Key Points
Question
Does continuous vasopressor use during free-tissue transfer affect the rate of reoperation in the early postoperative period?
Findings
In this cohort study of 426 patients undergoing 449 free-flap reconstructions, no clinically meaningful difference was observed in the rate of reoperation between patients receiving vasopressors (n = 174) and those who did not (n = 275).
Meaning
Continuous vasopressors were not associated with clinically significant free-flap outcomes.
This cohort study investigates the association between continuous vasopressor use and the incidence of reoperation in the early postoperative period for patients undergoing free-flap reconstruction.
Abstract
Importance
Continuous vasopressor use in free-flap reconstruction is a point of contention among microvascular surgeons despite data demonstrating safety.
Objective
To investigate the association between continuous vasopressor use and the incidence of reoperation in the early postoperative period.
Design, Setting, and Participants
In this cohort study, a retrospective medical record review was conducted of patients who underwent head and neck free-flap reconstructions between May 1, 2014, and October 31, 2019, in an academic tertiary care center. All patients undergoing free-flap reconstruction for head and neck defects were included.
Exposures
Continuous intraoperative vasopressors.
Main Outcomes and Measures
Patient medical records were queried for demographic variables; intraoperative use of vasopressors; vasopressor type, duration, and infusion rate; reoperation within the first 5 postoperative days; and reason for reoperation.
Results
Four hundred forty-nine consecutive free-flap reconstructions were performed on 426 patients. The mean age was 62 years (IQR, 55.7-71.1); 293 patients were men (65.3%), 380 were White (84.6%), 55 were Black (12.2%), and 14 were of other race or ethnicity (3.1%). A total of 174 patients received a continuous vasopressor during their reconstruction. Twenty-three reoperations occurred within 5 days postoperatively, 8 of which included vasopressors during initial intervention. Vasopressor type had no association with reoperation (4.5% vs 5.5% [8/174 vs 15/275, respectively] for patients who received vasopressors vs those who did not) (dobutamine odds ratio [OR], 1.02 [95% CI, 0.21-2.91]; dopamine OR, 1.48 [95% CI, 0.33-4.26]). No difference was seen in the duration (dobutamine OR, 1.50 [95% CI, 0.78-2.90]; dopamine OR, 0.87 [95% CI, 0.59-1.28]) or infusion rate (dobutamine OR, 1.50 [95% CI, 0.99-1.02]; dopamine OR, 1.00 [95% CI, 0.99-1.01]) of vasopressors between patients who underwent reoperation and those who did not. Analysis after the exclusion of reasons for reoperation that did not represent possible microvascular anastomosis failure (eg, Doppler malfunction, donor site complications) showed no increased propensity for reoperation (OR, 1.18; 95% CI, 0.27-3.9).
Conclusions and Relevance
In this cohort study, use of vasopressors for extensive periods intraoperatively during free-tissue transfer appeared to have no association with the rate of reoperation within 5 days of intervention, regardless of agent used, simultaneous use of agents, type of free-flap operation performed, or reason for reoperation. This study adds to the body of literature supporting the judicious use of vasopressors in patients requiring intraoperative pharmacological pressure support during free-flap reconstruction.
Introduction
Free-tissue transfer has become the standard of care for the reconstruction of most complex head and neck defects because it possesses clear advantages in reducing donor site morbidity while improving form and function, in contrast to other reconstructive modalities.1,2 However, the performance of free-tissue transfer is technically complex, requires meticulous attention to detail, and necessitates intensive postoperative monitoring. Early detection of common causes of free-flap failure—namely, venous and arterial thrombosis, arterial vasospasm, infection, and hematoma—provides increased opportunity for successful surgical salvage and, thus, avoidance of the clinical ramifications of flap failure for both the patient and surgeon.3 The ramifications almost invariably include additional surgical procedures, increased duration of hospital stay, and decreased likelihood of an optimal functional outcome.4
Maintenance of intraoperative hemodynamic stability ensures adequate tissue perfusion pressures and has been shown to play an important role in free-tissue transfer feasibility.4 Furthermore, intraoperative hypotension is associated with poor outcomes because of inadequate end-organ perfusion, and thus a mean arterial pressure goal of 80 mm Hg or greater is commonly maintained.5 Interventions to prevent intraoperative hypotension are beyond the scope of this article but are commonly used because patients with head and neck cancer often possess multiple comorbidities, and free-tissue transfer results in increased surgical times.5,6 Excessive intravascular volume expansion has been shown to have negative cardiopulmonary effects, especially for patients undergoing free-tissue transfer.4,7,8 The risk of prolonged pedicle vasospasm in response to vasopressor usage is a common concern among microsurgeons despite evidence that vasopressors may increase flap perfusion.9,10 The underpinning of this concern is both theoretical and empirical because some animal models have demonstrated decreased skin perfusion after the administration of vasopressors, most notably phenylephrine. However, a review of multiple animal models ultimately reveals conflicting results.11
Although currently available studies assessing vasopressor use in patients undergoing head and neck free-flap reconstruction report primarily on the association of vasopressor use and rate of flap failure, none to our knowledge specifically investigate the effect of vasopressor use on the need for reoperation. Therefore, we sought to add to the body of literature by closely examining this association, as well as characterizing the association of vasopressor use with reoperation according to type, number used (1 vs 2), duration, and infusion rate and dosage.
Methods
Patient Selection
A retrospective medical record review was conducted at the University of Arkansas for Medical Sciences, a single academic tertiary care center. Approval was obtained from the University of Arkansas for Medical Sciences institutional review board, as was a waiver of informed consent owing to the retrospective nature of this cohort study. The study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline. Our electronic medical record system was queried for all patients undergoing free-tissue transfer between May 1, 2014, and October 31, 2019, to establish the sample population for investigation. Data were collected on a per-flap vs per-patient basis to account for instances of multiple free-flap procedures per patient in the study period. The following data points were extracted from the patients’ electronic medical record: age, sex, race and ethnicity, American Society of Anesthesiologists score, type of flap, use of continuous vasopressor to maintain a mean arterial pressure of 80 mm Hg, type of vasopressor as well as the duration and amount and infusion rate, reoperation within the first 5 postoperative days, and reason for reoperation. No patients were excluded from the study. Patients were divided into 2 cohorts, those receiving vasopressors vs not receiving them.
Statistical Analysis
Statistical analysis was performed with SPSS Statistics Premium version 27.0 (IBM Corp). The infusion rate and duration of the various vasopressors were analyzed by analysis of variance. χ2 Analysis was used to determine whether any differences observed in patient demographic variables or outcomes based on flap type or vasopressor used were statistically significant. Pearson and Spearman correlations were performed on nominal and ordinal data, respectively. Odds ratios (ORs) and 95% CIs were calculated with a bootstrapping procedure (1000 iterations), implementing a bias-corrected and accelerated bootstrap to adjust for both bias and skewness in the bootstrap distribution. The effect of the number of vasopressors was evaluated with a Mann-Whitney U test. Binomial logistic regression was used to examine the effect of infusion rate and duration of dobutamine and dopamine on reoperation. P < .05 was used to determine statistical significance. P values were calculated with analysis of variance, χ2, and t test in 2-sided tests.
Results
A total of 426 patients underwent 449 free-flap reconstructions within the study period. The mean age of patients undergoing surgery was 62 years (IQR, 55.7-71.1); 293 patients were men (65.3%), and 156 were women (34.7%). The cohort comprised 380 White individuals (84.6%), 55 Black individuals (12.2%), and 14 of other race or ethnicity (3.1%), including Asian individuals, unknown ethnicity, and those listed as “other” in the medical record. Analysis of age between patients receiving or not receiving vasopressors showed a higher age among those who received a vasopressor (mean difference, 5.4 years; 95% CI, 2.9-7.7). However, age was not associated with reoperation (age difference, −3.24 years; 95% CI, −10.94 to 3.19). The most commonly used free flaps within the cohort were anterolateral thigh (165 of 449 [36.7%]), radial forearm (151 of 449 [33.6%]), and osteocutaneous fibular (99 of 449 [22.0%]). The site of reconstruction was heterogeneous throughout the cohort, with the majority of the flaps performed in oral cavity subsites (285 of 449 [63.5%]), followed by cutaneous defects (68 of 449 [15.1%]) (Table 1). Sex, race, American Society of Anesthesiologists score, and type of flap were not associated with use of vasopressors.
Table 1. Demographic Variables for the Population.
| Variable | No. (%) | ||
|---|---|---|---|
| Total population (n = 449) | No VP (n = 275) | VP (n = 174) | |
| Age, mean (IQR), y | 62.5 (55.7-71.1) | 60.4 (52-69) | 65.7 (58.75-72.00) |
| Sex | |||
| Men | 293 (65.3) | 176 (64.0) | 117 (67.2) |
| Women | 156 (34.7) | 99 (36.0) | 57 (32.8) |
| Race and ethnicity | |||
| Black | 55 (12.2) | 37 (13.5) | 18 (10.3) |
| White | 380 (84.6) | 230 (83.6) | 150 (86.2) |
| Othera | 14 (3.1) | 8 (2.9) | 6 (3.4) |
| ASA score | |||
| 1 | 3 (0.7) | 3 (1.1) | 0 |
| 2 | 79 (17.6) | 52 (18.9) | 27 (15.5) |
| 3 | 322 (71.7) | 195 (70.9) | 127 (73.0) |
| 4 | 28 (6.2) | 13 (4.7) | 15 (8.6) |
| Type of flap | |||
| Anterolateral thigh | 165 (36.7) | 95 (34.5) | 70 (40.2) |
| Radial forearm | 151 (33.6) | 99 (36.0) | 52 (29.9) |
| Fibula | 99 (22.0) | 62 (22.5) | 37 (21.3) |
| Other (LTD, SCPL, rectus, VL, or TFL) | 34 (7.6) | 19 (6.9) | 15 (8.6) |
| Defect site | |||
| Oral cavity | 285 (63.5) | 171 (62.2) | 114 (65.5) |
| Pharynx | 25 (5.6) | 19 (6.9) | 6 (3.4) |
| Larynx | 27 (6) | 13 (4.7) | 14 (8.0) |
| Cutaneous | 68 (15.1) | 38 (13.8) | 30 (17.2) |
| Skull base or orbit | 29 (6.5) | 22 (8.0) | 7 (4.0) |
| Other | 15 (3.3) | 12 (4.4) | 3 (1.7) |
Abbreviations: ASA, American Society of Anesthesiologists; LTD, latissimus dorsi; SCPL, scapula; TFL, tensor fascia lata; VL, vastus lateralis; VP, vasopressor.
Other includes Asian, unknown ethnicity, or listed as “other” within the medical record.
A total of 174 operations included at least 1 vasopressor to maintain a mean arterial pressure goal of 80 mm Hg. One hundred fifty-two operations included 1 vasopressor, whereas 22 included 2 vasopressors to maintain the mean arterial pressure goal. Twenty-three patients had a reoperation of some kind within the first 5 postoperative days, 8 of which included intraoperative vasopressor usage during the initial intervention. The vasopressors used were dobutamine, dopamine, norepinephrine, and phenylephrine. Analysis of the distribution of each vasopressor with respect to flap donor site indicated an even distribution with no association between donor site and reoperation (Table 2). No patients who received phenylephrine, norepinephrine, or multiple vasopressors underwent reoperation. For individual vasopressor use, reoperative patients were compared with nonreoperative ones who received the same vasopressor. No patients who received phenylephrine or norepinephrine underwent reoperation, and thus their data were not analyzed for individual effect. The type of vasopressor was not associated with reoperation (dobutamine OR, 1.02 [95% CI, 0.21-2.91]; dopamine OR, 1.48 [95% CI, 0.33-4.26]). No difference was appreciated in the duration (dobutamine OR, 1.50 [95% CI, 0.78-2.90]; dopamine OR, 0.87 [95% CI, 0.59-1.28]) or infusion rate (dobutamine OR, 1.00 [95% CI, 0.99-1.02]; dopamine OR, 1.00 [95% CI, 0.99-1.01]) between patients who underwent reoperation and those who did not (Table 3).
Table 2. Distribution of Individual Vasopressors and Reoperation With Respect to Flap Donor Site Within the Vasopressor Cohorta.
| Donor site | No. (%) | ||||
|---|---|---|---|---|---|
| Dobutamine | Dopamine | Norepinephrine | Phenylephrine | Reoperation | |
| Anterolateral thigh | 38 (54.3) | 19 (27.1) | 2 (2.9) | 11 (15.7) | 2 (2.9) |
| Radial forearm | 25 (48.1) | 14 (26.9) | 1 (1.9) | 12 (23.1) | 1 (1.9) |
| Fibula | 15 (40.5) | 15 (40.5) | 0 | 7 (18.9) | 4 (10.8) |
| Other (LTD, SCPL, rectus, VL, or TFL) | 5 (33.3) | 6 (40) | 0 | 4 (26.7) | 1 (6.7) |
Abbreviations: LTD, latissimus dorsi; SCPL, scapula; TFL, tensor fascia lata; VL, vastus lateralis.
Flap type was not found to have any association with respect to specific vasopressor use or reoperation.
Table 3. Reoperation as a Function of Duration and Infusion of Different Vasopressorsa.
| Variable | Dopamine (n = 54) | OR (95% CI) | Dobutamine (n = 83) | OR (95% CI) |
|---|---|---|---|---|
| Mean duration, h | ||||
| No reoperation | 3.9 | 0.87 (0.59-1.28) | 3.7 | 1.50 (0.78-2.90) |
| Reoperation | 4.9 | 2.5 | ||
| Mean rate of infusion, mg/h | ||||
| No reoperation | 24.9 | 1.00 (0.99-1.01) | 19.2 | 1.00 (0.99-1.02) |
Abbreviation: OR, odds ratio.
Mean duration and mean infusion rate were not associated with reoperation for either dobutamine or dopamine. The phenylephrine (n = 34) and norepinephrine (n = 3) subgroups did not have any patients who underwent reoperation and thus were excluded from this subgroup analysis.
Within our study, approximately 5% (23 of 449) of all free-flap patients received reoperation, 4.6% (8 of 174) for patients not receiving a vasopressor and 5.5% (15 of 275) for those who did. Investigation of cause for reoperation revealed that more than 25% of reoperations (6 of 23) were owing to implantable Doppler malfunction and not true impending flap failure (Table 4). Nine of 13 reoperations that could cause anastomosis failure were owing to thrombosis (arterial, 5 [38.5%]; venous, 4 [30.8%]), followed by hematoma (3 [23.1%]). Analysis of reoperation in patients receiving vasopressor vs those who did not showed no increased incidence of reoperation (OR, 0.84; 95% CI, 0.28-2.04). Further analysis after the exclusion of reasons for reoperation that did not represent possible microvascular anastomosis failure (eg, Doppler malfunction, donor site complications) still showed no increased propensity for reoperation (OR, 1.18; 95% CI, 0.27-3.91). Analysis of reasons for reoperation subcategories in which both cohorts had reoperative patients showed no increased odds for reoperation (arterial thrombus OR, 6.48 [95% CI, 0.72-58.43]; venous thrombus OR, 1.62 [95% CI, 0.23-11.60]; all thrombi OR, 3.24 [95% CI, 0.80-13.12]). No patients who received 2 vasopressors underwent reoperation within the first 5 postoperative days.
Table 4. Association of Vasopressor Use and Reason for Reoperation Within First 5 Postoperative Daysa.
| Reason for reoperation | No. | |
|---|---|---|
| No VP | VP | |
| Implantable Doppler malfunction | 6 | 0 |
| Arterial vasospasm | 1 | 0 |
| Arterial thrombus | 1 | 4 |
| Venous thrombus | 2 | 2 |
| Neck hematoma | 3 | 0 |
| Donor site hematoma | 2 | 1 |
| Other | 0 | 1 |
| OR (95% CI) for all reasons | 0.84 (0.28-2.04) | |
Abbreviations: OR, odds ratio; VP, vasopressor.
Vasopressor use did not increase odds of reoperation by overall reason.
Discussion
Multiple studies have reported on intraoperative use of vasopressor and definitive free-flap outcomes, largely demonstrating a lack of association. To more closely study the outcomes associated with vasopressor use in this setting, this study’s primary objective was to determine whether there was an increased risk of reoperation in patients who received continuous intraoperative vasopressor usage to maintain a mean arterial pressure goal of 80 mm Hg or greater. The intraoperative component of our institutional clinical pathway for free flaps seeks to optimize mean arterial pressure by exercising judicious use of intravascular fluids and use of vasopressor support, when necessary, to avoid volume overload.12 Within our study population, various vasopressors were used, occasionally simultaneously, for patients undergoing a variety of free-tissue reconstructions. On analysis of vasopressor type used and type of flap performed, none demonstrated an association with reoperation.
The timing of vasopressor administration, whether during induction of anesthesia or intraoperatively, is not associated with flap necrosis,13 even within 2 hours of the performance of microvascular anastomosis.4 Despite these investigations, the association of the mean duration and infusion rate and dosage of vasopressors with flap outcomes is not well described in the literature. Although this study did not directly measure the temporal association of vasopressor usage on microvascular anastomosis, the average duration of vasopressor use indicated that vasopressors were not used solely for the treatment of postinduction hypotension. The majority of vasopressors were used as an infusion during several hours, constituting a large portion of the operation time, and therefore likely in close temporal proximity to the microvascular component of the procedure. The lack of an association of vasopressor duration and infusion rate and dosage with the incidence of reoperation suggests the safety of these medications’ use when necessary and thus serves as an important contribution to the existing body of literature.
Investigation of the cause for reoperation demonstrated that a large portion of patients who received reoperation were not at risk of flap loss and were experiencing technical failure of the flap-monitoring device or donor site complications. Despite a lack of association with these patients included, when these reasons for reoperation were excluded in a subset analysis of only patients at risk for microvascular anastomosis failure, there was no association between vasopressor use and reoperation owing to any specific cause (Table 4). Most important, our findings indicate that there is no increase in risk between vasopressor use and reoperation. Furthermore, in the small subset of patients who received 2 vasopressors to maintain the mean arterial pressure goal, no patients underwent reoperation in the early postoperative period. Our findings are in alignment with previously reported data, illustrating that not only are vasopressors not implicated in flap failure but also they are not associated with reoperation for salvage of failing free flaps.
Microvascular reconstructive surgery of the head and neck is a great benefit to patients with composite defects, but flap loss remains a catastrophic complication that necessitates risk mitigation. The association between intraoperative hypotension and free-flap failure demonstrates that optimization of tissue perfusion is important for flap survival.7 Investigations into how this is best achieved have produced interesting results. Arterial pressure and blood viscosity are the main drivers of tissue perfusion. Animal models have shown that normovolemic hemodilution increases skin-flap perfusion.14 However, aggressive intravascular volume expansion intraoperatively has been shown to increase complication rates and length of stay.7,15,16 This volume expansion is likely multifactorial because of the multiorgan effect of volume overload; it also may lead to edema-induced mechanical stress on the pedicle and suture lines.15 Underresuscitation is known to negatively affect flap viability as well.15 Vasopressors represent a readily available method to pharmacologically increase arterial blood pressure. The theoretical risk of vasopressor usage impeding flap perfusion has dissuaded many microvascular surgeons from use in patients,9 despite no validation within the literature of this risk in humans.11
Limitations
A substantial limitation of this study is the small number of patients who received multiple vasopressors and who underwent reoperation after vasopressor use. At the current rate of reoperation for each group, a properly powered study would necessitate a sample size of 14 910 procedures, which would be exceedingly difficult to achieve. As such, we believe that the findings of this single-institution cohort study add valuable information to the body of evidence on the subject. Although the relatively small sample size undermined our ability to make definitive conclusions, our assertion that there is no clinical association between vasopressor usage and perioperative outcomes is supported by the magnitude of the effect size and the inclusion of clinically meaningful differences within the CI range.
An additional limitation that is inherent to virtually all cohort studies is the presence of multiple confounding variables. Fang et al17 pointed out that in the context of microvascular procedures, vasopressors are used in a restricted capacity determined by clinical judgment, and our study population was no different in this regard. Factors such as radiation exposure and nitrate or bronchodilator use may also play a role in flap complications.16 Prolonged operative times have been proven to negatively influence flap survival,18,19,20 likely because of prolonged ischemia and reperfusion injury,21 and can be affected by use of alternate recipient vessels that require extensive dissection for access.22 Although we have attempted to account for some of these variables, such as flap type, in our analysis, the retrospective nature and heterogenous population are inherent limitations. This study further highlights the lack of evidence linking free-flap failure with the use of intraoperative vasopressors. It adds to previous studies by specifically investigating the effects of vasopressor use on the incidence of reoperation, which to our knowledge has not been previously reported. This analysis also specifically assessed each vasopressor used and simultaneous use of vasopressors, in addition to duration and infusion rate and dosage of each vasopressor used.
Conclusions
In this cohort study, use of vasopressors for extensive periods intraoperatively during free-tissue transfer appeared to have no association with the rate of reoperation within 5 days of intervention, regardless of agent used, simultaneous use of agents, type of free flap used, or reason for reoperation. This study adds to the body of literature supporting the judicious use of vasopressors in free-flap patients receiving intraoperative pharmacological pressure support.
References
- 1.Pou AM, Johnson JT. Oropharyngeal cancer. In: Johnson JT, Rosen CA, eds. Bailey’s Head and Neck Surgery—Otolaryngology. 5th ed. Lippincott Williams & Wilkins; 2014:1898-1916. [Google Scholar]
- 2.Chepeha DB. Reconstructive microsurgery of the head and neck. In: Johnson JT, Rosen CA, eds. Bailey’s Head and Neck Surgery—Otolaryngology. 5th ed. Lippincott Williams & Wilkins; 2014:2824-2848. [Google Scholar]
- 3.Zhou W, Zhang WB, Yu Y, et al. Risk factors for free flap failure: a retrospective analysis of 881 free flaps for head and neck defect reconstruction. Int J Oral Maxillofac Surg. 2017;46(8):941-945. doi: 10.1016/j.ijom.2017.03.023 [DOI] [PubMed] [Google Scholar]
- 4.Wax MK, Azzi J. Perioperative considerations in free flap surgery: a review of pressors and anticoagulation. Oral Oncol. 2018;83:154-157. doi: 10.1016/j.oraloncology.2018.06.025 [DOI] [PubMed] [Google Scholar]
- 5.Südfeld S, Brechnitz S, Wagner JY, et al. Post-induction hypotension and early intraoperative hypotension associated with general anaesthesia. Br J Anaesth. 2017;119(1):57-64. doi: 10.1093/bja/aex127 [DOI] [PubMed] [Google Scholar]
- 6.Cannesson M, de Backer D, Hofer CK. Using arterial pressure waveform analysis for the assessment of fluid responsiveness. Expert Rev Med Devices. 2011;8(5):635-646. doi: 10.1586/erd.11.30 [DOI] [PubMed] [Google Scholar]
- 7.Kass JL, Lakha S, Levin MA, et al. Intraoperative hypotension and flap loss in free tissue transfer surgery of the head and neck. Head Neck. 2018;40(11):2334-2339. doi: 10.1002/hed.25190 [DOI] [PubMed] [Google Scholar]
- 8.Vincent A, Sawhney R, Ducic Y. Perioperative care of free flap patients. Semin Plast Surg. 2019;33(1):5-12. doi: 10.1055/s-0038-1676824 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Vyas K, Wong L. Intraoperative management of free flaps: current practice. Ann Plast Surg. 2014;72(6):S220-S223. doi: 10.1097/SAP.0000000000000096 [DOI] [PubMed] [Google Scholar]
- 10.Eley KA, Young JD, Watt-Smith SR. Epinephrine, norepinephrine, dobutamine, and dopexamine effects on free flap skin blood flow. Plast Reconstr Surg. 2012;130(3):564-570. doi: 10.1097/PRS.0b013e31825dbf73 [DOI] [PubMed] [Google Scholar]
- 11.Monroe MM, McClelland J, Swide C, Wax MK. Vasopressor use in free tissue transfer surgery. Otolaryngol Head Neck Surg. 2010;142(2):169-173. doi: 10.1016/j.otohns.2009.11.001 [DOI] [PubMed] [Google Scholar]
- 12.Moreno MA, Bonilla-Velez J. Clinical pathway for abbreviated postoperative hospital stay in free tissue transfer to the head and neck: impact in resource utilization and surgical outcomes. Head Neck. 2019;41(4):982-992. doi: 10.1002/hed.25525 [DOI] [PubMed] [Google Scholar]
- 13.Kelly DA, Reynolds M, Crantford C, Pestana IA. Impact of intraoperative vasopressor use in free tissue transfer for head, neck, and extremity reconstruction. Ann Plast Surg. 2014;72(6):S135-S138. doi: 10.1097/SAP.0000000000000076 [DOI] [PubMed] [Google Scholar]
- 14.Johnson JT, Rosen, CA. Critical care. In: Johnson JT, Rosen CA, eds. Bailey’s Head and Neck Surgery—Otolaryngology. 5th ed. Lippincott Williams & Wilkins; 2014:57. [Google Scholar]
- 15.Dort JC, Farwell DG, Findlay M, et al. Optimal perioperative care in major head and neck cancer surgery with free flap reconstruction: a consensus review and recommendations from the Enhanced Recovery After Surgery Society. JAMA Otolaryngol Head Neck Surg. 2017;143(3):292-303. doi: 10.1001/jamaoto.2016.2981 [DOI] [PubMed] [Google Scholar]
- 16.Lahtinen SL, Liisanantti JH, Poukkanen MM, Laurila PA. Goal-directed fluid management in free flap surgery for cancer of the head and neck. Minerva Anestesiol. 2017;83(1):59-68. doi: 10.23736/S0375-9393.16.11451-8 [DOI] [PubMed] [Google Scholar]
- 17.Fang L, Liu J, Yu C, Hanasono MM, Zheng G, Yu P. Intraoperative use of vasopressors does not increase the risk of free flap compromise and failure in cancer patients. Ann Surg. 2018;268(2):379-384. doi: 10.1097/SLA.0000000000002295 [DOI] [PubMed] [Google Scholar]
- 18.Sanati-Mehrizy P, Massenburg BB, Rozehnal JM, Ingargiola MJ, Hernandez Rosa J, Taub PJ. Risk factors leading to free flap failure: analysis from the National Surgical Quality Improvement Program Database. J Craniofac Surg. 2016;27(8):1956-1964. doi: 10.1097/SCS.0000000000003026 [DOI] [PubMed] [Google Scholar]
- 19.Ishimaru M, Ono S, Suzuki S, Matsui H, Fushimi K, Yasunaga H. Risk factors for free flap failure in 2,846 patients with head and neck cancer: a national database study in Japan. J Oral Maxillofac Surg. 2016;74(6):1265-1270. doi: 10.1016/j.joms.2016.01.009 [DOI] [PubMed] [Google Scholar]
- 20.Serletti JM, Higgins JP, Moran S, Orlando GS. Factors affecting outcome in free-tissue transfer in the elderly. Plast Reconstr Surg. 2000;106(1):66-70. doi: 10.1097/00006534-200007000-00012 [DOI] [PubMed] [Google Scholar]
- 21.Pattani KM, Byrne P, Boahene K, Richmon J. What makes a good flap go bad? a critical analysis of the literature of intraoperative factors related to free flap failure. Laryngoscope. 2010;120(4):717-723. doi: 10.1002/lary.20825 [DOI] [PubMed] [Google Scholar]
- 22.Lin Y, He JF, Zhang X, Wang HM. Intraoperative factors associated with free flap failure in the head and neck region: a four-year retrospective study of 216 patients and review of the literature. Int J Oral Maxillofac Surg. 2019;48(4):447-451. doi: 10.1016/j.ijom.2018.08.009 [DOI] [PubMed] [Google Scholar]
