Effect of Overlapping Operations on Outcomes in Microvascular Reconstructions of the Head and Neck

Overlapping Surgery in Orthopaedics: A Review of Efficacy, Surgical Costs, Surgical Outcomes, and Patient Safety

INTRODUCTION

Overlapping surgery (OS) refers to when an attending surgeon supervises two surgeries at the same time with noncritical portions of both surgeries occurring simultaneously. Limited literature reviewing OS exists in orthopaedics. Our goal is to provide insight into this practice across orthopaedic subspecialities to inform its future utilization.

METHODS

A review of the literature was conducted after Preferred Reporting Items for Systematic Reviews and Meta-Analyses systematic review guidelines. All articles (630 total) were independently reviewed by two authors with a third to resolve discrepancies. Inclusion criteria encompassed any journal publication that included data on a series of orthopaedic OS. Data points sought included the type of surgery, quantity of cases, case duration, overlap time, perioperative complications, and cost.

RESULTS

Eleven articles met the inclusion criteria, encompassing a total of 34,494 overlapping surgeries. The studies varied regarding setting and subspecialties included. Six studies demonstrated increased surgical times for overlap cases. Two studies found that although OS increased cost per case, it improved the overall efficiency. Ten studies tracked short-term outcomes (<90 days) and reported no increase in complications with OS. Only one study examined long-term outcomes (1 year) and found a markedly increased risk for surgical complications with OS, with higher complication rates among nonelective compared with elective cases.

DISCUSSION

Current literature suggests that OS may increase surgical time, but from the 11 articles reviewed, only one demonstrates an increase in perioperative complications across orthopaedic subspecialities. OS also seems to increase costs per case; however, this is offset by the ability to perform more cases in the same period, resulting in an overall increase in the net profit. These data are consistent with studies from other surgical specialties.

CONCLUSION

Although OS seems to be both safe and effective, future investigations are needed to understand the impact it has on patients and healthcare systems.

Microvascular Reconstruction of Osteonecrosis: Assessment of Long-term Quality of Life

OBJECTIVE

Review long-term clinical and quality-of-life outcomes following free flap reconstruction for osteonecrosis.

STUDY DESIGN

Retrospective multi-institutional review.

SETTING

Tertiary care centers.

METHODS

Patients included those undergoing free flap reconstructions for osteonecrosis of the head and neck (N = 232). Data included demographics, defect, donor site, radiation history, perioperative management, diet status, recurrence rates, and long-term quality-of-life outcomes. Quality-of-life outcomes were measured using the University of Washington Quality of Life (UW-QOL) survey.

RESULTS

Overall flap success rate was 91% (n = 212). Relative to preoperative diet, 15% reported improved diet function at 3 months following reconstruction and 26% at 5 years. Osteonecrosis recurred in 14% of patients (32/232); median time to onset was 11 months. Cancer recurrence occurred in 13% of patients (29/232); median time to onset was 34 months. Results from the UW-QOL questionnaire were as follows: no pain (45%), minor or no change in appearance (69%), return to baseline endurance level (37%), no limitations in recreation (40%), no changes in swallowing following reconstruction (28%), minor or no limitations in mastication (29%), minor or no speech difficulties (93%), no changes in shoulder function (84%), normal taste function (19%), normal saliva production (27%), generally excellent mood (44%), and no or minimal anxiety about cancer (94%).

CONCLUSION

The majority of patients maintained or had advancement in diet following reconstruction, with low rates of osteonecrosis or cancer recurrence and above-average scores on UW-QOL survey suggesting good return of function and quality of life.

Perceptions and Awareness of Overlapping Surgery in Patients With Shoulder Pain Presenting to an Orthopaedic Sports Medicine Clinic

Purpose

To determine patients’ baseline understanding of overlapping surgery and to evaluate how education changes the perception of the practice in orthopaedic shoulder pain patients at a single institution.

Methods

All patients who visit the clinic with a chief complaint of shoulder pain were given a 15-question survey. The initial 15-question survey assessed demographics, pre-existing knowledge on the practice of overlapping surgery, and their perception of it. They immediately read a statement on the practice of overlapping surgery. After reading the statement, patients were re-evaluated on their level of concern.

Results

A total of 100 patients (55 female, 45 male) completed the survey. Mean age was 53.0 (range, 18-85) years. In total, 38 (38%) had no knowledge on the practice of overlapping surgery; 27 (27%) reported their level of concern as a 1, the lowest level of concern. Overall, 84 (84%) patients reported a level of concern of 3 (median) or lower, indicating a low level of concern. A total of 95 (95%) patients reported either a decrease or no change in level of concern after reading an educational statement on overlapping surgery practices, and 60 (60%) believed there would be no impact if an overlapping surgery was performed. If a patient reported a high level of concern, the most common reasons cited were that the attending physician may not be available during the whole case (15%); that a resident, fellow, or physician assistant may jeopardize the patient’s care (24%); or that a critical step would be missed (37%).

Conclusions

There is a low level of baseline understanding of overlapping surgery in patients with shoulder pain. An educational component added during patient counseling proved to be effective in decreasing the level of concern. This study suggests that counseling and education on overlapping surgery may change patient perception and opinion of the practice.

Clinical Relevance

Serves as an evaluation of the knowledge of a specific patient population on overlapping surgery and how it changes with counseling and education.

Factors impacting successful salvage of the failing free flap

BACKGROUND

Understanding factors impacting successful salvage of a compromised free flap.

METHODS

Multi-institutional review of free flap reconstructions for head and neck defects (n = 1764).

RESULTS

Free flap compromise rate: 9% (n = 162); 46% salvaged (n = 74). Higher salvage rates in initial 48 hours (64%) vs after (30%; P < .001). Greater compromise (14%) and failure (8%) if inset challenging vs straightforward (6% compromise, 4% failure; P = .035). Greater compromise (23%) and failure (17%) following intraoperative anastomosis revision vs no revision (7% compromise, 4% failure; P < .0001). Success following arterial insufficiency was lower (60% failed, 40% salvaged) vs venous congestion (23% failed, 77% salvaged) (P < .0001). Greater flap salvage following thrombectomy (66%) vs no thrombectomy (34%; P < .0001). Greater flap salvage if operative duration ≤8 hours (57%), vs >8 hours (40%) (P = .04).

CONCLUSIONS

There were higher rates of free flap salvage if the vascular compromise occurred within 48 hours, if due to venous congestion, if operative duration ≤8 hours, and if the anastomosis did not require intraoperative revision.

Overlapping Surgery Increases Operating Room Efficiency Without Adversely Affecting Outcomes in Total Hip and Knee Arthroplasty

BACKGROUND

Several recent studies have demonstrated that overlapping surgeries in total hip (THA) and knee (TKA) arthroplasty do not increase the rates of complications, but whether this practice is cost-effective has yet to be addressed in the literature. The purpose of this study is to determine the effect of overlapping surgery on procedural costs and surgical productivity during THA and TKA.

METHODS

We identified all patients undergoing primary THA or TKA from 2015 to 2018 by 18 surgeons at a single orthopedic specialty hospital. Procedural and personnel costs were calculated for each case using a time-driven activity-based costing algorithm. Overlap of surgical time by at least 30 minutes was used to define an overlapping procedure. We compared costs and outcomes between overlapping and nonoverlapping procedures, standardizing all costs to 8-hour time blocks. A multivariate regression analysis was performed to determine independent effect of overlapping procedures on costs and outcomes.

RESULTS

Of the 4786 consecutive procedures, 968 (20.2%) overlapped by at least 30 minutes. Although overlapping rooms increased mean operative time by 8.3 minutes (P < .0001) and operating room personnel costs by $80 per case (<.0001), overlapping surgeons could perform significantly more procedures per 8 hours (7.6 vs 6.4; P < .0001), increasing total 8-hour profit margin by $1215 per procedure. There was no difference in 90-day readmission rate, length of stay, or rates of discharge home between the groups.

CONCLUSION

Overlapping noncritical portions of procedures in primary THA and TKA appear to be both a safe practice and an effective strategy.

Assessment of Short-Term Patient Outcomes Following Overlapping Orthopaedic Surgery at a Large Academic Medical Center

BACKGROUND

Overlapping surgery is a long-standing practice that has not been well studied. The aim of this study was to assess whether overlapping surgery is associated with untoward outcomes for orthopaedic patients.

METHODS

Coarsened exact matching was used to assess the impact of overlap on outcomes among elective orthopaedic surgical interventions (n = 18,316) over 2 years (2014 and 2015) at 1 health-care system. Overlap was categorized as any overlap, and subcategories of exclusively beginning overlap and exclusively end overlap. Study subjects were matched on the Charlson comorbidity index score, duration of surgery, surgical costs, body mass index, length of stay, payer, and race, among others. Serious unanticipated events were studied.

RESULTS

A total of 3,395 patients had any overlap and were matched (a match rate of 90.8% of 3,738). For beginning and end overlap, matched groups were created, with a match rate of 95.2% of 1043 and 94.7% of 863, respectively. Among matched patients, any overlap did not predict an unanticipated return to surgery at 30 days (8.2% for any overlap and 8.3% for no overlap; p = 0.922) or 90 days (14.1% and 14.1%, respectively; p = 1.000). Patients who had surgery with any overlap demonstrated no difference compared with controls with respect to reoperation, readmission, or emergency room (ER) visits at 30 or 90 days (a reoperation rate of 3.1% and 3.2%, respectively [p = 0.884] at 30 days and 4.2% and 3.5% [p = 0.173] at 90 days; a readmission rate of 10.3% and 11.0% [p = 0.352] at 30 days and 5.5% and 5.2% [p = 0.570] at 90 days; and an ER visit rate of 5.2% and 4.6% [p = 0.276] at 30 days and 4.8% and 4.3% [p = 0.304] at 90 days). Patients with surgical overlap showed reduced mortality compared with controls during follow-up (1.8% and 2.6%, respectively; p = 0.029). Patients with beginning and/or end overlap had a similar lack of association with serious unanticipated events; however, patients with end overlap showed an increased unexpected rate of return to the operating room after reoperation at 90 days (13.3% versus 9.7%; p = 0.015).

CONCLUSIONS

Nonconcurrent overlapping surgery was not associated with adverse outcomes in a large, matched orthopaedic surgery population across 1 academic health system.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Association of overlapping cardiac surgery with short-term patient outcomes

OBJECTIVE

This study seeks to assess the safety of overlap in cardiac surgery.

METHODS

Coarsened exact matching was used to assess the impact of overlap on outcomes among cardiac surgical interventions (n = 4463) over 2 years (2014-2016). Overlap was categorized as any, beginning, or end overlap. Study subjects were matched 1:1 on 11 variables, including Charlson comorbidity score, surgical costs, body mass index, length of postoperative hospitalization, and race, among others. Serious unanticipated events were studied, including readmission, unplanned return to the operating room, and mortality.

RESULTS

A total of 984 patients had any overlap and were matched to similar patients without overlap (n = 1501). For beginning/end overlap, separate matched groups were created (n = 462, n = 329 patients, respectively). Among matched patients, any overlap did not predict unanticipated return to surgery at 30 or 90 days. Any overlap did not predict increased readmission, reoperation, or emergency department visits at 30 or 90 days. Overlap did not predict higher rates of death over follow-up. Beginning/end overlap had results similar to any overlap.

CONCLUSIONS

Nonconcurrent, overlapping surgery is not associated with an increase in adverse outcomes in a large, matched cardiac surgery population.

Outcomes of Overlapping Surgery in Otolaryngology

Objective

To compare outcomes in otolaryngology between overlapping and nonoverlapping surgeries.

Study Design

Retrospective cohort study.

Setting

Tertiary referral center.

Subjects and Methods

All patients undergoing otolaryngologic procedures at Stanford University Hospital between January 2009 and June 2016 were included (n = 13,479). Cases were divided into 2 cohorts: overlapping (n = 1806, 13.4%) vs nonoverlapping (n = 11,673, 86.6%). Variables reviewed were type of operation performed, multidisciplinary team involvement, complications, reoperations, readmissions, and deaths.

Results

The total complication rate over 7.5 years studied was 3.3% (n = 450). Complication rates were lower for overlapping cases (0.77%) compared to nonoverlapping cases (3.73%) with an odds ratio of 0.2014, which was statistically significant ( P < .0001). When examined by subspecialty, the complication rate for rhinology and endoscopic skull base procedures was approximately 10 times lower when overlapping (0.30%) was compared to nonoverlapping (3.15%), with an odds ratio of 0.094 ( P = .0001). There was no difference in complication rates for other surgical subspecialties. There were no deaths associated with overlapping surgery. The rate of major complications requiring reoperation was similarly lower for overlapping procedures (0.276%) compared to nonoverlapping procedures (1.35%) with an odds ratio of 0.2023 ( P = .0004). Readmission rates were lower for overlapping cases (0.49%) when compared to nonoverlapping cases (1.09%), with an odds ratio of 0.4553 ( P = .0229).

Conclusions

Patients undergoing overlapping surgery had lower overall complication rates, lower reoperation rates, lower readmission rates, and no mortalities. The institutional experience presented provides evidence that with appropriate patient and case selection, otolaryngologists may safely perform overlapping surgery without increased risk of adverse patient outcomes.

Association of a Lean Surgical Plan of the Day With Reduced Operating Room Time for Head and Neck Free Flap Reconstruction

Importance

Inefficiency in the operating room (OR) is detrimental to the patient, the hospital, and the surgeon. Head and neck procedures requiring microvascular reconstruction are complex, lengthy operations in which prolonged operative time is associated with higher complication rates and increased costs.

Objective

To use Lean methodology to identify potential OR efficiency improvement opportunities for head and neck surgical cases involving free tissue transfer, to implement an intervention, the free flap plan of the day, and to evaluate OR times after implementation.

Design, Setting, and Participants

Phase 1: In 2015, with the assistance of the Lean Promotion Office at our institution, a tertiary academic medical center, we identified efficiency-improvement opportunities for 10 patients undergoing free flap reconstruction. Phase 2: A single intervention, the free flap plan of the day, was implemented on February 1, 2016. A retrospective medical record review of head and neck free flap reconstructions beginning 2 years before the implementation of the intervention and ending 2 years after the intervention was performed from February 1, 2014 until February 1, 2018 to analyze OR times, cost, and complications. Mean OR times were compared using the t test.

Main Outcomes and Measures

In-room-to-incision time and total OR time.

Results

Phase 1: The surgical procedures of 10 patients undergoing free flap reconstruction were observed by Lean specialists, and a time study with a process map was completed. Using this framework, major opportunities for decreasing intraoperative time waste were identified. Multiple communication breakdowns were seen to drive intraoperative time waste; therefore, a free flap plan of the day was created to improve communication between team members. Phase 2: 200 patients were included in the study and were categorized into 2 groups, no plan group (n = 104) and plan group (n = 96), based on whether the plan of the day was used or not. The age and sex distributions of the study participants were not collected. Mean in-room-to-incision time was 54.3 minutes for the no plan group and 47.2 minutes for the plan group (difference, 7.1 minutes; 95% CI, 3.8-10.4 minutes). Mean total OR time was 524.1 minutes for the no plan group and 467.4 minutes for the plan group (difference, 56.7 minutes; 95% CI, 23.6-89.6 minutes).

Conclusions and Relevance

Lean methodology was used to identify efficiency-improvement opportunities for head and neck free flap reconstruction procedures and to design a focused intervention. A free flap plan of the day was used in this study to improve communication between the OR team and was found to improve efficiency and be associated with reduced OR times.

What Does it Mean for a Surgeon to “Run Two Rooms”? A Comprehensive Literature Review of Overlapping and Concurrent Surgery Policies

The aim of this study was to review and analyze all of the “concurrent surgery” (CS) and “overlapping surgery” (OS) literature with the goal of: standardizing terminology, defining discrepancies in the literature and proposing solutions for the current challenges of regulating surgery to achieve maximal safety and efficiency. The CS and OS literature has grown exponentially over the past two years. Before this, there were no significant publications addressing this topic. There is an extremely wide variance on how “running two rooms” is defined and whether it should be permitted. These differences affect our patients’ perception of this practice. The literature lacks any comprehensive review of the topic and terminology. We performed a PubMed search to identify studies that considered the issue of OS. The terms “overlapping surgery”, “concurrent surgery”, and “simultaneous surgery” (SS) were used in the query. We then analyzed the publications identified. The literature contained 18 published studies analyzing OS safety between November 2016 and June 2018. Eight were neurosurgical studies, three were orthopedic, and the remaining seven articles were in other surgical specialties. A total of 1,207,155 surgical cases (range 250–>500,000 patients) were analyzed among the 18 studies. There were 57,880 (5.04%) OS cases. The OS rates in the individual studies ranged from 1.2 to 68 per cent (Table 1). Neurosurgical studies had the highest average OS rate of 54 per cent (range 37–68%), whereas the average OS rate in orthopedic surgery was 43 per cent (range 2.7–68%). Approximately one-third of the studies were multicenter investigations (27.7%). The studies measured more than 20 distinct outcomes, but there were only five outcomes that were included in the majority of the studies: mortality rates, reoperation rates, procedure length of time, readmission rates, and hospital length of stay. The current body of literature repeatedly demonstrates that OS is a safe and effective option when undertaken by experienced surgeons who practice it frequently. For successful OS, the Mandatory Attending Portion for two surgeries must not overlap and Unnecessary Anesthesia Time must be prohibited. Hospitals and surgical specialty organizations must implement policies to assure the safe practice of OS.

Association of Overlapping Surgery With Perioperative Outcomes

IMPORTANCE

Overlapping surgery, in which more than 1 procedure performed by the same primary surgeon is scheduled so the start time of one procedure overlaps with the end time of another, is of concern because of potential adverse outcomes.

OBJECTIVE

To determine the association between overlapping surgery and mortality, complications, and length of surgery.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of 66 430 operations in patients aged 18 to 90 years undergoing total knee or hip arthroplasty; spine surgery; coronary artery bypass graft (CABG) surgery; and craniotomy at 8 centers between January 1, 2010, and May 31, 2018. Patients were followed up until discharge.

EXPOSURES

Overlapping surgery (≥2 operations performed by the same surgeon in which ≥1 hour of 1 case, or the entire case for those <1 hour, occurs when another procedure is being performed).

MAIN OUTCOMES AND MEASURES

Primary outcomes were in-hospital mortality or complications (major: thromboembolic event, pneumonia, sepsis, stroke, or myocardial infarction; minor: urinary tract or surgical site infection) and surgery duration.

RESULTS

The final sample consisted of 66 430 operations (mean patient age, 59 [SD, 15] years; 31 915 women [48%]), of which 8224 (12%) were overlapping. After adjusting for confounders, overlapping surgery was not associated with a significant difference in in-hospital mortality (1.9% overlapping vs 1.6% nonoverlapping; difference, 0.3% [95% CI, -0.2% to 0.7%]; P = .21) or risk of complications (12.8% overlapping vs 11.8% nonoverlapping; difference, 0.9% [95% CI, -0.1% to 1.9%]; P = .08). Overlapping surgery was associated with increased surgery length (204 vs 173 minutes; difference, 30 minutes [95% CI, 24 to 37 minutes]; P < .001). Overlapping surgery was significantly associated with increased mortality and increased complications among patients having a high preoperative predicted risk for mortality and complications, compared with low-risk patients (mortality: 5.8% vs 4.7%; difference, 1.2% [95% CI, 0.1% to 2.2%]; P = .03; complications: 29.2% vs 27.0%; difference, 2.3% [95% CI, 0.3% to 4.3%]; P = .03).

CONCLUSIONS AND RELEVANCE

Among adults undergoing common operations, overlapping surgery was not significantly associated with differences in in-hospital mortality or postoperative complication rates but was significantly associated with increased surgery length. Further research is needed to understand the association of overlapping surgery with these outcomes among specific patient subgroups.

Complications Following Overlapping Orthopaedic Procedures at an Ambulatory Surgery Center

BACKGROUND

Overlapping surgery occurs when a single surgeon is the primary surgeon for >1 patient in separate operating rooms simultaneously. The surgeon is present for the critical portions of each patient's operation although not present for the entirety of the case. While overlapping surgery has been widely utilized across surgical subspecialties, few large studies have compared the safety of overlapping and nonoverlapping surgery.

METHODS

In this retrospective cohort study, we reviewed the charts of patients who had undergone orthopaedic surgery at our ambulatory surgery center during the period of April 2009 and October 2015. A database of operations, including patient and surgical characteristics, was compiled. Complications had been identified and logged into the database by surgeons monthly over the study period. These monthly reports and case logs were reviewed retrospectively to identify complications. Propensity-score weighting and logistic regression models were used to determine the association between outcomes and overlapping surgery.

RESULTS

A total of 22,220 operations were included. Of these, 5,198 (23%) were overlapping, and 17,022 (77%) were nonoverlapping. The median duration of surgery overlap was 8 minutes (quartile 1 to quartile 3, 3 to 16 minutes); no operations were concurrent. After weighting, the only continuous variables that differed significantly between the groups were operative time (median, 57 compared with 56 minutes for the overlapping and the nonoverlapping group, respectively; p = 0.022), anesthesia time (median, 97 compared with 93 minutes; p < 0.001), and total tourniquet time (median, 26 compared with 22 minutes; p = 0.0093). Multivariable logistic regression models did not demonstrate an association between overlapping surgery and surgical site infection, noninfection surgical complications, hospitalization, or morbidity.

CONCLUSIONS

These data suggest that there is no association between briefly overlapping surgery and surgical site infection, noninfection surgical complications, hospitalization, and morbidity. When practiced in the manner described herein, overlapping orthopaedic surgery can be a safe practice in the ambulatory setting.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Incorporating a continuous suction system as a preventive measure against fistula-related complications in head and neck reconstructive surgery

Background

Although previous studies have focused on determining prognostic and causative variables associated with fistula-related complications after head and neck reconstructive surgery, only a few studies have addressed preventive measures. Noting that pooled saliva complicates wound healing and precipitates fistula-related complications, we devised a continuous suction system to remove saliva during early postoperative recovery.

Methods

A continuous suction system was implemented in 20 patients after head and neck reconstructive surgery between January 2012 and October 2017. This group was compared to a control group of 16 patients at the same institution. The system was placed orally when the lesion was on the anterior side of the retromolar trigone area, and when glossectomy or resection of the mouth floor was performed. When the orohypopharynx and/or larynx were eradicated, the irrigation system was placed in the pharyngeal area.

Results

The mean follow-up period was 9.2±2.4 months. The Hemovac system was applied for an average of 7.5 days. On average, 6.5 days were needed for the net drain output to fall below 10 mL. Complications were analyzed according to their causes and rates. A fistula occurred in two cases in the suction group. Compared to the control group, a significant difference was noted in the surgical site infection rate (P<0.031).

Conclusions

Clinical observations showed reduced saliva pooling and a reduction in the infection rate. This resulted in improved wound healing through the application of a continuous suction system.

Overlapping Surgery: A Case Study in Operating Room Throughput and Efficiency

A keystone of operating room (OR) management is proper OR allocation to optimize access, safety, efficiency, and throughput. Access is important to surgeons, and overlapping surgery may increase patient access to surgeons with specialized skill sets and facilitate the training of medical students, residents, and fellows. Overlapping surgery is commonly performed in academic medical centers, although recent public scrutiny has raised debate about its safety, necessitating monitoring. This article introduces a system to monitor overlapping surgery, providing a surgeon-specific Key Performance Indicator, and discusses overlapping surgery as an approach toward OR management goals of efficiency and throughput.

Characteristics and Management of Free Flap Compromise Following Internal Jugular Venous Thrombosis

PURPOSE

Free flap compromise after internal jugular venous thrombosis (IJVT) occurs fairly infrequently in oral and maxillofacial rehabilitation and reconstruction but could seriously affect the patient's postoperative recovery. The aim of this study was to analyze and discuss the characteristics and management of such flap compromise.

PATIENTS AND METHODS

The authors performed a retrospective case series of 13 patients who underwent reconstruction of oral and maxillofacial defects with anterolateral thigh flaps and developed flap compromise from IJVT from July 2014 through December 2016 at the Second Xiangya Hospital of Central South University (Changsha, China). The clinical features of flap compromise are described, and the precautions and improvement measures are reported.

RESULTS

All 13 patients were men with an average age of 50.3 years. Flap compromise caused by IJVT occurred on postoperative days 3 to 7, of which 2 flaps were salvaged (15.4%) and 11 flaps failed completely after immediate urgent re-exploration. Four patients presented with orocutaneous fistula after salvage surgery that healed well after a period of wound dressing.

CONCLUSIONS

Because of the late occurrence and low salvage rate of flap compromise caused by IJVT, intensive flap monitoring after reconstruction surgery is necessary for patients with free flap transfer.