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Source
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| University
of Texas M. D. Anderson Cancer Center
Volume: n/a
Number: n/a
May 1999 |
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Index
Effect of Obesity on Flap and Donor-Site
Complications in Free Transverse Rectus Abdominis Myocutaneous
Flap Breast Reconstruction - Commentary by R.J. Allen,
M.D.
Effect of Smoking on Complications
in Patients Undergoing Free TRAM Flap Breast Reconstruction
Effect of Obesity on Flap and Donor-Site
Complications in Free Transverse Rectus Abdominis Myocutaneous
Flap Breast Reconstruction
Effect of Obesity on Flap and Donor-Site
Complications in Free Transverse Rectus Abdominis Myocutaneous
Flap Breast Reconstruction
Commentary by R.J. Allen, M.D.
According to Chang, Wang, Robb, et al., 97% of obese
patients in their study who underwent autologous tissue
breast reconstruction had a successful outcome. At the
same time, compared with normal-weight patients, obese
patients also experienced four times the rate of abdominal
hernia, which largely may have been preventable. By
excising the rectus abdominis muscle, the surgeons removed
a crucial structure whose natural function is to retain
abdominal contents. Morbidity could have been significantly
reduced or eliminated by using a deep inferior epigastric
perforator (DIEP) or superficial inferior epigastric
artery (SIEA) free fla, in which abdominal fat and skin
is removed to reconstruct the breast wile leaving the
rectus abdominis muscle intact. In the obese patient,
the DIEP or SIEA free flap breast reconstruction would
have the added benefit of doubling as a pannulectomy,
a well-recognized treatment to improve functional mobility
in the morbidity obese. The authors correctly concluded
that obesity should not be considered a contraindication
to autologous tissue breast reconstruction, but ultimately
the best method of breast reconstruction to reduce morbidity
and improve function-particularly in the obese-is the
DIEP or SIEA flap breast reconstruction.
R.J. Allen, M.D.
Effect of Smoking on Complications
in Patients Undergoing Free TRAM Flap Breast Reconstruction
Smoking has long been considered a relative contraindication
for autogenous tissue breast reconstruction, due in
part to the vasoconstrictive effects of nicotine, tissue
hypoxia from carbon monoxide in cigarettes, and blood
hypercoagulability caused by increased platelet aggregation.
Similar to the results reported by Chang, Reece, Wang,
et al., in our series of 343 patients with deep inferior
epigastric perforator (DIEP) flap breast reconstruction
we found fat necrosis to be more than four times as
conunon in smokers as non- smokers and delayed abdominal
wound healing to be three times as common in smokers
as non-smokers. Like the surgeons at MD Anderson we
request patients electing autogenous tissue breast reconstruction
to stop smoking at least 3-4 weeks prior to surgery,
as after this period the postoperative complication
rate among former smokers becomes comparable to that
of nonsmokers. Indeed, Chang, Reece, Wang, et al also
report a three times higher incidence of abdominal hernia
among smokers as compared to non-smokers, and consistent
with their hypothesis that this may be due in part to
excessive postoperative coughing and increased tension
at the abdominal fascial closure, former smokers who
have quit at least 4 weeks prior to surgery reduce their
incidence of abdominal hernia to a rate almost as low
as non-smokers. Yet the baseline rate of abdominal hernia
is different among patients who sacrifice their rectus
abdominis muscle to undergo a myocutaneous free flap
breast reconstruction and those who retain their rectus
abdominis muscle to undergo a free perforator flap breast
reconstruction. Even considering only the best case
scenario, the non-smokers and former smokers in this
series still reported more than double the incidence
of abdominal hernia as all patients-including smokers
and non-smokers-in our series of 551 patients who retained
their rectus abdomuns muscle. By preserving the rectus
abdominis muscle, the DIEP flap largely avoids the problem
of abdominal herniation by allowing the abdominal wall
to remain competent. Better still is the superficial
inferior epigastric artery (SIEA) free flap, which minimizes
donor morbidity even ftuther by making it unnecessary
to penetrate the fascial layer. Thus, while we agree
that smoking cessation 3-4 weeks prior to surgery is
an important therapy to reduce complications in free
flap breast reconsftiicfions, ultimately the best way
to minimize postoperative complications such as abdominal
herniation is via the DIEP or SIEA free flap breast
reconstruction.
RJ Allen
CM Chen
Effect of Obesity on Flap
and Donor-Site Complications in Free Transverse Rectus
Abdominis Myocutaneous Flap Breast Reconstruction
David W. Chang, M.D., Bao-guang Wang, M.D., Ph.D., Geoffrey
L. Robb, M.D., Gregory P. Reece, M.D., Michael J. Miller,
M.D., Gregory R.D. Evans, M.D., Howard N. Langstein,
M.D., and Stehen S. Kroll, M.D.
Houston, Texas
The purpose of this study was to assess the effect
of obesity on flap and donor-site complications in patients
undergoing free transverse rectus abdominis myocutaneous
(TRAM) flap breast reconstruction. All patients undergoing
breast reconstruction with free TRAM flaps at our institution
from February 1, 1989, through May 31,1998, were reviewed.
Patien@s were divided into three groups based on their
body mass index: normal (body mass index <25), overweight
(bodv mass index 25 to 29),(body mass index >30).
Flap and donor-site complications in the three groups
were compared.
A total of 936 breast reconstructions with free TRM
flaps were performed in 718 patients. There were 442
(61.6 percent) normal-weight. 212 (29.5 percent) over-weight,
and 64 (8.9 percent) obese patients. Flap complications
occurred in 222 of 936 flaps (23.7 percent). Compared
with normal-weight patients, obese patients had a significantly
higher rate of overall flap complications (39.1 versus
20.4 percent; p=0.001), total flap loss (3.2 versus
0 percent; p=0.0001), flap seroma (10.9 versus 3.2 percent;
p=0.004), and mastectomy flap necrosis (21.9 versus
6.6 percent; p=0.001). Similarly, overweight patients
had a significantly higher rate of overall flap complications
(27.8 versus 20.4 percent; p=0.033), total flap loss
(1.9 versus 0 percent p=0.004), flap hematoma (0 versus
3.2 percent; p=0.007), and mastectomy flap necrosis
(15.1 versus 6.6 percent; p=0.001) compared with normal-weight
patients. Donor-site complications occurred in 106 of
718 patients (14.9 percent). Compared with normal-weight
patients, obese patients had a significantly higher
rate of overall donor-site complications (23.4 versus
11.1 percent; p=0.005), infection (4.7 versus 0.5 percent;
p=0.016), seroma (9.4 versus 0.9 percent; P<0.001),
and hernia (6.3 versus 1.6 percent; p=0.039). Similarly,
overweight patients had a significantly higher rate
of overall donor-site complications (19.8 versus 11.1
percent; p=0.003), infection (2.4 versus 0.5 percent:
p=0.039), bulge (5.2 versus 1.8 percent: p=0.016), and
hernia (4.3 versus 1.6 percent: p=0.039) compared with
normal-weight patients. There were no significant differences
in age distribution, smoking hsitory, or comorbid conditions
among the three groups of patients. Obese patients.
however, had a significantly higher incidence of preoperative
radiotherapy and preoperative radiotherapy and preoperative
chemotherapy than did patients in the other two groups.
A total of 23.4 percent of obese patients had preoperative
radiation therapy compared with 12.3 percent of overweight
patients and 12.4 percent of normal-weight patients;
34.4 percent of obese patients had preoperative chemotherapy
compared with 24.5 percent of overweight patients and
17.7 percent of normal-weight patients. Multiple logistic
regression analysis was used to determine the risk factors
for flap and donor-site complications while simultaneously
controlling for potential confounding factors, including
the incidence of preoperative chemotherapy and radiotherapy.
In summary, obese and overweight patients undergoing
breast reconstruction with free TRAM flaps had significantly
higher total flap loss. flap hematoma, flap seroma,
mastectomy skin flap necrosis, donor-site infection,
donor-site seroma, and hernia compared with normal-
weight patients. There were no significant differences
in the rate of partial flap loss, vessel thrombosis,
fat necrosis, abdominal flap necrosis, or umbilical
necrosis between any of the groups.
The majority of overweight and even obese patients
who undertake breast reconstruction with free TRAM flaps
complete the reconstruction successfully. Both such
patients and surgeons, however, must clearly understand
that the risk of failure and complications is higher
than in normal-weight patients. Patients who are morbidly
obese are at a high risk of failure and complications
and should avoid any type of TRAM flap breast reconsruction.
(Plast. Reconstr. Surg. 105: 1640. 2000.)
Obesity is generally considered a contraindication
for pedicled transverse rectus abdominis myocutancous
(TRAM) flap breast reconstruction. (1,2) It is believed
that pedicled TRAM flap breast reconstruction in markedly
obese patients is associated with unacceptably high
rates of flap and donor-site morbidity (1-4). For obese
and other high-risk patients, such as heavy smokers,
the free TRAM flap is often advocated for breast reconstruction,
(3,5-13)
Use of the free TRAM flap for breast reconstruction
was first described by Holmstrom in 1979. (14) With
the free TRAM flap, the deep inferior epigastric system
is used to maximize the blood flow of the flap. In addition,
less donor-site sacrifice is required; less extensive
abdominal undermining is needed as well as less sacrifice
of abdominal fascia and muscle. The better blood supply
and the limited donor-site sacrifice are said to result
in lower complication rates than are seen with use of
the pedicle TRAM flap in these high-risk patients. (3,9-15)
However, many consider obesity to be a relative contraindication
to free TRAM flap reconstruction as well. (3,6-8,10,11)
It is believed that the large and heavy abdominal flap
stretches and attenuates the musculocutaneous perforators,
thus compromising blood supply to the flap. (1) Although
the increased surgical risks in obese-patients with
other procedures are well documented, the risks of free
TRAM flap breast reconstruction in obese patients have
never been quantified. (16-21) Whether use of the free
TRAM flap is a desirable option for breast reconstruction
in obese patients is still unclear.
In this study, we reviewed our experience at the University
of Texas M. D. Anderson Cancer Center with free TRAM
flap breast reconstruction to determine whether flap
and donor-site complications were more common in obese
and overweight patients than in normal-weight patients.
As a result, we hoped to address the following questions:
'What are the risks of free TRAM flap breast reconstruction
in overweight and obese patients? Should we be doing
free TRAM flap breast reconstruction in overweight and
obese patients?
Patients and Methods
All patients who underwent breast reconstruction with
free TRAM flaps at the M. D. Anderson Cancer Center
between February 1, 1989, and May 31, 1998, were reviewed.
All data reviewed had been collected prospectively and
entered into a computerized database. Patients were
divided into three groups on the basis of their body
mass index [weight (kg)/ height (M)2]: normal (body
mass index <25), overweight (body mass index 25 to
29.9), and obese (body mass index >30). Patients
were originally divided into five body mass index groups
according to the recommendation of the International
Obesity Task Force: thin (body mass index <18.5),
normal (body mass index 18.5 to 24.9), overweight (body
mass index 25.0 to 29.9), obese (body mass index 30.0
to 39.9), and morbidly obese (body mass index > 40.0).(22)
Owing to the relatively small number of patients in
the categories of thin and morbidly obese, these categories
were combined with the normal and obese categories,
respectively.
Flap and donor-site complications in the three groups
were compared. Flap complications evaluated included
partial and total flap loss, vessel thrombosis, flap
hematoma, flap infection, flap seroma, TRAM flap fat
necrosis, and mastectomy skin flap necrosis. Donor-site
complications evaluated included abdominal flap necrosis,
umbilical necrosis, hematoma, infection, seroma, bulge,
and hernia.
Information on demographic characteristics, smoking
history, other comorbid medical conditions, and preoperative
radiotherapy and chemotherapy was used to perform multivariate
statistical analysis. Comorbid conditions included were
diabetes, hypertension, cerebrovascular disease, peripheral
vascular disease, coronary artery disease, arrhythmias,
chronic obstructive lung disease, and congestive heart
failure.
Statistical Analysis
We used descriptive statistics, such as mean, SD, and
percentage, to compare patient subgroups. We also compared
the characteristics of the patients among subgroups
using the chi-square test to identify potential confounding
factors. We calculated the incidence of each individual
complication and the overall incidence of complications.
The incidence of donor-site complications was calculated
on the basis of patients, whereas the incidence of flap
complications was calculated on the basis of flaps.
Multiple logistic regression analysis was used to determine
the risk factors for flap and donor-site complications
while simultaneously controlling for potential confounding
factors. We presented both full model and final model
to show the impact of potential confounding factors
on the incidence of flap and donor-site complications.
Full model included overweight, obesity, preoperative
radiotherapy, and preoperative chemotherapy. Final model
contained the risk factors for flap and donor-site complications
and was selected using the step-wise method. The logistic
regression analyses were based on the number of patients
for both flap and donor-site complications. A p value
of less than 0.05 was considered statistically significant.
No correction was made for multiple testing in Tables
I through IV. In Tables V and VI, 95 percent confidence
interval for odds ratio that did not include 1 was considered
statistically significant. The Statistical Analysis
System software package (SAS Institute, Inc., Cary,
N.C.) was used for all analyses.
Results
During the study period, 936 breast reconstructions
with free TRAM flaps were performed in 718 patients;
80.9 percent were immediate and 23.3 percent were bilateral.
A total of 442 patients (61.6 percent) were in the normal-weight
group, 212 patients (29.5 percent) were in the overweight
group, and 64 patients (8.9 percent) were in the obese
group (Table 1). There were no significant differences
in age distribution, smoking history, or comorbid conditions
among the three groups of patients. Obese patients,
however, had a significantly higher incidence of preoperative
radiotherapy and preoperative chemotherapy than did
patients in the other two groups. A total of 23.4 percent
of obese patients had preoperative radiation therapy
compared with 12.3 percent of overweight patients and
12.4 percent of normal-weight patients. Also, 34.4 percent
of obese patients had preoperative chemotherapy compared
with 24.5 percent of overweight patients and 17.7 percent
of normal-weight patients.
Overall Complication Rates
Flap and donor-site complications are shown in Table
II. Flap complications occurred in 222 (23.7 percent)
of 936 flaps. The most common flap complication was
mastectomy skin flap necrosis (10.3 percent). The rate
of total flap loss was 0.9 percent, and the rate of
TRAM flap fat necrosis was 5.9 percent.
Donor-site complications occurred in 106 (14.8 percent)
of 718 patients. The most common donor-site complication
was umbilical necrosis (5.4 percent).
Flap Complications by Subgroups
Flap complications were significantly more common in
obese patients and overweight patients than in normal-weight
patients (Table III). Compared with normal-weight patients,
obese patients had significantly higher rates of overall
flap complications (p = 0.001), total flap loss (p =
0.001), flap seroma (p = 0.004), and mastectomy, flap
necrosis (p = 0.001). No significant differences were
noted in the rates of partial flap loss, vessel thrombosis,
hematoma, infection, or fat necrosis.
Compared with normal-weight patients, overweight patients
had significantly higher rates of overall flap complications
(p = 0.033), total flap loss (p = 0.004), and mastectomy
skin flap necrosis (p = 0.001). Normal-weight patients,
however, had a significantly higher rate of flap hematoma
compared with overweight patients (p = 0.007). No significant
differences were noted in the rates of partial flap
loss, vessel thrombosis, infection, seroma, or fat necrosis.
Donar-Site Complications by Subgroup
Donor-site complications were significantly more common
in obese patients and overweight patients than in normal-weight
patients (Table IV). Compared,with normal-weight patients,
obese patients had significantly higher rates of overall
donor-site complications (p = 0.005), infection (p =
0.016), seroma (p < 0.001), and heri-iia (p = 0.039).
No significant differences were noted in the rates of
abdominal flap necrosis, umbilical necrosis, hematoma,
or abdominal bulging.
Compared with normal-weight patients, overweight patients
had significantly higher rates of overall donor-site
complications (p = 0.003), infection (p = 0.039), bulge
(p = 0.016), and hernia (p = 0.039). No significant
differences were noted in the rates of abdominal flap
necrosis, umbilical necrosis, hernatoma, or seroma.
Tables V and VI show that obesity and being overweight
were significant risk factors for increase in complications
after controlling for preoperative radiation and chemotherapy.
Discussion
The increase in surgical risk for obese patients is
well known. Postoperative complications, such as wound
infections, poor tissue healing, and cardiopulmonary
complications, are found more frequently in obese patients.(16-21)
Obesity has also been associated with increased morbidity
in patients undergoing pedicled TRAM flap breast reconstruction.(1-4)
In fact, most consider obesity to be a contraindication
for pedicled TRAM flap breast reconstruction. However,
the status of obesity as a contraindication for free
TRAM flap breast reconstruction has been unclear. Free
TRAM flaps offer the advantages of improved blood supply
to the flap and reduced abdominal donor-site sacrifice.
Associated morbidity might be low enough to perform
free TRAM flaps for breast reconstruction in obese patients.
In reviewing our experience, we found that both flap
and donor-site complication rates were significantly
higher in obese patients undergoing free TRAM flap breast
reconstruction than in normal-weight patients undergoing
the procedure (Figs. 1 and 2). Obese patients had about
twice the flap and donor-site complication rates of
normal-weight patients. Over-weight patients also had
significantly higher complication rates than normal-weight
patients, although the rates were not as high as those
in obese patients.
Although obese patients were noted to have a higher
incidence of preoperative radiotherapy and preoperative
chemotherapy than patients in the other two groups,
we do not believe this played a significant role in
higher flap-related complications found in obese patients.
In our experience, we have not found significantly higher
flap-related complications in patients undergoing free
TRAM flap breast reconstruction after radiotherapy or
chemotherapy. (23,24) In addition, our data were evaluated
using multivariate statistical analysis to account for
other potential confounding factors, including the incidence
of preoperative chemotherapy and radiotherapy.
Flap Loss
Obese and overweight patients had significantly higher
rates of total flap loss than normal-weight patients
(Fig. 3). Because no significant differences in vessel
thrombosis were noted among the three groups, it seems
that the higher rates of flap loss in obese and over-weight
patients were most likely the result of less successful
salvage of ischemic flaps in these patients. Some believe
that the large and heavy abdominal flap in obese patients
stretches and attenuates the musculocutaneous perforators,
thus compromising blood supply to the flap.(1) This
may explain why the ischemic flaps are difficult to
salvage in obese patients. If the source of the problem
is at the perforators and not at the anastomoses, then
merely revising the anastomoses would not be sufficient
to revive the ischemic flap.
With large TRAM flaps, a careful attention in handling
the flap during the elevation and insetting may prevent
potential stretching of the perforators by the weight
of the heavy flap. One may consider tacking the edge
of the fascia to the flap with sutures to minimize accidental
attenuation of the perforators during the harvesting
of the flap. Also, securing the flap to the chest wall
during the insetting, especially at the superior border,
may reduce the tension placed on the perforators by
the weight of the flap. Postoperatively, use of a brassiere
to support the breast may be helpful. However, one must
be cautious of the potential compression of the vascular
pedicle by the use of brassiere during the early postoperative
period.
Fat Necrosis
Fat necrosis is defined as the formation of a small
firm area of scar tissue in the periphery of a flap
caused by, ischemic necrosis of subcu- taneous fat in
the absence of necrosis of overlying flap skin.(25)
Consistent with the previous report by the senior author,(25)
no significant increase in fat necrosis was noted in
either obese or overweight patients. Although obese
and overweight patients are at higher risk for flap
loss, at 96.8 and 98.1 percent success rate, respectively,
free TRAM flaps in these patients are still well vascularized
tissue, indicated by relatively low incidence of fat
necrosis.
Hematoma, Infection, and Seroma
The incidence of hematoma was not increased in obese
or overweight patients. Actually, the flap hematoma
rate was significantly lower in obese and overweight
patients than in normal-weight patients. Although it
is possible that small hematomas under the large flaps
may be harder to detect, clinically significant hematomas
would have been noted. Perhaps the less robust blood
flow relative to the volume of the obese flaps in obese
patients led to less likelihood of bleeding from the
flaps and thus the lower incidence of hematoma. However,
as expected, flap and donor-site seroma rates were significantly
higher in obese patients (Figs. 4 and 5). As the sizes
of the defect and the flap are usually larger in obese
patients, these patients are more susceptible to seroma
formation.
We found significantly higher donor-site infection
rates in obese and overweight patients than in normal-weight
patients (Fig. 6). The increased risk of surgical wound
infections for obese patients is well known.(16) We
did not, however, find significantly higher flap infection
rates in obese and overweight patients than in normal-weight
patients. This may be attributed to well-vascularized
free TRAM flap, even in obese patients.
Mastectomy Skin Rap Necrosis
Obese and overweight patients had proportionally higher
rates of skin flap necrosis, as expected (Fig. 7). Heavier
patients tend to have larger breast skin envelopes.
In addition, the tension on the mastectomy skin flaps
is expected to be greater from the heavy, larger TRAM
flaps. Thus, it is not surprising that obese patients
are at higher risk of mastectomy skin flap necrosis.
Abdominal Flap Necrosis and Umbilical Necrosis
As previously reported,(3) obese patients did not have
a higher incidence of abdominal flap or umbilical necrosis.
With free TRAM flaps, less undermining of the abdominal
flap is needed, and less sacrifice of rectus fascia
is required. Thus, the damage to the vascularity of
the abdominal flap and umbilicus is minimized.
Hernia and Abdominal Bulge
We defined an abdominal bulge as any asymetric abdominal
bulging.(4) Hernia was defined as dehiscence of the
fascial closure. Obese and overweight patients had significantly
higher rates of hernia than did normal-weight patients
(Fig. 8). In addition, over-weight patients had a higher
incidence of abdominal bulging than did normal-weight
patients. These findings are consistent with previous
reports regarding higher risk in obese patients with
abdominal surgery.(16-21) Several factors in obese patients
may, lead to increased healing problems of the abdominal
fascia. Obese patients often have increased tension
at the fascial closure. The increased risk of postoperative
pulmonary complications associated with general anesthesia
in these patients may further add to tension at the
fascia. Furthermore, the tissue quality of the fascia
in obese patients is often poor. As, a result, the abdominal
fascia may stretch and become thin, leading to an abdominal
bulge. Worse yet, the fascial closure may come undone,
or it may tear next to the closure, leading to hernia.
Summary
Obese patients had significantly higher flap and donor-site
complications than normal-weight patients. Specifically,
compared with normal-weight patients, obese patients
had more than three times the rate of total flap loss,
flap seroma, and mastectomy skin flap necrosis, more
than four times the rate of abdominal hernia, and more
than nine times the rate of donor-site infection and
seroma.
Overweight patients also had significantly higher flap
and donor-site complications than normal-weight patients.
Specifically, compared with normal-weight patients,
overweight patients had approximately twice the rate
of total flap loss, mastectomy, skin flap necrosis,
abdominal bulge, and hernia and about five times the
rate of donor-site infection.
The answer to the question "Is the free TRAM flap
an acceptable option for obese patients?" is still
not totally clear even after this study. Although the
total flap loss rate in the obese group (3.2 percent)
was higher than that in the overweight group (1.9 percent)
and in the normal-weight group (0.0 percent), well over
90 percent of patients in the obese group had successful
outcomes. It is clear that the incidence of failures
and complications is higher in obese patients, and in
fact there seems to be an almost linear relationship
between complications of all kinds and body weight.
Nevertheless, most obese patients were pleased by their
results and were happy that they had undertaken the
surgery.
Given the findings from our study, the decision whether
to perform free TRAM flap for breast reconstruction
in obese or overweight patients probably should be individualized
based on the patient's and the physician's perspective.
For those who are willing to accept higher risks of
complications, free TRAM flap may be considered an acceptable
choice for breast reconstruction, even for obese patients.
We believe that for markedly and morbidly obese patients
(body mass index >40), TRAM flap breast reconstruction
probably should be avoided if possible. For patients
who are obese but are less than markedly obese (body
mass index equal to or greater than 30 but less than
40), free TRAM flap reconstruction may be considered
for those patients in otherwise good health who are
well informed of their increased risk of failure and
complications. If the reconstruction is a delayed one
and the patient is able to reduce her risk by losing
weight before the surgery, she should be encouraged
to do so. That a patient is overweight (body, mass index
25 to 30) probably should not be considered a contraindication
for free TRAM flap breast reconstruction.
David W. Chang, M.D.
Department of Plastic and Reconstructive Surgery
University of Texas M. D. Anderson Cancer Center
1515 Holcombe Boulevard, Box 62
Houston, Texas 77030
dchang@mdaizderson.org
