Can Loupe magnification be a viable alternative to Operative Microscope magnification for vascular anastomosis in reconstructive surgery? A systematic review and meta-analysis

PURPOSE

The aim of this study is to compare the outcomes of vascular anastomosis using loupes magnification versus operative microscope magnification in reconstructive surgery.

METHODS

We performed a systematic review of MEDLINE (via PubMed), Scopus and Cochrane Library database according to the PRISMA guidelines. Comparative studies between the two techniques and single arm studies reporting on loupes reconstruction were included. Random-effects model meta-analyses were performed.

RESULTS

Twelve studies, reporting a total of 3908 of flaps, 3409 of which were performed under loupes magnification and 499 under the operative microscope magnification were selected for analysis. No statistically significant differences were observed regarding total flap loss and vascular complication between the two arms. In the Loupes group the rate of total flap loss was 2.65% (95% CI: 1.15-4.63) and the rate of vascular complications 4.49% (95% CI: 2.58-6.84).

CONCLUSION

Loupes magnification under circumstances can provide a safe and effective alternative to microvascular reconstruction in reconstructive surgery. With respect to flap failure and vascular complication rates, there appear to be no statistically significant differences between the anastomoses conducted under Loupes magnification and the standard operative microscope.

Acetylsalicylic Acid is Not Associated With Improved Clinical Outcomes After Microsurgical Breast Reconstruction

INTRODUCTION

Microvascular thrombosis with resultant flap loss remains a devastating complication in autologous breast reconstruction. While acetylsalicylic acid (ASA) for prevention of microvascular thrombosis is commonly administered postoperatively, clinical evidence supporting this practice remains insufficient. Here, we investigate the association of postoperative ASA administration with differences in clinical outcomes following microsurgical breast reconstruction.

METHODS

A prospectively maintained database was queried to identify patients who had undergone microsurgical breast reconstruction. Patients were categorized based on whether they had received postoperative ASA for 30 d (Group 1) or had not received ASA (Group 2). Patient demographics, reconstructive outcomes, complications, and transfusion requirements were retrieved.

RESULTS

One hundred thirty six patients with a mean age of 49.5 y and a mean body mass index of 28.5 kg/m² who had undergone a total of 216 microsurgical breast reconstructions were included. No significant differences were noted with regard to patient demographics with the exceptions of increased rates of neoadjuvant chemotherapy and delayed reconstruction in Group 1. There were no significant differences in the rates of postoperative complications including breast hematoma, mastectomy skin flap necrosis, partial flap necrosis, seroma, and deep venous thrombosis between patients who did or did not receive ASA postoperatively. Similarly, no difference was noted regarding postoperative blood transfusion rates (Group 1: 9.9% versus Group 2: 9.1%; P = 0.78). Finally, patients in Group 1 had significantly longer hospital stays (Q1 = 4, median = 4.5, Q3 = 5).

CONCLUSIONS

Postoperative ASA administration is not associated with improved postoperative clinical outcomes. The use of ASA routinely after autologous breast reconstruction does not appear to be a necessity in practice.

[The conjoined latissimus dorsi and parascapular free flap for reconstruction of extensive soft tissue defects]

OBJECTIVE

Durable and resilient soft tissue reconstruction of vast defects of the extremities or the torso.

INDICATIONS

Reconstruction of disproportionately large defects, particularly in cases of simultaneous bone and joint reconstruction.

CONTRAINDICATIONS

History of surgery or irradiation of upper back and axilla, impossibility of surgery under lateral positioning; relative contraindications in wheelchair users, hemiplegics, or amputees.

SURGICAL TECHNIQUE

General anesthesia and lateral positioning. First, the parascapular flap is harvested, with the initial skin incision made medially in order to identify the medial triangular space and the circumflex scapular artery. Flap raising then proceeds from caudal to cranial. Second, the latissimus dorsi is harvested, with the lateral border being dissected free first, before the thoracodorsal vessels are visualized on its undersurface. Flap raising then proceeds from caudal to cranial. Third, the parascapular flap is advanced through the medial triangular space. If the circumflex scapular and thoracodorsal vessels originate separately from the subscapular axis, an in-flap anastomosis is warranted. Subsequent microvascular anastomoses should be performed outside the zone of injury, typically in an end-to-end fashion of the vein and end-to-side fashion of the artery.

POSTOPERATIVE MANAGEMENT

Postoperative anticoagulation with low-molecular-weight heparin under anti-Xa monitoring (semitherapeutic in normal-risk and therapeutic in high-risk cases). Hourly clinical assessment of flap perfusion for 5 consecutive days, followed by stepwise relaxation of immobilization and commencement of dangling procedures in cases of lower extremity reconstruction.

RESULTS

Between 2013 and 2018, 74 conjoined latissimus dorsi and parascapular flaps were transplanted to cover vast defects of the lower (n = 66) and upper extremity (n = 8). The mean defect size was 723 ± 482 cm² and the mean flap size was 635 ± 203 cm². Eight flaps required in-flap anastomoses for separate vascular origins. There was no case of total flap loss.

Post-reconstruction Free Flap Complications After Oral Cancer Ablation

Introduction

Microvascular free flap transfer is considered a standard reconstruction after the ablation of oral cancer. Although the success rate is high, flap complications occasionally occur. This study investigated the reasons for and local factors involved in complications of free flap transfer and explored how to salvage the flaps.

Patients and Methods

The cases of 53 patients who underwent a free flap transfer [radial forearm flaps (n = 36), abdominis musculocutaneous flaps (n = 6), scapular osteocutaneous flaps (n = 10), and fibular osteocutaneous flap (n = 1)] were analyzed: flap complications were observed in five of the cases.

Results

In the all five cases, a salvage operation was performed under general anesthesia. The flap complications occurred within 33 h after anastomosis. In the salvage operation, thrombotic occlusion in veins of flap feeders was observed in three of the five cases. The possible reasons for flap complications were a twisting of the anastomosed vein where two veins were united, pressure to the feeder due to subcutaneous hematoma, and edema of adjacent tissue and/or drain tube; the reason was not clear in one case. The flaps were successfully salvaged in four cases by thrombectomy in veins, release of pressure at the veins, and/or interposition of the vein graft.

Conclusion

Surgeons should pay close attention to the pressure and/or twisting in the feeder as well as the hemostasis in the surgical field, and a salvage operation should be carried out immediately when a flap complication is identified.

Autologous Mandible Reconstruction in a Hypercoagulable Patient following Multiple Failed Free Flaps

Coagulopathies affect 3% of free flap patients and are among the leading causes of free flap failure. This report describes the case of a head and neck cancer patient that experienced two remote free flap failures before successful autologous mandibular reconstruction. Following identification of an unrecognized thrombophilic state, a focused anticoagulation strategy was executed, including an intraoperative heparin drip, stringent postoperative maintenance of Factor Xa levels between 0.3 and 0.5 IU per mL, and transition to an outpatient enoxaparin regimen of 1 mg per kg twice daily for 1.5 months following surgery. Here, we demonstrate that free tissue transfer following multiple previous failed attempts in the setting of hypercoagulability remains a viable reconstructive option with close interdisciplinary collaboration, close clinical monitoring, and patient-specific antithrombotic protocols.

Flexible Doppler ultrasound device for the monitoring of blood flow velocity

Thrombosis and restenosis after vascular reconstruction procedures may cause complications such as stroke, but a clinical means to continuously monitor vascular conditions is lacking. Conventional ultrasound probes are rigid, particularly for postoperative patients with fragile skin. Techniques based on photoplethysmography or thermal analysis provide only relative changes in flow volume and have a shallow detection depth. Here, we introduce a flexible Doppler ultrasound device for the continuous monitoring of the absolute velocity of blood flow in deeply embedded arteries based on the Doppler effect. The device is thin (1 mm), lightweight (0.75 g), and skin conforming. When the dual-beam Doppler method is used, the influence of the Doppler angle on the velocity measurement is avoided. Experimental studies on ultrasound phantoms and human subjects demonstrate accurate measurement of the flow velocity. The wearable Doppler device has the potential to enhance the quality of care of patients after reconstruction surgery.

Hepatitis C as a Potential Risk Factor for Adverse Surgical Outcomes in Head and Neck Free Tissue Transfer Reconstruction

Background: Infection with hepatitis C virus (HCV) is associated with an increased risk of developing head and neck cancer (HNC), and negatively impacts cancer-specific survival. Objective: To measure the impact of HCV status on free tissue transfer failure, flap takeback, and length of stay in HNC patients undergoing reconstruction. Methods: We retrospectively reviewed patients who underwent head and neck free tissue transfer reconstruction at a single academic institution between August 2011 and June 2020. Results: In the HCV-infected group, total flap failure rate was 2.9% versus 1.3% in the control group and the takeback rate was 11.1% versus 9.6%. On multivariate analysis, HCV status was not associated with flap failure, flap takeback, or total length of hospital stay >7 days. Conclusion: In this study, HCV status was not associated with differences in postoperative complications or length of stay. Future research with greater numbers of HCV-positive study subjects is required to elucidate the effect of HCV infection in this patient population.

Outcomes in Head and Neck Free Flap Reconstruction Among Patients With a History of Venous Thromboembolism

OBJECTIVE

To investigate if a history of venous thromboembolism (VTE) is a risk factor for complications in head and neck free flap surgery by assessing outcomes among patients with a history of deep vein thrombosis (DVT) and/or pulmonary embolism (PE).

STUDY DESIGN

Retrospective cohort study.

SETTING

Single tertiary care center.

METHODS

All patients undergoing head and neck free flap reconstruction at our institution between September 1, 2006, and April 2, 2020, were assessed for inclusion. Patients with and without a history of DVT or PE preoperatively were identified and grouped for comparison. Groups were compared for demographics, comorbidities, and 30-day complications. Significance was assessed with chi-square and binary logistic regression analyses.

RESULTS

Of the 1061 patients meeting inclusion criteria, 40 (3.8%) had a history of VTE. These patients were significantly older (mean [SD], years: 67.8 [11.7] vs 63.0 [14.1], P = .038) and significantly more likely to have history of chemotherapy (35.0% vs 18.7%, P = .010) and stroke (27.5% vs 4.5%, P < .001). After accounting for patient characteristics via binary logistic regression, VTE was independently associated with an increased risk for postoperative thrombosis of the free flap pedicle (odds ratio [95% CI] = 3.65 [1.12-11.90], P = .032) and reoperation (2.45 [1.25-4.80], P = .009). Patients with history of PE had a significantly increased risk for flap failure (7.70 [1.77-33.52], P = .007). Prior VTE was not independently associated with an increased risk for medical complications or readmission.

CONCLUSION

Patients with a history of VTE may be at an increased risk for free flap compromise secondary to postoperative pedicle thrombosis. This risk should be considered in preoperative workup and postoperative monitoring.

Are venous thromboembolism risk assessment tools reliable in the stratification of microvascular risk following lower extremity reconstruction?

Introduction

The incidence of flap failure is significantly higher in the lower extremity compared to free tissue transfer in the head, neck and breast. The most common cause of flap failure is venous thrombosis. The aim of this study was to assess the reliability of venous thromboembolism (VTE) risk assessment tools in this high-risk cohort and to assess the ability of such tools to identify patients at risk of developing microvascular venous thrombosis and venous thromboembolism following lower extremity free flap reconstruction.

Methods

A single centre retrospective cohort study was conducted between August 2012-August 2019. Adult patients who had undergone free tissue transfer following open lower extremity fractures were eligible for inclusion. All patients were retrospectively risk assessed using the Department of Health (DoH), Modified Caprini and Padua VTE risk assessment tools.

Results

Fifty-eight patients were included; all were at high risk of DVT according to the DoH (mean score ± SD, 3.7 ± 0.93), Caprini (10.2 ± 1.64) and Padua (5.4 ± 0.86) risk assessment tools. All patients received appropriate thromboprophylaxis; the incidence of symptomatic hospital acquired VTE was 3.5%. Micro-anastomotic venous thrombosis occurred in 4 patients resulting in one amputation. Partial flap necrosis occurred in 7 patients. There were no significant differences in scaled Caprini (median score, 10 vs 9, z = 1.289, p = 0.09), DoH (3 vs 3, z = 0.344, p = 0.36), and Padua (5 vs 5.5, z= -0.944, p = 0.17) scores between those with and without microvascular venous thrombosis.

Conclusion

This data suggests that current VTE risk assessment tools do not predict risk of microvascular venous thrombosis following lower extremity reconstruction. Further prospective studies are required to optimise risk prediction models and thromboprophylaxis use in this cohort.

The Influence of Topically Administered Heparin on Peripheral Microcirculation of the Skin: A Double-Blind, Randomized, Controlled Preliminary Study on 50 Healthy Subjects

BACKGROUND

 Venous thrombosis is the most common cause of flap failure in the first days after surgery. Although heparin is one of the most important antithrombotic substances and is implemented in the therapy of various diseases, there are only a few studies addressing its topical administration in the field of flap surgery. Especially, very little is known about the effects of topical heparin and its impact on microcirculation. In this study we evaluated to what extent topically administered heparin influences skin microcirculation (capillary venous oxygen saturation SO2, blood filling of microvessels, blood flow, and velocity) in healthy subjects.

METHODS

 Skin perfusion parameters on the forearm were measured with the O2C device in a double-blinded, controlled, and randomized study with 50 healthy subjects after administration of heparin ointment in three different concentrations and a control ointment (dexpanthenol).

RESULTS

 Topically administrated heparin slightly increased SO2 (max. 187 ± 285 SD or standard deviation % vs. 145 ± 129 SD %), flow (max. 264 ± 427 SD % vs. 151.74 ± 111 SD %), and velocity (max. 153 ± 149 SD % vs. 122 ± 56 SD %) after an incubation time of 60 minutes in comparison to control. No statistically significant difference could be detected regarding heparin concentration.

CONCLUSION

 As a first important step in possible future implementing of heparin as a topical administration in flap surgery, our data-although not statistically significant-indicate that heparin can improve microcirculation (SO2, flow) in healthy subjects. Nevertheless, further research in subjects with impaired microcirculation is necessary.

Biomedical Applications of Bacteria-Derived Polymers

Plastics have found widespread use in the fields of cosmetic, engineering, and medical sciences due to their wide-ranging mechanical and physical properties, as well as suitability in biomedical applications. However, in the light of the environmental cost of further upscaling current methods of synthesizing many plastics, work has recently focused on the manufacture of these polymers using biological methods (often bacterial fermentation), which brings with them the advantages of both low temperature synthesis and a reduced reliance on potentially toxic and non-eco-friendly compounds. This can be seen as a boon in the biomaterials industry, where there is a need for highly bespoke, biocompatible, processable polymers with unique biological properties, for the regeneration and replacement of a large number of tissue types, following disease. However, barriers still remain to the mass-production of some of these polymers, necessitating new research. This review attempts a critical analysis of the contemporary literature concerning the use of a number of bacteria-derived polymers in the context of biomedical applications, including the biosynthetic pathways and organisms involved, as well as the challenges surrounding their mass production. This review will also consider the unique properties of these bacteria-derived polymers, contributing to bioactivity, including antibacterial properties, oxygen permittivity, and properties pertaining to cell adhesion, proliferation, and differentiation. Finally, the review will select notable examples in literature to indicate future directions, should the aforementioned barriers be addressed, as well as improvements to current bacterial fermentation methods that could help to address these barriers.

Linking Labile Heme with Thrombosis

Thrombosis is one of the leading causes of death worldwide. As such, it also occurs as one of the major complications in hemolytic diseases, like hemolytic uremic syndrome, hemorrhage and sickle cell disease. Under these conditions, red blood cell lysis finally leads to the release of large amounts of labile heme into the vascular compartment. This, in turn, can trigger oxidative stress and proinflammatory reactions. Moreover, the heme-induced activation of the blood coagulation system was suggested as a mechanism for the initiation of thrombotic events under hemolytic conditions. Studies of heme infusion and subsequent thrombotic reactions support this assumption. Furthermore, several direct effects of heme on different cellular and protein components of the blood coagulation system were reported. However, these effects are controversially discussed or not yet fully understood. This review summarizes the existing reports on heme and its interference in coagulation processes, emphasizing the relevance of considering heme in the context of the treatment of thrombosis in patients with hemolytic disorders.

Microsurgical Salvage of Acute Lower Limb Ischemia after Iatrogenic Femoral Injury during Orthopedic Surgery in a Pediatric Patient

Acute lower limb ischemia (ALLI) in the pediatric population is rare but may lead to limb loss and life-long complications. We report the technique and outcomes of microsurgical salvage of ALLI in a preterm newborn after open reduction of congenital hip dysplasia. A 2-month-old girl was born premature at week 36 with congenital bilateral hip dysplasia. The initial management attempted was conservative and entailed placement of bilateral Von Rosen splints. The treatment was successful on the left side, but the patient had recurrent unstable hip dislocation on the right side. Subsequently, 2 attempts at close reduction under general anesthesia were done and both were unsuccessful in maintaining the right hip in the acetabulum. Therefore, an open reduction of the right hip was planned through a medial/obturator approach. During the surgical procedure, the neurovascular femoral bundle (including the superficial femoral artery [SFA], femoral vein [FV], and femoral nerve) was accidently transected with subsequent development of ALLI. Therefore, the FV was harvested distally to the injury site and a 4-cm long healthy segment was obtained. It was reversed, flushed with heparin, spatulated at both extremities, and interposed to the SFA in end-to-end fashion using two 9/0 polypropylene interrupted sutures under microscope. Reperfusion of the limb was noted immediately after releasing the vascular clamps. The final ischemia time at completion of the surgical procedure was 6 hr. Thereby, prophylactic 4-compartment fasciotomies were performed in the right leg. The patient tolerated the procedure well and the postoperative clinical course was free from adverse events. Duplex ultrasound examination at 6 weeks after the intervention confirmed sustained clinical success and showed no signs of venous thromboembolism. At the same time, X-ray examination of the right hip confirmed adequate and stable reduction of the joint in the acetabulum. ALLI due to accidental arterial injury during orthopedic surgical procedures for congenital defects in newborns is a rare but potentially devastating complication. Microsurgical salvage is a safe, feasible, and effective option to restore limb flow. Multidisciplinary expertise and meticulous technique are mandatory in order to achieve satisfactory and durable outcomes.

New techniques and recommendations in the management of free flap surgery for head and neck defects in cancer patients

Free flap surgery is the gold standard surgical treatment for head and neck defects in cancer patients. Outcomes have improved considerably, probably due to recent advances in surgical techniques. In this article, we review improvements in the parameters traditionally used to optimize hematocrit levels and body temperature and to prevent vasoconstriction, and describe the use of cardiac output-guided fluid management, a technique that has proved useful in other procedures. Finally, we review other parameters used in free flap surgery, such as clotting/platelet management and nutritional optimization.

Utilization of microvascular couplers in salvage arterial anastomosis in head and neck free flap surgery: Case series and literature review

BACKGROUND

In microvascular reconstruction of ablative oncologic defects, coupler devices have traditionally been used for venous anastomosis, whereas the arterial anastomosis is hand-sewn. In the setting of repeated intraoperative arterial anastomotic thrombosis, a coupler device may be of use in reducing the risk of rethrombosis.

METHODS

Two patients were seen with advanced stage head and neck cancer and underwent oncologic resection. During microvascular reconstruction, a clot at the arterial anastomosis was encountered in both cases.

RESULTS

After starting therapeutic anticoagulation and attempting unsuccessful suture reanastomosis, coupler devices were used for arterial anastomosis, resulting in viable free-tissue transfer.

CONCLUSIONS

Although traditionally used for venous anastomosis, coupler devices may serve a purpose in the salvage setting when facing repeated intraoperative arterial thrombosis.

An inhibitor of myosin II, blebbistatin, suppresses development of arterial thrombosis

Arterial thrombosis (AT) causes various ischemia-related diseases, which impose a serious medical burden worldwide. As an inhibitor of myosin II, blebbistatin has an important role in thrombosis development. We investigated the effect of blebbistatin on carotid artery ligation (CAL)-induced carotid AT and its potential underlying mechanism. A model of carotid AT in mice was generated by CAL. Mice were divided into three groups: CAL model, blebbistatin-treated, and sham-operation. After 7 days, blood vessels were harvested from mice in each group. The procoagulant activity of tissue factor (TF) was tested by a chromogenic assay, and thrombus severity assessed by histopathology scores. Expression of non-muscle myosin heavy chain II A (NMMHCIIA), TF, glycogen synthase kinase 3β (GSK3β), and nuclear factor-kappa B (NF-κB) was detected by immunohistochemical and immunofluorescence staining. mRNA expression was measured by quantitative polymerase chain reaction. Blebbistatin (1 mg/kg) inhibited development of carotid AT, reduced infiltration of inflammatory cells, and prevented vascular-tissue damage, relative to the model group. Furthermore, blebbistatin also reduced the procoagulant activity of TF. Immunohistochemical and immunofluorescence data demonstrated that, compared with the model group, blebbistatin intervention reduced expression of NMMHCIIA, TF, GSK3β, p65, and p-p65 in carotid-artery endothelia in the CAL-induced AT model, but it increased levels of p-GSK3β. Blebbistatin could inhibit expression of NMMHCIIA mRNA in the CAL model. Overall, our data demonstrated that blebbistatin could inhibit TF expression and AT development in arterial endothelia (at least in part) via GSK3β/NF-κB signaling.

Image-Guided Percutaneous Gastrostomy Tube Placement is Safe in Patients Requiring Aspirin 325 mg

RATIONALE AND OBJECTIVES

Requests for gastrostomy tube placement in patients on aspirin (ASA) 325 mg are common, particularly in patients following reconstructive surgery for head and neck cancer, but periprocedural guidelines and recommendations regarding management of high dose aspirin are inconsistent. The purpose of this study was to assess the bleeding risk of percutaneous gastrostomy tube placement in patients on ASA 325 mg.

MATERIALS AND METHODS

This retrospective study of 213 patients who underwent image-guided "push" percutaneous gastrostomy tube placement compared rates of significant bleeding and other secondary outcomes (including all-cause mortality within 30 days, procedure-related mortality, bowel perforation, abdominal abscess, peritonitis, aspiration pneumonia, intraprocedural airway complications, and tube dislodgement) between patients maintained on ASA 325 mg and patients not on antiplatelet or anticoagulation therapy.

RESULTS

No significant bleeding episodes occurred in patients on ASA 325 mg, compared to three episodes in patients not on ASA 325 mg (p = 0.37). A patient in each group had aspiration pneumonia possibly related to tube placement. There were no other notable secondary outcomes, including intraprocedural airway complications in this population with complex head and neck anatomy.

CONCLUSION

These findings suggest that holding ASA 325 mg in patients undergoing percutaneous gastrostomy tube placement is not necessary, especially in patients in whom holding ASA would pose considerable risk. Further multi-institutional longitudinal study is warranted to validate these results.

Angiogenesis and tissue formation driven by an arteriovenous loop in the mouse

The rapid vascularisation of biomaterials and artificial tissues is a key determinant for their in vivo viability and ultimately for their integration in a host; therefore promoting angiogenesis and maintaining the newly formed vascular beds has become a major goal of tissue engineering. The arteriovenous loop (AVL) has been an extensively studied platform which integrates microsurgery with cells scaffolds and growth factors to form neotissues. Most AVL studies to date are limited to larger animal models, which are surgically easier to perform, but have inherent limits for the understanding and interrogation of the underlying in vivo mechanisms due the paucity of transgenic models. Here, we demonstrate for the first time in a mouse model the utility of the AVL in the de novo production of vascularized tissue. We also present the combined use of the model with 3D printed chambers, which allow us to dictate size and shape of the tissues formed. This novel platform will allow for an understanding of the fundamental mechanisms involved in tissue generation de novo.

Effect of goal-directed haemodynamic therapy in free flap reconstruction for head and neck cancer

BACKGROUND

In free flap reconstruction for head and neck cancer, achieving a haemodynamic target using excessive fluid infusion is associated with decreased flap survival rates and extended hospital stays. We hypothesized that goal-directed haemodynamic therapy would improve flap survival rates and shorten hospitalization periods.

METHODS

Patients scheduled for free flap reconstruction were randomly assigned to a goal-directed haemodynamic therapy group (n = 31) or a conventional haemodynamic therapy control group (n = 31). The control group received extra bolus fluid and ephedrine or norepinephrine to maintain a mean arterial pressure ≥ 65 mmHg. The goal-directed haemodynamic therapy group received a colloid solution as the extra bolus fluid to maintain a stroke volume variation < 12%; dobutamine, ephedrine, or norepinephrine was administered to maintain a cardiac index ≥ 2.5 l/min/m² and mean arterial pressure ≥ 65 mmHg. Enhanced recovery after surgery protocols were not used except for fluid therapy. An otolaryngologist blinded to group assignments assessed flap outcomes and classified them as 'survival,' 'at risk' or 'failure.'

RESULTS

The hospitalization period was not significantly different between the groups. The goal-directed haemodynamic therapy group had significantly shorter intensive care unit stays and a higher flap survival rate. The crystalloid volume was significantly lower in goal-directed haemodynamic therapy group. Reoperation rates, post-operative complications, and laboratory data including inflammatory markers were similar between the groups.

CONCLUSION

Compared to conventional haemodynamic therapy, goal-directed haemodynamic therapy does not reduce hospitalization periods; it may, however, reduce the length of intensive care unit stays and increase flap survival rates. Further studies including multi-centre trials with larger sample sizes are warranted.

Free flap surgery in Europe: an interdisciplinary survey

Free flap surgery is essential for the aesthetic and functional reconstruction of various parts of the body. The aim of this study was to compare current concepts of perioperative flap management between ENT, craniomaxillofacial, and plastic surgeons. A European survey was conducted among 570 surgical departments, covering all aspects of free flap surgery. Focus was placed on antibiotic and antithrombotic drug use, aspects of osseous reconstruction, and flap monitoring strategies. One hundred and seventy-two medical units participated. A broad spectrum of anticoagulant regimens and a trend towards prolonged antibiotic prophylaxis were found. Fixation with (CAD/CAM) reconstruction plates was more popular than monocortical locking with miniplates in the mandible. Visual assessment and Doppler systems were reported to be the most common monitoring modalities. The flap loss rate was stated to be higher after osseous reconstruction. Only a few differences in perioperative flap management were identified between the different surgical fields, and osseous reconstruction appears to be the most challenging.

The Efficacy of Dextran-40 as a Venous Thromboembolism Prophylaxis Strategy in Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

The incidence of venous thromboembolism (VTE) in peritoneal malignancies can approach 30 to 50 per cent without prophylaxis. Prophylaxis in cytoreductive surgeries (CRS) presents a challenge to preoperative heparin-based therapy because of an increased risk of coagulopathy and potential for bleeding. Herein, we report the large series of CRS and hyperthermic intraperitoneal chemotherapy receiving dextran-40 prophylaxis. Retrospective chart review of peritoneal malignancies patients undergoing CRS at University of Nebraska Medical Center identified 69 individuals who received dextran-40 between 2010 and 2013. The incidences of VTEs, perioperative bleeding, complications, morbidity, and mortality were determined in-hospital and at 90 days. Of the 69 patients treated, the 30-day VTE rate was 8.7 per cent, and no pulmonary embolisms, bleeding, anaphylactoid reaction, or mortality were observed with dextran usage. The specific VTE events included three upper extremity and three lower extremity VTEs. No additional VTE events were identified between 30 and 90 days. In conclusion, dextran-40 prophylaxis was not associated with any perioperative bleeding events, and the observed incidence of VTE was comparable to reported heparin-based prophylaxis in CRS/hyperthermic intraperitoneal chemotherapy patients. This data supports further exploration of dextran-40 as a VTE prophylactic agent in complex surgical oncology cases.

Comparison of Video and In-person Free Flap Assessment following Head and Neck Free Tissue Transfer

Objective

Compare the efficiency of remote telehealth flap assessments with traditional in-person flap assessments.

Study Design

Observational study with retrospective review.

Setting

Tertiary academic medical center.

Subjects and Methods

All patients undergoing head and neck free tissue transfer were included in the study. All patients whose surgery was performed at hospital A underwent an in-person flap check overnight. Those at hospital B received a remote flap assessment. The primary outcome was total time spent performing the midnight flap assessment, including travel time. Data were gathered prospectively using an online survey.

Results

Sixty consecutive patients met inclusion criteria. On the night of the surgery, 31 had an in-person flap check while 29 had a video telehealth flap check. There were no partial or total flap losses or take-backs resulting from the flap checks. Mean (SD) times for in-person and remote assessments were 34 (16) minutes (range, 10-60 minutes) and 13 (8) minutes (range, 5-35 minutes), respectively ( P < .001). House staff unanimously felt the remote telehealth system improved their quality of life without affecting their perception of the quality of the flap assessment ( P = .001).

Conclusion

Compared with in-person flap assessments in this cohort, telehealth assessments allowed more efficient examination of free tissue reconstructions while yielding seemingly equivalent information. Therefore, remote telehealth flap checks may provide useful information supporting the use of high-fidelity remote data-streaming technology in the delivery of complex care to patients distant from their care provider.

Coulomb nanoradiator-mediated, site-specific thrombolytic proton treatment with a traversing pristine Bragg peak

Traversing proton beam-irradiated, mid/high-Z nanoparticles produce site-specific enhancement of X-ray photon-electron emission via the Coulomb nanoradiator (CNR) effect, resulting in a nano- to micro-scale therapeutic effect at the nanoparticle-uptake target site. Here, we demonstrate the uptake of iron oxide nanoparticles (IONs) and nanoradiator-mediated, site-specific thrombolysis without damaging the vascular endothelium in an arterial thrombosis mouse model. The enhancement of low-energy electron (LEE) emission and reactive oxygen species (ROS) production from traversing proton beam-irradiated IONs was examined. Flow recovery was only observed in CNR-treated mice, and greater than 50% removal of the thrombus was achieved. A 2.5-fold greater reduction in the thrombus-enabled flow recovery was observed in the CNR group compared with that observed in the untreated ION-only and proton-only control groups (p < 0.01). Enhancement of the X-ray photon-electron emission was evident from both the pronounced Shirley background in the electron yield and the 1.2- to 2.5-fold enhanced production of ROS by the proton-irradiated IONs, which suggests chemical degradation of the thrombus without potent emboli.

Functioning free muscle transfer for the restoration of elbow flexion in brachial plexus injury patients

BACKGROUND

Restoration of elbow function in traumatic brachial plexus injury patients remains the priority in the reconstruction of the involved extremity. In cases of complete nerve root injuries and in delayed cases, the only option for elbow reconstruction is the functional free muscle transfer. The purpose of this paper was to present the clinical outcomes and complications of functioning free muscle transfers using the gracilis muscle for the restoration of elbow flexion in brachial plexus injury patients in a tertiary institution from January 1, 2005 to January 31, 2014.

PATIENT AND METHODS

A retrospective review of all patients who had functioning free muscle transfers for elbow flexion was done with a minimum of 12 months follow-up. Outcome measures were elbow flexion in terms of range of motion in degrees, muscle strength of the transferred muscle, VAS (visual analogue scale) for pain, postoperative DASH scores and complications of the procedure.

RESULTS

There were 39 males and three females. The average age at the time of surgery was 28.6 (SD, 8.5) years. The average delay to surgery was 16 months (range, 3-120 months). The flap success rate for viability was achieved in 38 of 42 patients. The average follow-up for the 38 patients was 30 months (range, 12-103 months, SD 19 months). Success rate of at least M3/5 muscle strength was achieved in 37 of 42 patients with an average range of elbow flexion of 107° (SD, 20.4°). The average post-operative VAS for pain was 3.6 (SD, 3.0). The average post-operative DASH score was 43.09 (SD, 14.9). There were a total of 10 minor complications and five major complications.

CONCLUSION

Functioning free muscle transfer using the gracilis muscle was a reliable procedure in the restoration of elbow flexion in patients with incomplete brachial plexus injury treated beyond 6 months from the time of injury and in patients with complete injuries.

Peroneal artery-vein index as a potential factor of thrombosis occurrence in free osteocutaneous fibula flap

BACKGROUND

Despite high popularity and great success rates of free osteocutaneous fibula flaps, the flap failure caused by vascular thrombosis is still a challenging problem. The authors present their evaluation of a potential thrombosis risk factor - a peroneal artery-vein index.

METHODS

The authors evaluated the diameters of peroneal vessels and peroneal artery-vein indexes based on the computed tomography angiographies in 10 patients who underwent a mandible reconstruction with a free fibula flap and compared the results with clinical outcome.

RESULTS

In one case the flap was lost, because of thrombosis in the donor vein. This patient presented superficial varicose veins of both lower extremities. Peroneal vein diameters in this patient ranged from 5,05 mm to 6,68 mm and were higher than in patients without complications. The peroneal artery-vein index in the patient with thrombosis ranged from 0,37 to 0,50 with median 0,40 and was lower than in patients without complications.

CONCLUSIONS

High disproportion between peroneal artery and concomitant veins might be a potential risk factor of the occurrence of venal thrombosis. Detailed perioperative examination of peroneal veins in patients with varicosities should be considered.

Testing a New Anticoagulation Method for Free Flap Reconstruction of Head and Neck Cancers

Objectives

Free flaps are widely used to reconstruct head and neck defects. Despite the improvement in the surgical techniques and the surgeons’ experiences, flap failures still occur due to thrombotic occlusion after small vessels anastomosis. To reduce the possibility of flap loss as a result of thrombotic occlusion, various anticoagulants have been used. In this study we decided to evaluate a new protocol for anticoagulation therapy and its effect on flap survival and complications.

Methods

In this interventional study, 30 patients with head and neck cancer underwent surgical defects were reconstructed by microvascular free flap between 2013 and 2014. In the postoperative period patients have taken aspirin (100 mg/day) for 5 days and enoxaparin (40 mg/day subcutaneously) for 3 days. The flap survival was followed for three weeks.

Results

Given that there was no complete necrosis or loss of flap, the free flap success rate was as much as 100%. The need for re-exploration occurred in 3 patients (10%). Only in one patient the need for re-exploration was due to problem in venous blood flow.

Conclusion

The aspirin-enoxaparin short-term protocol may be a good choice after free flap transfer in reconstruction of head and neck surgical defects.

Controversies in the use of hydroxyethyl starch solutions in small animal emergency and critical care

OBJECTIVES

To (1) review the development and medical applications of hydroxyethyl starch (HES) solutions with particular emphasis on its physiochemical properties; (2) critically appraise the available evidence in human and veterinary medicine, and (3) evaluate the potential risks and benefits associated with their use in critically ill small animals.

DATA SOURCES

Human and veterinary original research articles, scientific reviews, and textbook sources from 1950 to the present.

HUMAN DATA SYNTHESIS

HES solutions have been used extensively in people for over 30 years and ever since its introduction there has been a great deal of debate over its safety and efficacy. Recently, results of seminal trials and meta-analyses showing increased risks related to kidney dysfunction and mortality in septic and critically ill patients, have led to the restriction of HES use in these patient populations by European regulatory authorities. Although the initial ban on the use of HES in Europe has been eased, proof regarding the benefits and safety profile of HES in trauma and surgical patient populations has been requested by these same European regulatory authorities.

VETERINARY DATA SYNTHESIS

The veterinary literature is limited mostly to experimental studies and clinical investigations with small populations of patients with short-term end points and there is insufficient evidence to generate recommendations.

CONCLUSIONS

Currently, there are no consensus recommendations regarding the use of HES in veterinary medicine. Veterinarians and institutions affected by the HES restrictions have had to critically reassess the risks and benefits related to HES usage based on the available information and sometimes adapt their procedures and policies based on their reassessment. Meanwhile, large, prospective, randomized veterinary studies evaluating HES use are needed to achieve relevant levels of evidence to enable formulation of specific veterinary guidelines.

Behavior of anastomozed vessels and transferred flaps after anastomosed site infection in head and neck microsurgical reconstruction

OBJECTIVE

This report evaluates the behavior of anastomosed vessels and transferred flaps after anastomosed site infection in head and neck reconstruction.

PATIENTS AND METHODS

Eleven free-flap cases after infection at the vascular pedicle site were included, the patency of which was observed macroscopically after re-exploration and pus drainage. Location was in the tongue (5 cases), oropharynx (3 cases), mouth floor (1 case), mandible (1 case), and hypopharynx (1 case). Transferred flaps originated from rectus abdominis (3 cases), anterolateral thigh (3 cases), radial forearm (3 cases), jejunum (1 case), and latissimus dorsi (1 case). Days for infection found were ranged 3-14 days postoperatively. Causes of infection were the salivary fistula formation in 5 cases, and precise etiology was not defined in the other 6 cases.

RESULTS

Disruption of the vascular pedicles occurred with high frequency after infection. Disruption of vein occurred most frequently (5 cases), followed by both artery and vein (2 cases) and artery only (1 case). Of the eight flaps, two flaps failed, but the other six flaps survived despite pedicle disruption, indicating overall survival of nine flaps after pedicle site infection. Five of the nine survived cases were healed with simple washing and ointment application. However, the other four patients, whose cause of infection was a salivary fistula, needed second flap transfer to treat those fistulas.

CONCLUSION

Disruption of anastomosed vessels can occur with high frequency after infection, causing subsequent flap loss. Therefore, surgeons need to deal with pedicle site infection to save the flap. © 2015 Wiley Periodicals, Inc. Microsurgery 36:658-663, 2016.

Microsurgery and the Hypercoagulable State: A Hematologist's Perspective

Hypercoagulability can pose a significant problem in microsurgical reconstruction. Here, the authors provide a comprehensive review of macrovascular and microvascular clotting phenomena from the unique viewpoint of two microsurgeons and a hematologist. The authors review the literature surrounding prevention of microvascular clots and provide an extensive discussion of hereditary thrombophilia. The authors also make explicit recommendations regarding the utility of thrombophilia testing and preoperative and perioperative management strategies for patients with hypercoagulability.

Effect of heparin on prevention of flap loss in microsurgical free flap transfer: a meta-analysis

The effectiveness of heparin for thromboprophylaxis during microvascular free flap transfer is uncertain. The purpose of this meta-analysis was to determine the effect of heparin on the prevention of flap loss in microsurgical free flap transfer.A search of PubMed, Cochrane databases, and Google Scholar using combinations of the search terms heparin, free flap, flap loss, free tissue transfer was conducted on March 15, 2013. Inclusion criteria were: 1) Prospective randomized trials. 2) Retrospective, non-randomized studies. 3) Patients received free tissue transfer. Flap loss rate was used to evaluate treatment efficacy. Odds ratios (ORs) with 95% confidence intervals (CI) were calculated and compared between therapies. Four studies meet the criteria for analysis and were included. Two studiescompared aspirin and heparin, and the ORs of the 2 studies were 1.688 and 2.087. The combined OR of 2.003 (95% CI 0.976–4.109, p = 0.058) did not indicate any significant difference between heparin and aspirin therapies. Two studiescompared high and low doses of dalteparin/heparin therapies, and the ORs of the 2 studies were 4.691 and 11.00. The combined OR of 7.810 (95% CI 1.859–32.808, p = 0.005) revealed a significant difference indicating that high dose dalteparin or heparin therapy is associated with a greater flap loss rate than low dose therapy. Heparin and aspirin prophylaxis are associated with similar flap loss rates after free flap transfer, and high dose dalteparin or heparin therapy is associated with a greater flap loss rate than low dose therapy.