Abstract
Introduction We evaluated the demographics, flap types, and 30-day complication, readmission, and reoperation rates for upper extremity free flap transfers within the National Surgical Quality Improvement Program (NSQIP) database.
Materials and Methods Upper extremity free flap transfer patients in the NSQIP from 2008 to 2016 were identified. Complications, reoperations, and readmissions were queried. Chi-squared tests evaluated differences in sex, race, and insurance. The types of procedures performed, complication frequencies, reoperation rates, and readmission rates were analyzed.
Results One-hundred-eleven patients were selected (mean: 36.8 years). Most common upper extremity free flaps were muscle/myocutaneous (45.9%) and other vascularized bone grafts with microanastomosis (27.9%). Thirty-day complications among all patients included superficial site infections (2.7%), intraoperative transfusions (7.2%), pneumonia (0.9%), and deep venous thrombosis (0.9%). Thirty-day reoperation and readmission rates were 4.5% and 3.6%, respectively. The mean time from discharge to readmission was 12.5 days.
Conclusion Upper extremity free flap transfers could be performed with a low rate of 30-day complications, reoperations, and readmissions.
Keywords: upper extremity free flap, NSQIP, flap complications, flap outcomes
Introduction
Management of complex upper extremity injuries with severe soft tissue loss is quite challenging, necessitating a multifaceted approach. 1 2 In a severely traumatized extremity in which limb salvage and soft tissue coverage are suspected, amputation was traditionally preferred, thereby prioritizing life over limb. 3 With the advancements in microsurgical technique, the focus has shifted to limb preservation following extremity injuries. 4 5 While local and pedicle flaps are sufficient for small defects of the upper extremity, high-energy mutilation or wide local resections are often unamenable to these treatment strategies and require functional free tissue transfers. 6 7
Free flaps offer significant versatility in reconstructive options for the upper extremity, and can include a variety of tissue types, depending on the desired coverage. 1 2 Therefore, flap selection is a complex and subjective process requiring a robust understanding of the defect being covered, donor site characteristics, aesthetics, patient preference, and the goals of reconstruction. 2 The outcomes of upper extremity free flap transfers have been variably described and mostly in a limited case series. 8 9 The literature concerning free flap survival is limited by the tremendous variability in the recipient site. 10 11 12 13
The purpose of this study was to study free tissue transfers in the upper extremity and specifically examine: (1) patient demographics, (2) flap characteristics, and (3) 30-day complication, readmission, and reoperation rates for all patients undergoing free flap transfer procedures of the upper extremity utilizing the American College of Surgeons’ National Surgical Quality Improvement Program (ACS NSQIP) database.
Materials and Methods
Database Usage
The NSQIP database was queried to identify all patients who underwent upper extremity free flap transfer procedures performed between 2008 and 2016. The NSQIP database is a prospectively collected, validated database that is comprised of perioperative data from patients undergoing operations at more than 600 American hospitals. 14 15 16 17 Specifically, trained clinical reviewers at NSQIP-participating institutions gather patient data from the preoperative and perioperative through 30-day postoperative periods. Patient information reported in the database includes demographics, comorbidities, laboratory, and intraoperative data, including the Current Procedural Terminology (CPT) codes for surgical procedures and International Classification of Disease 9 th (ICD-9) revision diagnosis codes for surgical indication(s). Furthermore, 30-day discharge dispositions, readmissions, reoperations, and patient mortalities are reported. 16 CPT codes corresponding to free flap transfer procedures were utilized to query the database ( Table 1 ). Patients were selected based on CPT codes corresponding to upper extremity free flap procedures; these included free skin, muscle, myocutaneous, and osteocutaneous flaps with microvascular anastomoses. Head and neck cases were excluded by identifying procedures in which the primary attending was an otolaryngologist. Patients were only included if a diagnostic or CPT code specific to the upper extremity was included.
Table 1. Demographic data and preoperative laboratory values for patients undergoing free flap transfers of the upper extremity.
| Demographic data | Amount |
|---|---|
| Abbreviations: BMI, body mass index; CHF, chronic heart failure; COPD, chronic obstructive pulmonary disease; INR, international normalized ratio. | |
| Number | 111 |
| Mean age (years) | 36.8 |
| Sex | |
| Male | 76.6% |
| Female | 23.4% |
| Race | |
| White | 78.4% |
| Black | 6.3% |
| Other | 15.3% |
| Preoperative conditions | |
| Mean BMI | 28.54 |
| Smoker within past year | 27.9% |
| Recent weight loss | 0% |
| Hypertension | 16.2% |
| Diabetes mellitus | 4.5% |
| COPD | 0% |
| Dialysis | 0% |
| CHF | 0% |
| Ascites | 0% |
| Demographic Data | Amount |
| Disseminated cancer | 0.9% |
| Preoperative sepsis | 0% |
| Preoperative laboratory values | |
| White blood-cell count | 7.56 |
| Hematocrit | 40.46 |
| Platelets | 248 |
| Creatinine | 0.817 |
| Albumin | 3.96 |
| INR | 1.16 |
| Operative variables | |
| Wound class | |
| Clean | 91.1% |
| Clean-contaminated | 2.7% |
| Contaminated | 1.8% |
| Dirty | 4.5% |
| ASA classification | |
| 1 (No disturbance) | 32.4% |
| 2 (Mild disturbance) | 56.8% |
| 3 (Severe disturbance) | 9.9% |
| 4 (Life-threatening disturbance) | 0.9% |
| Preoperative blood transfusions | 0% |
| Demographic Data | Amount |
| Operative time (minutes) | 346.95 |
| Length of stay (days) | 3.66 |
| Mean days from admission to operation (days) | 0.17 |
Statistical Analysis
A full, un-matched cohort was used for all the analyses performed. The complication, readmission, and reoperation rates within 30 days of the index procedure were identified. Due to yearly variations in data encoding, each variable of interest was redefined and standardized using the NSQIP Participant Use Data File corresponding to each year included. Demographic data including age, sex, and race were reported. Due to the infrequent occurrence of complications, statistical analysis between different flap groups was not performed. Therefore, descriptive analysis was utilized to report the occurrence of complications, readmissions, and reoperations after upper extremity free tissue transfer.
The mean operative time for the varying flap types was analyzed with two-way analysis of variance. For all statistical analysis, an α value of 0.05 was used as the threshold for significance. All statistical analysis was conducted in SPSS Statistics Version 24.0 (IBM Corporation, Armonk, New York, United States).
Results
After querying the NSQIP database, 111 patients were included in this study. The mean age was 36.8 years (range: 18–82 years), and 76.6% were men ( Table 1 ). About 78.4% of patients were white, 6.3% were black, and 15.3% were of other backgrounds. The mean body mass index of patients undergoing an upper extremity free flap transfer was 28.54 kg/m 2 . About 27.9% of patients reported smoking within the year prior to surgery. The most common medical comorbidities reported included hypertension (16.2%) and diabetes (4.5%). There were no patients with chronic obstructive pulmonary disease, end-stage renal disease requiring dialysis, corticosteroid use, preoperative sepsis, receiving radiation therapy, or preoperative blood transfusions. Most patients presented with a clean wound (91.1%). Further information regarding preoperative laboratory values and the comorbidities and wound classes is available in Table 1 .
The flap types performed were muscle or myocutaneous free flaps (45.9%), free fasciocutaneous flap (8.1%), fascial flap (2.7%), free vascularized bone graft with microanastomosis (1.8%), free metatarsal flap (10.8%), other free vascularized bone graft with microanastomosis (27.9%), and the free osteocutaneous flap (2.7%) ( Table 2 ). Of patients undergoing myocutaneous flaps, 52.9% of patients had a diagnosis of brachial plexus injury. The average patient underwent free tissue transfer on the first day of admission. Orthopaedic surgeons performed 50% of the free flaps with plastic surgeons performing an additional 42.3% of flaps. A minority of procedures were performed by general surgeons (4.5%), and neurosurgeons (2.7%). Plastic surgeons most commonly performed myocutaneous flaps (53.2%), while orthopaedic surgeons most commonly performed vascularized bone grafts (41.1%). Mean operative time was greatest in patients undergoing a vascularized fibular flap (448 minutes), while patients undergoing a free osteocutaneous flap from a metatarsal had the shortest mean operative duration (153 minutes) ( p < 0.001). The average patient length of stay for all procedures was 3.66 days ( Table 1 ). The nature of diagnoses necessitating the use of a free flap are detailed in Table 3 . The most frequent indication was a history of an injury to the brachial plexus (24.3%), with the second most common indications being nonunion of an unspecified fracture (21%). A total of three cases (2.7%) had neoplastic indications ( Table 3 ).
Table 2. Primary Current Procedural Terminology (CPT) codes of upper extremity free flaps used as inclusion criteria, with flap type frequency and comparison of operative times.
| Free flap type | CPT | Percentage performed | Operative time in minutes (SD) | p -Value (if applicable) |
|---|---|---|---|---|
| Abbreviations: SD, standard deviation. | ||||
| Free muscle or myocutaneous flap with microvascular anastomosis | 15756 | 45.9% | 433.65 (161.587) | – |
| Free skin flap with microvascular anastomosis | 15757 | 8.1% | 400.44 (157.326) | – |
| Free fascial flap with microvascular anastomosis | 15758 | 2.7% | 437 (224.72) | – |
| Bone graft with microvascular anastomosis; fibula | 20955 | 1.8% | 448 (192.333) | <0.0001 |
| Free osteocutaneous flap graft from metatarsal with microvascular anastomosis | 20972 | 10.8% | 152.75 (80.075) | |
| Bone graft with microvascular anastomosis; other than fibula, iliac crest, or metatarsal | 20962 | 27.9% | 239.19 (116.19) | – |
| Free osteocutaneous flap with microvascular anastomosis; other than iliac crest, metatarsal, or great toe | 20969 | 2.7% | 445.67 (310.775) | – |
| Free osteocutaneous flap graft from iliac crest with microvascular anastomosis | 20970 | – | – | – |
| Bone graft of pelvic bone with microvascular connection | 20956 | – | – | – |
| Free osteocutaneous flap graft from great toe with microvascular anastomosis | 20973 | – | – | – |
Table 3. Indication for flap among study cohort of patients undergoing free flap reconstruction.
| Indication for flap | Number of patients (%) |
|---|---|
| Injury of brachial plexus | 27 (24.3) |
| Nonunion of fracture | 24 (21) |
| Closed fracture of scaphoid | 8 (7.2) |
| Open wound of elbow complicated | 4 (3.6) |
| Contracture of hand | 3 (2.7) |
| Closed fracture of lower end of radius and ulna | 3 (2.7) |
| Malignant melanoma of upper limb | 2 (1.8) |
| Malunion of fracture | 2 (1.8) |
| Crushing injury of elbow | 1 (0.9) |
| Closed fracture of radius and ulna | 1 (0.9) |
| Full-thickness skin loss due to burn | 1 (0.9) |
| Malignant melanoma of skin | 1 (0.9) |
| Malignant neoplasm of scapula and/or long bones of upper limb | 1 (0.9) |
| Mononeuritis of upper limb | 1 (0.9) |
| Open wound of hand with tendon involvement | 1 (0.9) |
| Unspecified injury to hand | 1 (0.9) |
| Other mononeuritis of upper limb | 1 (0.9) |
| Pain in unspecified forearm joint | 1 (0.9) |
| Pathological dislocation of upper arm joint | 1 (0.9) |
| Secondary and unspecified malignant neoplasm of lymph nodes of axilla and upper limb | 1 (0.9) |
| Unspecified stiffness of forearm | 1 (0.9) |
| Unspecified stiffness of hand | 1 (0.9) |
| Volkmann’s ischemic contracture | 1 (0.9) |
| Not specified | 17 (15.0) |
The complications within 30 days following surgery included superficial surgical site infections (2.7%), pneumonias (0.9%), deep venous thromboses (0.9%), intraoperative transfusions (7.2%), and postoperative transfusions (6.3%). All patients who developed surgical site infections underwent myocutaneous flaps for brachial plexus injuries; in total 6% of patients undergoing myocutaneous flaps developed surgical site infections. The reoperation rate was 4.5%, and most commonly occurred for incision and drainage (1.8%), delayed closure of surgical wound (0.9%), flap debridement (0.9%), or other procedure(s) of the integumentary system (0.9%) ( Table 4 ). The readmission rate was 3.6% with only two patients readmitted for direct failure (0.9%) or flap infection (0.9%) ( Table 5 ).
Table 4. Postoperative complications following upper extremity free flap procedures.
| Complication | Percentage |
|---|---|
| Abbreviations: CVA, cerebrovascular accident; DVT, deep vein thrombosis; SSI, surgical site infection. | |
| DVT | 0.9 |
| Sepsis | 0 |
| Myocardial infarction | 0 |
| Cardiac arrest | 0 |
| Stroke/CVA | 0 |
| Urinary tract infection | 0 |
| Acute renal failure | 0 |
| Progressive renal insufficiency | 0 |
| Pulmonary embolism | 0 |
| Unplanned intubation | 0 |
| Pneumonia | 0.9 |
| Wound disruption | |
| Organ/space SSI | 0 |
| Deep incisional SSI | 0 |
| Superficial incisional SSI | 2.7 |
| Intraoperative transfusion | 7.2 |
| Postoperative transfusion | 6.3 |
Table 5. Frequency of reoperation and readmission and their indications following upper extremity free flap procedures.
| Reoperation and readmission data | Percentage |
|---|---|
| Abbreviation: ICD-9, International Classification of Disease 9th revision. | |
| Mean days from operation to readmission | 12.5 days |
| Reoperation rate | 4.5 |
| Reoperations | |
| Incision and drainage | 1.8 |
| Secondary closure of surgical wound or dehiscence, extensive or complicated | 0.9 |
| Debridement | 0.9 |
| Complex procedure on the integumentary system | 0.9 |
| Rate of two reoperations | 0 |
| Readmission percentage | 3.6 |
| Readmission for suspected flap failure | 0.9 |
| Readmission ICD-9 codes | |
| Pleural effusion | 0.9 |
| Fever or other disturbance of temperature regulation | 0.9 |
| Infected post-op serosa | 0.9 |
Discussion
Free flaps of the upper extremity are a viable procedure for soft tissue defects not suited for local coverage. 1 2 Literature previously published is inconsistent, generalizing and combining free-flap data for multiple recipient sites. 18 19 While the NSQIP database has been utilized in previous reports, our study mainly focuses on free tissue transfers of the upper extremity. 10 11 13 Free tissue transfers of the upper extremity were infrequent, with only 111 cases reported within an 8-year period. The cases within the NSQIP database identified a relatively young and physiologically healthy cohort without significant medical comorbidities. While the national prevalence of hypertension and diabetes mellitus is 29.3 and 7.9%, respectively, the prevalence of these diseases within NSQIP free flap transfer recipients was significantly lower. 20 21 As nearly 90% of the transfer recipients were graded as American Society of Anaesthesiologists’ (ASA) classification 1 or 2, it was likely that upper extremity trauma was the common inciting factor for these patients; however, this is an inference and not explicitly reported by the database.
The frequency of revision procedures was remarkably small in this study. Five patients, comprising 4.5% of the study cohort, required a revision procedure. A similar revision rate of 4.4% has been documented in a larger case-series studying breast free flap reconstruction. 22 Recently, Kim et al conducted a database study with a sample size of 6,030 patients and reported a 14.2% reoperation and a 0.5% flap failure rate. 5 However, the recipient sites varied tremendously with breast reconstruction representing over 70% of the cases reported. 5 Similarly, a study examining the NSQIP dataset reported upon 674 patients with a free flap transfer, not limited to the upper extremity, and documented a 17.9% total reoperation and 6% flap failure rate. 11 In comparison, this study reports a smaller reoperation and flap failure rate (0.9%), which might suggest free flap transfers outside of the upper extremity are more susceptible to complication. As such, generalizing the results of previous NSQIP studies on free tissue transfers to the upper extremity may provide an inaccurate complication and reoperation rate.
Complications aside from the need for intraoperative transfusion were uncommon ( Table 4 ). These results differed from previous reports, such as Klosterman et al, which in 2015 had complication rates as high as 60% for free flap transfers of the head and neck. 23 Differences in complication rates may be reflective of increased difficulty due to differing operative indications. Free flap transfers of the upper extremity are more common in the traumatic setting, while free tissue transfers to the head and neck are typically indicated for oncologic defects. 24 25 In Klosterman et al, they reviewed the results of free flaps to the head and neck at a single institution over 20 years. They reported performing 88% of such reconstructive flaps for oncologic pathologies, and only 6% due to traumas 23 ; their surgical indications were, therefore, likely vastly different than patients included in this study. As such, the difference in reported complication rates may stem from the differences in procedural indications and systemic patient health. Further investigation into how differences in recipient site pathology relate to complication rate is warranted.
There are several limitations in this study. These data are inherently limited by the quality of reporting and standardization of the dataset provided by the NSQIP. The authors were unable to definitively comment on the mechanism of injury necessitating free flap transfer, but we can infer from postoperative diagnosis codes that the majority the flaps were in the setting of trauma. While the majority of flaps was on the first day of admission, it is likely that these flaps were planned procedures with an antecedent trauma admission in which the patient did not undergo definitive surgical management; as such, data related to the patient’s preoperative condition, including neurovascular status, or time from initial injury, are not available. Additionally, the study is limited by the nature of the NSQIP database; given its genesis as a database to engender quality improvement, thus collected data may not include clinical details subspecialists such as plastic and reconstructive surgery. Along these lines, specifics regarding the nature of reoperations, such as exploration of the pedicle or anastomotic revision, may not be captured. Instead, such a procedure may be simply coded as an unspecified reoperation.
Moreover, the sample size of the study was limited. Strict inclusion criteria to select only procedures related to the upper extremity were instituted, yet these were limited by the nature of the CPT codes, as some codes utilized for these flaps are not unique to the upper extremity or it could not be determined whether the coded procedure was specific to the upper extremity. Furthermore, there was such variability in free flap reconstruction, which cannot be identified in a database study. Success of free flap reconstruction is not only predicated on microsurgical technique or donor/recipient characteristics but also requires a multidisciplinary approach with adequate institutional/ancillary support including specialized nursing, continuous flap monitoring, and resources to contend with immediate complications. These subtleties could not be highlighted in a database study and may account for differences in complication/success rates observed across different institutions. Additionally, complication rates were limited to 30 days which, in the setting of flap failure, are likely encompassing; but secondary procedures were under-identified, given they can occur years after the index procedure and may often be related to the trauma itself. Successful free tissue transfer did not infer a functional limb with satisfactory patient outcomes but represents one important facet in a series of multiple steps required for successful upper extremity reconstruction.
Conclusion
In a sample of 111 patients undergoing free flap reconstruction across multiple institutions with variable protocols, the complication rate was very low. Despite the limited sample size of this study, we demonstrate free tissue transfers to be a safe and efficacious treatment strategy for soft tissue injuries of the upper extremity, with a limited complication profile within 30 days of the index procedure. Despite the variability in graft type and surgical technique, free flap reconstruction can provide soft tissue coverage for upper extremity defects unable to be locally treated. 1 2 Future studies should aim to investigate upper extremity flap reconstruction in a prospective, multicentric fashion to help further delineate perioperative characteristics associated with successful free tissue transfer.
Footnotes
Conflict of Interest The following authors have nothing to disclose: G.A.B., K.D., N.V.S., J.P.S., and J.M.N. S.K.M.. disclose personal fees (presenter or speaker) from Integra LifeScience. S.M.K. discloses unpaid consultancy with TriMed Inc. and discloses personal fees (consultant) from Integra LifeScience.
References
- 1.Gupta A, Lakhiani C, Lim B H. Free tissue transfer to the traumatized upper extremity: risk factors for postoperative complications in 282 cases. J Plast Reconstr Aesthet Surg. 2015;68(09):1184–1190. doi: 10.1016/j.bjps.2015.05.009. [DOI] [PubMed] [Google Scholar]
- 2.Kelley B P, Chung K C. Soft-tissue coverage for elbow trauma. Hand Clin. 2015;31(04):693–703. doi: 10.1016/j.hcl.2015.06.013. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Sabapathy S R, Elliot D, Venkatramani H. Pushing the boundaries of salvage in mutilating upper limb injuries: techniques in difficult situations. Hand Clin. 2016;32(04):585–597. doi: 10.1016/j.hcl.2016.06.003. [DOI] [PubMed] [Google Scholar]
- 4.Garcia R M, Ruch D S. Free flap functional muscle transfers. Hand Clin. 2016;32(03):397–405. doi: 10.1016/j.hcl.2016.03.009. [DOI] [PubMed] [Google Scholar]
- 5.Kim J Y, Subramanian V, Yousef A, Rogers B A, Robb G L, Chang D W. Upper extremity limb salvage with microvascular reconstruction in patients with advanced sarcoma. Plast Reconstr Surg. 2004;114(02):400–408. doi: 10.1097/01.prs.0000131987.40578.7b. [DOI] [PubMed] [Google Scholar]
- 6.Tamai S, Komatsu S, Sakamoto H, Sano S, Sasauchi N. Free muscle transplants in dogs, with microsurgical neurovascular anastomoses. Plast Reconstr Surg. 1970;46(03):219–225. doi: 10.1097/00006534-197009000-00002. [DOI] [PubMed] [Google Scholar]
- 7.Terzis J K, Vekris M D, Soucacos P N. Outcomes of brachial plexus reconstruction in 204 patients with devastating paralysis. Plast Reconstr Surg. 1999;104(05):1221–1240. doi: 10.1097/00006534-199910000-00001. [DOI] [PubMed] [Google Scholar]
- 8.Spindler N, Al-Benna S, Ring A. Free anterolateral thigh flaps for upper extremity soft tissue reconstruction. GMS Interdiscip Plast Reconstr Surg DGPW. 2015;4:Doc05. doi: 10.3205/iprs000064. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Scaglioni M F, Lindenblatt N, Barth A A, Fuchs B, Weder W, Giovanoli P. Free fillet flap application to cover forequarter or traumatic amputation of an upper extremity: a case report. Microsurgery. 2016;36(08):700–704. doi: 10.1002/micr.30124. [DOI] [PubMed] [Google Scholar]
- 10.Kantar R S, Rifkin W J, David J A.Diabetes is not associated with increased rates of free flap failure: analysis of outcomes in 6030 patients from the ACS-NSQIP database Microsurgery 2018(February)1–10. [DOI] [PubMed] [Google Scholar]
- 11.Kim B D, Ver Halen J P, Mlodinow A S, Kim J YS. Intraoperative transfusion of packed red blood cells in microvascular free tissue transfer patients: assessment of 30-day morbidity using the NSQIP dataset. J Reconstr Microsurg. 2014;30(02):103–114. doi: 10.1055/s-0033-1357275. [DOI] [PubMed] [Google Scholar]
- 12.Louer C R, Garcia R M, Earle S A, Hollenbeck S T, Erdmann D, Levin L S. Free flap reconstruction of the knee: an outcome study of 34 cases. Ann Plast Surg. 2015;74(01):57–63. doi: 10.1097/SAP.0b013e31828d7558. [DOI] [PubMed] [Google Scholar]
- 13.Cannady S B, Hatten K M, Bur A M. Use of free tissue transfer in head and neck cancer surgery and risk of overall and serious complication(s): an American College of Surgeons-National Surgical Quality Improvement Project analysis of free tissue transfer to the head and neck. Head Neck. 2017;39(04):702–707. doi: 10.1002/hed.24669. [DOI] [PubMed] [Google Scholar]
- 14.American College of Surgeons. Participant Use Data File. American College of Surgeons National Surgical Quality Improvement Program
- 15.Shiloach M, Frencher SK J r, Steeger J E. Toward robust information: data quality and inter-rater reliability in the American College of Surgeons National Surgical Quality Improvement Program. J Am Coll Surg. 2010;210(01):6–16. doi: 10.1016/j.jamcollsurg.2009.09.031. [DOI] [PubMed] [Google Scholar]
- 16.Khuri S F, Daley J, Henderson W. National VA Surgical Quality Improvement Program. The Department of Veterans Affairs’ NSQIP: the first national, validated, outcome-based, risk-adjusted, and peer-controlled program for the measurement and enhancement of the quality of surgical care. Ann Surg. 1998;228(04):491–507. doi: 10.1097/00000658-199810000-00006. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Hall B L, Hamilton B H, Richards K, Bilimoria K Y, Cohen M E, Ko C Y. Does surgical quality improve in the American College of Surgeons National Surgical Quality Improvement Program. Trans. Meet Am Surg Assoc. 2009;127(03):7–20. doi: 10.1097/SLA.0b013e3181b4148f. [DOI] [PubMed] [Google Scholar]
- 18.Kapoor T, Banuelos J, Adabi K, Moran S L, Manrique O J. Analysis of clinical outcomes of upper and lower extremity reconstructions in patients with soft-tissue sarcoma. J Surg Oncol. 2018;118(04):614–620. doi: 10.1002/jso.25201. [DOI] [PubMed] [Google Scholar]
- 19.Landau M J, Badash I, Yin C, Alluri R K, Patel K M. Free vascularized fibula grafting in the operative treatment of malignant bone tumors of the upper extremity: a systematic review of outcomes and complications. J Surg Oncol. 2018;117(07):1432–1439. doi: 10.1002/jso.25032. [DOI] [PubMed] [Google Scholar]
- 20.Ong K L, Cheung B MY, Man Y B, Lau C P, Lam K SL. Prevalence, awareness, treatment, and control of hypertension among United States adults 1999-2004. Hypertension. 2007;49(01):69–75. doi: 10.1161/01.HYP.0000252676.46043.18. [DOI] [PubMed] [Google Scholar]
- 21.Mokdad A H, Ford E S, Bowman B A. Prevalence of obesity, diabetes, and obesity-related health risk factors, 2001. JAMA. 2003;289(01):76–79. doi: 10.1001/jama.289.1.76. [DOI] [PubMed] [Google Scholar]
- 22.Vanschoonbeek A, Fabre G, Nanhekhan L, Vandevoort M. Outcome after urgent microvascular revision of free DIEP, SIEA and SGAP flaps for autologous breast reconstruction. J Plast Reconstr Aesthet Surg. 2016;69(12):1598–1608. doi: 10.1016/j.bjps.2016.09.017. [DOI] [PubMed] [Google Scholar]
- 23.Klosterman T, Siu E, Tatum S. Free flap reconstruction experience and outcomes at a low-volume institution over 20 years. Otolaryngol Head Neck Surg. 2015;152(05):832–837. doi: 10.1177/0194599815573726. [DOI] [PubMed] [Google Scholar]
- 24.Cannady S B, Rosenthal E L, Knott P D, Fritz M, Wax M K. Free tissue transfer for head and neck reconstruction: a contemporary review. JAMA Facial Plast Surg. 2014;16(05):367–373. doi: 10.1001/jamafacial.2014.323. [DOI] [PubMed] [Google Scholar]
- 25.Fischer J P, Elliott R M, Kozin S H, Levin L S. Free function muscle transfers for upper extremity reconstruction: a review of indications, techniques, and outcomes. J Hand Surg Am. 2013;38(12):2485–2490. doi: 10.1016/j.jhsa.2013.03.041. [DOI] [PubMed] [Google Scholar]