low-certainty evidence); or by number of digits (RR 0.97, 95% CI 0.90 to 1.04; 200 digits, 2 studies; low-certainty evidence). No studies reported the incidence of compromised microcirculation requiring surgical or non-surgical therapy, or any systemic/other causes of microvascular insufficiency. There was no evidence of a clear difference between the LMWH and UFH groups in occurrence of arterial occlusion (RR 1.08, 95% CI 0.16 to 7.10; 54 participants, 1 study; very low-certainty evidence) or venous occlusion (RR 0.81, 95% CI 0.20 to 3.27; 54 participants, 1 study; very low-certainty evidence). Two studies reported adverse effects. The LMWH and UFH groups showed no evidence of a difference in wound bleeding (RR 0.53, 95% CI 0.23 to 1.23; 130 participants, 2 studies; low-certainty evidence), haematuria (RR 0.43, 95% CI 0.09 to 2.11; 130 participants, 2 studies; very low-certainty evidence), ecchymoses (RR 0.82, 95% CI 0.21 to 3.19; 130 participants, 2 studies; very low-certainty evidence), epistaxis (RR 0.27, 95% CI 0.03 to 2.32; 130 participants, 2 studies; very low-certainty evidence), gingival bleeding (RR 0.18, 95% CI 0.02 to 1.43; 130 participants, 2 studies; very low-certainty evidence), and faecal occult blood (RR 0.27, 95% CI 0.03 to 2.31; 130 participants, 2 studies; very low-certainty evidence). We could not pool data on coagulation abnormalities as varying definitions and tests were used in the three studies. One study compared LMWH versus no LMWH. The success rate of replantation, when analysed by digits, was reported as 91.2% success in the LMWH group and 82.1% in the control group (RR 1.11, 95% CI 0.93 to 1.33; 73 digits, 1 study; very low-certainty evidence). Compromised microcirculation requiring surgical re-exploration, analysed by digits, was 11.8% in the LMWH group and 17.9% in the control group (RR 0.86, 95% CI 0.21 to 3.58; 73 digits, 1 study; very low-certainty evidence). Compromised microcirculation requiring incision occurred in five out of 34 digits (14.7%) in the LMWH group and eight out of 39 digits (20.5%) in the control group (RR 0.72, 95% CI 0.26 to 1.98; 73 digits; very low-certainty evidence). Microvascular insufficiency due to arterial occlusion, analysed by digits, was 11.8% in the LMWH group and 17.9% in the control group (RR 0.66, 95% CI 0.21 to 2.05; 73 digits, 1 study; very low-certainty evidence), and venous occlusion was 14.7% in the LMWH group and 20.5% in the control (RR 0.72, 95% CI 0.26 to 1.98; 73 digits, 1 study; very low-certainty evidence). The study did not report complications or adverse effects. AUTHORS' CONCLUSIONS: There is currently low to very low-certainty evidence, based on four RCTs, suggesting no evidence of a benefit from LMWH when compared to UFH on the success rates of replantation or affect microvascular insufficiency due to vessel occlusion (analysed by digit or participant). LMWH had similar success rates of replantation; and the incidence rate of venous and arterial microvascular insufficiency showed no evidence of a difference between groups when LMWH was compared to no LMWH (analysed by digit). Similar rates of complications and adverse effects were seen between UFH and LMWH. There was insufficient evidence to draw conclusions on any effect on coagulation when comparing LMWH to UFH or no LMWH. The certainty of the evidence was downgraded due to performance and reporting bias, as well as imprecision in the results. Further adequately powered studies are warranted to provide high-certainty evidence.

Value of T1 mapping on gadoxetic acid-enhanced MRI for microvascular invasion of hepatocellular carcinoma: a retrospective study.

BACKGROUND: To evaluate the utility of non-invasive parameters derived from T1 mapping and diffusion-weighted imaging (DWI) on gadoxetic acid-enhanced MRI for predicting microvascular invasion (MVI) of hepatocellular carcinoma (HCC). METHODS: A total of 94 patients with single HCC undergoing partial hepatectomy was analyzed in this retrospective study. Preoperative T1 mapping and DWI on gadoxetic acid-enhanced MRI was performed. The parameters including precontrast, postcontrast and reduction rate of T1 relaxation time and apparent diffusion coefficient (ADC) values were measured for differentiating MVI-positive HCCs (n = 38) from MVI-negative HCCs (n = 56). The receiver operating characteristic curve (ROC) was analyzed to compare the diagnostic performance of the calculated parameters. RESULTS: MVI-positive HCCs demonstrated a significantly lower reduction rate of T1 relaxation time than that of MVI-negative HCCs (39.4% vs 49.9, P < 0.001). The areas under receiver operating characteristic curve (AUC) were 0.587, 0.728, 0.824, 0,690 and 0.862 for the precontrast, postcontrast, reduction rate of T1 relaxation time, ADC and the combination of reduction rate and ADC, respectively. The cut-off value of the reduction rate and ADC calculated through maximal Youden index in ROC analyses was 44.9% and 1553.5 s/mm2. To achieve a better diagnostic performance, the criteria of combining the reduction rate lower than 44.9% and the ADC value lower than 1553.5 s/mm2 was proposed with a high specificity of 91.8% and accuracy of 80.9%. CONCLUSIONS: The proposed criteria of combining the reduction rate of T1 relaxation time lower than 44.9% and the ADC value lower than 1553.5 s/mm2 on gadoxetic acid-enhanced MRI holds promise for evaluating MVI status of HCC.

Microvascular Replantation of Totally Avulsed Scalps: Failures and Successes.

Total scalp avulsion is a rare but devastating injury currently without proven reconstructive techniques. While microsurgical anastomosis procedures have advanced and allowed for the replantation of digits and limbs, special anatomical considerations and risk of fatal blood loss add to the difficulty of replanting totally avulsed scalps. The authors present their replantation experience of 4 totally avulsed scalps between 2008 and 2017. Despite meticulous reconstructive techniques with proven success in limb and digit replantation, the first 3 cases failed due to various factors (i.e., thrombosis, venous congestion, reavulsion), and with experience, the fourth case was successful. Since total scalp avulsions are rare injuries, case reports are scarce, with only few publications commenting on failures which hold crucial information for surgeons to avoid pitfalls and optimize techniques. In this article, we highlight our experience with both successful and failed replantation of totally avulsed scalps, and offer recommendations and insight for optimization of this rare procedure.

Prognostic Value and Prediction of Extratumoral Microvascular Invasion for Hepatocellular Carcinoma.

BACKGROUND: There are few reports on microvascular invasion (MVI) located intra- or extratumorally and prognosis of hepatocellular carcinoma (HCC). OBJECTIVE: The aim of this study was to evaluate patient outcome according to the location of MVI, and to build a nomogram predicting extratumoral MVI. METHODS: We included 681 consecutive patients who underwent hepatic resection (HR) or liver transplantation (LT) for HCC from January 1994 to June 2012, and evaluated patient outcome according to the degree of vascular invasion (VI). A nomogram for predicting extratumoral MVI was created using 637 patients, excluding 44 patients with macrovascular invasion, and was validated using an internal (n = 273) and external patient cohort (n = 256). RESULTS: The 681 patients were classified into four groups based on pathological examination (148 no VI, 33 intratumoral MVI, 84 extratumoral MVI, and 29 macrovascular invasion in patients who underwent HR; 238 no VI, 50 intratumoral MVI, 84 extratumoral MVI, and 15 macrovascular invasion in patients who underwent LT). Multivariate analysis revealed that extratumoral MVI was an independent risk factor for overall survival in patients who underwent HR (hazard ratio 2.62, p < 0.0001) or LT (hazard ratio 1.99, p = 0.0005). Multivariate logistic regression analysis identified six independent risk factors for extratumoral MVI: α-fetoprotein, tumor size, non-boundary type, alkaline phosphatase, neutrophil-to-lymphocyte ratio, and aspartate aminotransferase. The nomogram for predicting extratumoral MVI using these factors showed good concordance indices of 0.774 and 0.744 in the internal and external validation cohorts, respectively. CONCLUSIONS: The prognostic value of MVI differs according to its invasiveness. The nomogram allows reliable prediction of extratumoral MVI in patients undergoing HR or LT.

Microcirculation in Cardiovascular Diseases.

Microcirculation is a system composed of interconnected microvessels, which is responsible for the distribution of oxygenated blood among and within organs according to regional metabolic demand. Critical medical conditions, e. g., sepsis, and heart failure are known triggers of microcirculatory disturbance, which usually develops early in such clinical pictures and represents an independent risk factor for mortality. Therefore, hemodynamic resuscitation aiming at restoring microcirculatory perfusion is of paramount importance. Until recently, however, resuscitation protocols were based on macrohemodynamic variables, which increases the risk of under or over resuscitation. The introduction of hand-held video-microscopy (HVM) into clinical practice has allowed real-time analysis of microcirculatory variables at the bedside and, hence, favored a more individualized approach. In the cardiac intensive care unit scenario, HVM provides essential information on patients' hemodynamic status, e. g., to classify the type of shock, to adequate the dosage of vasopressors or inotropes according to demand and define safer limits, to guide fluid therapy and red blood cell transfusion, to evaluate response to treatment, among others. Nevertheless, several drawbacks have to be addressed before HVM becomes a standard of care.

Robot-assisted microvascular anastomosis in head and neck free flap reconstruction: Preliminary experiences and results.

BACKGROUND: The da Vinci Surgical System has facilitated considerable advancements in surgery. The process and results of robot-assisted microvascular anastomosis in real clinical situations have rarely been reported. This study presents our experience of performing robot-assisted microvascular anastomosis in free flap reconstruction in patients with oropharyngeal cancer. PATIENTS AND METHODS: This was a retrospective study of reconstructive operations using a free radial forearm flap for oropharyngeal defects after tumor extirpation in 15 consecutive adult patients (12 men and 3 women). In total, 17 robot-assisted microvascular vessel anastomoses (2 arteries and 15 veins) were performed; moreover, 13 arteries and 13 veins were anastomosed using the standard operating microscope and hand-sewing technique. RESULTS: The recipient and donor vessel diameters were 2.5 ± 0.7 and 2.1 ± 0.8 mm, respectively. The donor blood vessel diameter selected for anastomosis using da Vinci Surgical System was significantly smaller (2.1 ± 0.8 vs. 2.5 ± 0.6 mm) than that for a standard operating microscope and hand-sewing technique (p = .021), the operating time spent (38.4 ± 10.4 vs. 28.0 ± 7.7 min) was significantly longer (p < .001). The vascular patency rate was 100%, and all flaps survived without requiring additional operation for revision. CONCLUSION: Robotic surgical systems can facilitate vascular microanastomosis and provide a blood vessel patency rate comparable to that of a standard operating microscope and hand-sewing technique.

Impact of advanced age on microvascular reconstruction of the lower facial third: An American College of Surgeons NSQIP study.

BACKGROUND: Microvascular reconstruction is the standard of care in head and neck reconstruction, though its perioperative safety in an older population has been controversial due to safety concerns, warranting further investigation. MATERIALS AND METHODS: An "older" (≥71 years) cohort undergoing reconstruction after mandibulectomy/glossectomy was compared to the remaining population in a National Surgical Quality Improvement Program (2008-2016) analysis. Cases required both a mandibulectomy/glossectomy and microvascular or local flap reconstruction (exclusion criteria: missing ages and simultaneous microvascular and local flap reconstruction). Demographics, comorbidities, and procedure types were analyzed on 985 patients (236 [24.4%] were ≥71). Outcomes were compared by reconstruction type. Regressions were performed calculating the impact of age on length of hospital stay (LOHS) and operative time. RESULTS: Ablative procedures were comparable, but older patients received local flaps at higher rates (22.5% vs. 9.6%; p < .001). The older population had more comorbidities (higher ASA class [p < .001], diabetes [p < .001], and hypertension [p < .001]). After Bonferroni correction, univariate subgroup analyses of soft tissue and bone/composite microvascular flaps revealed similar outcomes (except increased medical complications in the older cohort undergoing a bone free flap [p = .002]). Controlling for a variety of factors, older age resulted in longer LOHS (B: 1.4 days; 95% CI: 0.1-2.8 days; p = .035), but not operative time (B: -21.90 min; 95% CI: -52.76 to 8.96 min; p = .164). CONCLUSION: While increased age (≥70 years) was associated with a longer LOHS, complication rates were comparable. Although limited by the retrospective nature, evidence supports microvascular reconstruction in the elderly population with comparable outcomes.

[Treatment of necrotizing infection in patients with chronic arterial insufficiency of the lower extremities]. / Rezul'taty lecheniia nekrotiziruiushchei infektsii u patsientov s khronicheskoi arterial'noi nedostatochnost'iu nizhnikh konechnostei.

OBJECTIVE: To analyze the effectiveness of complex therapy of necrotizing infection using the original method of stimulation of angiogenesis in patients with chronic arterial insufficiency of the lower extremities. MATERIAL AND METHODS: In 53 patients, operations were performed using the proposed technologies for stimulation of angiogenesis. A control group consisting of 56 patients was formed to compare the results of treatment. They had standard vascular therapy for the correction of ischemia. Morphological studies of the muscles of the lower extremities included assessment of capillary bed density and spatial orientation of the capillaries before and after treatment. Computed angiography of the lower extremities followed by calculation of perfusion index was performed to assess changes in the microvasculature. Clinical evaluation of the results was carried out using R. Rutherford scale. RESULTS: Revascularization resulted significant augmentation of capillary bed density and the number of functioning capillaries in muscular tissue. This was accompanied by increased perfusion index and TcPO2 values. The effect of treatment is observed in 12-14 days after surgery and persists for a long time. The best outcomes are found in patients with ischemia grade IIb-III. Incidence of lower limb amputations was more than 2 times lower in the main group compared with the control group. CONCLUSION: Combined stimulation of angiogenesis including mechanical tunneling of the muscles of the affected limb and administration of platelet rich plasma is effective procedure. This method does not require complex equipment and may be used in the treatment of patients with complications of chronic lower limb ischemia and contraindicated direct arterial reconstruction.

Vascular architecture in free flaps: Analysis of vessel morphology and morphometry in murine free flaps.

The aim of this study was to analyze the development of vascular architecture as well as vascular morphometry and morphology of anastomosed microvascular free flaps. Free pectoral skin flaps were raised in 25 rats and anastomosed to the femoral vessels in the groin region. CD31 immunohistology was performed after 3, 7 and 12 d (each 5 animals each) to analyze microvessel density (MVD), microvessel area (MVA) and microvessel size (MVS). Microvascular corrosion casting was performed after 7 and 12 d (5 animals each) to analyze vessel diameter (VD), intervascular distance (IVD), interbranching distance (IBD), and branching angle (BA). Further on, sprout and pillar density as hallmarks of sprouting and intussusceptive angiogenesis were analyzed. Pectoral skin isles from the contralateral side served as controls. A significantly increased MVD was found after 7 and 12 d (p each <0.001). MVA was significantly increased after 3, 7 and 12 d (p each <0.001) and a significantly increased MVS was analyzed after 3 and 7 d (p each <0.001). VD and IVD were significantly increased after 7 and 12 d (p each <0.001). For IBD, a significantly increase was measured after 7 d (p < 0.001). For IBA, sprout and pillar density, no significant differences were found (p each ≥0.05). Significant changes in the vascular architecture of free flaps after successful microvascular anastomosis were seen. Since there was no evidence for sprout and pillar formation within the free flaps, the increased MVD and flap revascularization might be induced by the receiving site.

Hyperspectral imaging for monitoring of perfusion failure upon microvascular anastomosis in the rat hind limb.

BACKGROUND/PURPOSE: Objective, reliable and easy monitoring of microvascular tissue perfusion is a goal that was achieved for many years with limited success. Therefore, a new non-invasive hyperspectral camera system (TIVITA™) was tested for this purpose in an in vivo animal model. METHODS: Evaluation of tissue oxygenation during ischemia and upon reperfusion was performed in left hind limb in a rat model (n=20). Ischemia was induced by clamping and dissection of the superficial femoral artery. Reperfusion of the limb was achieved by microsurgical anastomosis of the dissected artery. Oxygenation parameters of the hind limb were assessed via TIVITA™ before and immediately after clamping and dissection of the artery, 3 and 30min after reperfusion as well as on postoperative days 1 and 2. Thereby, the non-operated hind limb served as control. As clinical parameters, the refill of the anastomosis as well as the progress of the affected leg were assessed. RESULTS: In 12 from 20 cases, TIVITA™ recorded a sufficient reperfusion with oxygenation parameters comparable to baseline or control condition. However, in 8 from 20 cases oxygenation was found impaired after reperfusion causing a re-assessment of the microvascular anastomosis. Thereby, technical problems like stenosis or local thrombosis were found in all cases and were surgically treated leading to an increased tissue oxygenation. CONCLUSIONS: The TIVITA™ camera system is a valid non-invasive tool to assess tissue perfusion after microvascular anastomosis. As it safely shows problems in oxygenation, it allows the clinician a determined revision of the site in time in order to prevent prolonged ischemia.

One year Rat Study of iBTA-induced "Microbiotube" Microvascular Grafts With an Ultra-Small Diameter of 0.6 mm.

OBJECTIVE: The world's smallest calibre "microbiotube" vascular graft was recently developed, with an inner diameter of 0.6 mm. It was formed using in-body tissue architecture (iBTA) and has a high degree of patency and capacity for regeneration in the acute phase, 1 month after implantation. This consecutive study investigated the compatibility and stability of microbiotubes in the chronic phase of implantation for 12 months for potential application in microsurgery. METHODS: This was an in vivo experimental study. The microbiotubes were prepared by embedding the mould subcutaneously in rats for 2 months. Allogenic microbiotubes (n = 16) were implanted into the bilateral femoral arteries (inner diameter 0.5 mm) of eight Wistar rats in an end to end anastomosis manner for 12 months. Follow up 7-Tesla magnetic resonance angiograms were performed every 3 months. Histological observation was performed 12 months after implantation. RESULTS: All patent grafts (n = 12, patency 75%) one month after implantation maintained their patency up to 12 months without any abnormal morphological changes or calcification. Histological observation at 12 months showed that layered α-smooth muscle actin positive cells with a monolayer luminal covering of endothelial cells had formed from the proximal to the distal anastomoses. A thin elastic fibre layer formed in the luminal area. After implantation, all components of the microbiotube were similar to those of a native artery. CONCLUSIONS: This study suggests that microbiotubes have high compatibility, stability, and durability as replacement grafts over the short to mid-term period.

Assessment of the use of contrast enhanced ultrasound in guiding microdissection testicular sperm extraction in nonobstructive azoospermia.

BACKGROUND: The aim of this study is to assess the value of contrast-enhanced ultrasound (CEUS) as a new non-invasive approach to locate the testicular area in which spermatogenesis is most likely to be found in non-obstructive azoospermic testes and to evaluate the accuracy of CEUS as a predictor of successful sperm retrieval. METHODS: CEUS was performed in 120 nonobstructive azoospermia (NOA) patients. Microdissection testicular sperm extraction (M-TESE) was performed on the best and poorest perfusion areas selected by CEUS and on conventional areas. RESULTS: In the 187 testicles that underwent M-TESE, the sperm retrieval rates (SRRs) in the best perfusion area and poorest perfusion area over the maximal longitudinal section and conventional area were 63.1, 34.7 and 47.1%. According to receiver operating characteristic (ROC) analysis, the arrival times (AT) ≤27 s, time-to-peak intensity (TTP) ≤45 s, and peak intensity (PI) ≥11 dB were the best predictors of positive sperm retrieval. The location of the best perfusion area was able to guide M-TESE to improve the success rates. CONCLUSIONS: Testicle CEUS is suggested to be performed in all patients with NOA. If AT≤27 s, TTP ≤ 45 s or PI≥11 dB are found in the best perfusion area, M-TESE is strongly recommended.

Need for normalization: the non-standard reference standard for microvascular invasion diagnosis in hepatocellular carcinoma.

BACKGROUND: Preoperative microvascular invasion (MVI) assessment in hepatocellular carcinoma (HCC) is one of the current research focuses, with studies reporting controversial results regarding MVI-associated risk factors. As a possible source of bias, reported MVI rate (percentage of MVI-positive patients) varies a lot among studies. Pathological examination should have been the golden criteria of MVI diagnosis, but no standard and generally adopted pathological examination protocol exists. METHODS AND RESULTS: It is highly possible that underestimated pathological diagnosis of MVI exists. We present two likely examples to stress the problem and indicate the root of the problem partially being an unreliable pathological examination. Results of studies basing on unreliable reference standard can be less convincing and even misleading, which is the most basic and fundamental problem in this research field. CONCLUSION: There is an urgent need to settle the disputes regarding pathological sampling, microscopy, and reporting, in order to promote future academic exchange and consensus development on MVI assessment. Several concerns about pathological MVI assessment should be focused on in the future research as we put up in the review.

Bridging veins and veins of the brainstem in microvascular decompression surgery for trigeminal neuralgia and hemifacial spasm.

OBJECTIVE In microvascular decompression surgery for trigeminal neuralgia and hemifacial spasm, the bridging veins are dissected to provide the surgical corridors, and the veins of the brainstem may be mobilized in cases of venous compression. Strategy and technique in dissecting these veins may affect the surgical outcome. The authors investigated solutions for minimizing venous complications and reviewed the outcome for venous decompression. METHODS The authors retrospectively reviewed their surgical series of microvascular decompression for trigeminal neuralgia and hemifacial spasm in patients treated between 2005 and 2017. Surgical strategies included preservation of the superior petrosal vein and its tributaries, thorough dissection of the arachnoid sleeve that enveloped these veins, cutting of the inferior petrosal vein over the lower cranial nerves, and mobilization or cutting of the veins of the brainstem that compressed the nerve roots. The authors summarized the patient characteristics, operative findings, and postoperative outcomes according to the vascular compression types as follows: artery alone, artery and vein, and vein alone. They analyzed the data using chi-square and 1-way ANOVA tests. RESULTS The cohort was composed of 121 patients with trigeminal neuralgia and 205 patients with hemifacial spasm. The superior petrosal vein and its tributaries were preserved with no serious complications in all patients with trigeminal neuralgia. Venous compression alone and arterial and venous compressions were observed in 4% and 22%, respectively, of the patients with trigeminal neuralgia, and in 1% and 2%, respectively, of those with hemifacial spasm (p < 0.0001). In patients with trigeminal neuralgia, 35% of those with artery and venous compressions and 80% of those with venous compression alone had atypical neuralgia (p = 0.015). The surgical cure and recurrence rates of trigeminal neuralgias with venous compression were 60% and 20%, respectively, and with arterial and venous compressions the rates were 92% and 12%, respectively (p < 0.0001, p = 0.04). In patients with hemifacial spasm who had arterial and venous compressions, their recurrence rate was 60%, and that was significantly higher compared to other compression types (p = 0.0008). CONCLUSIONS Dissection of the arachnoid sleeve that envelops the superior petrosal vein may help to reduce venous complications in surgery for trigeminal neuralgia. Venous compression may correlate with worse prognosis even with thorough decompression, in both trigeminal neuralgia and hemifacial spasm.

"Internet of Things" Real-Time Free Flap Monitoring.

BACKGROUND: Free flaps are a common treatment option for head and neck reconstruction in plastic reconstructive surgery, and monitoring of the free flap is the most important factor for flap survival. In this study, the authors performed real-time free flap monitoring based on an implanted Doppler system and "internet of things" (IoT)/wireless Wi-Fi, which is a convenient, accurate, and efficient approach for surgeons to monitor a free flap. METHODS: Implanted Doppler signals were checked continuously until the patient was discharged by the surgeon and residents using their own cellular phone or personal computer. If the surgeon decided that a revision procedure or exploration was required, the authors checked the consumed time (positive signal-to-operating room time) from the first notification when the flap's status was questioned to the determination for revision surgery according to a chart review. To compare the efficacy of real-time monitoring, the authors paired the same number of free flaps performed by the same surgeon and monitored the flaps using conventional methods such as a physical examination. RESULTS: The total survival rate was greater in the real-time monitoring group (94.7% versus 89.5%). The average time for the real-time monitoring group was shorter than that for the conventional group (65 minutes versus 86 minutes). CONCLUSIONS: Based on this study, real-time free flap monitoring using IoT technology is a method that surgeon and reconstruction team can monitor simultaneously at any time in any situation.

[Microvascular reconstruction of the larynx following total laryngectomy]. / Mikrovaskuläre Kehlkopfrekonstruktion nach totaler Laryngektomie.

Total laryngectomy still is a standard procedure for the treatment of advanced laryngeal or hypopharyngeal carcinoma. The unavoidable loss of voice may lead to serious impairments in quality of life. The most common technique of voice restoration is the tracheal-esophageal puncture combined with the application of a voice prosthesis. Laryngeal reconstruction with a radial forearm flap represents a possible surgical method of voice restoration. This study is a mono-center retrospective analysis of patients receiving a so-called laryngoplasty after total laryngectomy between 2006 and 2015, focusing on long-term functional outcome and complications. 39 patients were included. Sufficient phonation was possible in 77 %, finger-free speaking was achieved in 62 %. Exclusion of irradiated patients revealed a rehabilitation rate of 91 %. The most common early complication was cervical hematoma in 15 %, whereas no loss of flap was assessed. Stenosis of the laryngoplasty was seen in 7 cases, mainly post-irradiation. The rate of successful voice restoration is equal in both, laryngoplasty and voice prosthesis patients. However, voice quality is better after surgical reconstruction. Complications induced by the voice prosthesis, which may be severe in some cases, were not seen in the study group. Furthermore, life-long support by an ENT specialist regarding voice prosthesis exchange is not necessary. Assuming correct choice of candidates, laryngoplasty is a sufficient method for voice restoration after laryngectomy.

Clinical Assessment of Reconstruction Involving Gastric Pull-Up Combined with Free Jejunal Graft After Total Pharyngolaryngoesophagectomy.

BACKGROUND: Total pharyngolaryngoesophagectomy (PLE) is used as a curative treatment for synchronous laryngopharyngeal and thoracic esophageal cancer or for multiple cancers in the cervical and thoracic esophagus. Gastric pull-up is commonly used after PLE, but postoperative complications are common. The present study evaluated these procedures in patients with esophageal cancer. METHODS: Fourteen patients (7 with synchronous pharyngeal and thoracic esophageal cancer, 4 with synchronous cervical and thoracic esophageal cancer, and 3 with cervicothoracic esophageal cancer) underwent reconstructive surgery after PLE involving gastric pull-up combined with free jejunal graft between 2004 and 2015. RESULTS: Esophagectomy via right thoracotomy was performed in 9 patients, and transhiatal esophagectomy was used in 5. The posterior mediastinal route was used in 13 patients, excluding one patient with early gastric cancer. Interposition of a free jejunal graft included microvascular anastomosis using two arteries and two veins in all patients. Anastomotic leakage and graft necrosis did not occur in any of the 14 patients who underwent the above surgical procedures. Tracheal ischemia close to the tracheostomy orifice occurred in 4 patients (28.6%), but none of these patients developed pneumonia. No hospital deaths were recorded. CONCLUSIONS: The results indicate that gastric pull-up combined with free jejunal graft is a feasible reconstructive surgery after PLE. This procedure is a promising treatment strategy for synchronous pharyngeal and thoracic esophageal cancer or multiple cancers in the cervical and thoracic esophagus. Larger series are needed to show the distinct advantages of this procedure in comparison with conventional methods of reconstruction after PLE.