 |
|
Pulmonary Atelectasis After Reconstruction With a Rectus Abdominis Free Tissue Transfer
Mark K. Wax, MD;
Eben L. Rosenthal, MD;
Rodd Takaguchi, BS;
James I. Cohen, MD, PhD;
Peter E. Andersen, MD;
Neal Futran, MD
Arch Otolaryngol Head Neck Surg. 2002;128:249-252.
ABSTRACT
| |
Background Atelectasis is one of the most common postoperative complications encountered
in head and neck surgery. Risk factors include preexisting pulmonary disease,
the procedure performed, and the length of anesthetic. Regional flaps used
to reconstruct defects in the head and neck predispose to radiographic atelectasis.
The rectus abdominis myocutaneous flap is usually transferred as a free tissue
transfer. Harvesting the flap results in abdominal wall pain and postoperative
splinting that may contribute to an increased development of atelectasis.
To our knowledge, this issue has not been previously examined.
Design Retrospective review.
Results Fifty-three patients underwent rectus abdominis myocutaneous free flap
reconstruction following major ablative procedures for head and neck cancer.
The flap size ranged from 5 x 7 to 25 x 27 cm. Most flaps were
8 x 15 cm. The cutaneous area transferred ranged from 35 to 600 cm2 (mean, 120 cm2). These patients were compared with a group
of 53 patients who were matched for age, sex, length of the procedure, and
stage of disease. Postoperative atelectasis was radiographically detected
in 37 (70%) of the patients who underwent rectus abdominis myocutaneous free
flap reconstruction vs 41 (77%) of the controls. Major atelectasis was not
encountered in any patient in either group. Patients with a larger cutaneous
paddle (>120 cm2) had a higher atelectasis score than patients
with smaller cutaneous paddles ( 120 cm2) (P = .02).
Conclusions The incidence of radiographic postoperative atelectasis in patients
undergoing rectus abdominis myocutaneous free tissue transfer is high. The
degree of atelectasis is small, and the clinical correlation and relevance
are minimal.
INTRODUCTION
ONE OF the most common postoperative complications in head and neck
oncologic surgery is pulmonary atelectasis.1
Intraoperative mechanical ventilation, combined with respiratory depression
from narcotics, contributes to pooling of pulmonary secretions.1-2
To our knowledge, the incidence of pulmonary atelectasis in patients undergoing
head and neck surgery has not been well characterized. Radiographic atelectasis
has been demonstrated in 20% to 80% of patients, with major atelectasis being
recorded in 1% to 10% of the patients.1-3
Reconstruction of head and neck oncologic ablative defects often entails transfer
of regional myocutaneous flaps. If these flaps are based on the chest wall,
then splinting to diminish incisional pain may be a contributing factor for
atelectasis. Smoking history, duration of anesthetic, age, and types of surgery
are also considered to be risk factors.4-5
Seikaly et al1 reported that a pectoralis major
myocutaneous flap may increase the frequency of postoperative pulmonary atelectasis.
In contrast, Schuller et al2 contradicted this
and found no increased incidence of clinically relevant atelectasis in their
patients undergoing pectoralis major myocutaneous flap reconstruction. Wax
and Hurst3 compared patients with latissimus
dorsi myocutaneous flaps with a control group and found a high rate of radiologic
atelectasis but no difference among the groups. Patients with large cutaneous
paddles had significantly more radiographic atelectasis than patients with
smaller cutaneous paddles. The clinical relevance was not established.
The advent of free tissue transfer has seen the pectoralis major and
pedicled latissimus dorsi myocutaneous flaps replaced by other composite tissues.
The rectus abdominis myocutaneous free flap is frequently transferred to the
head and neck as a free tissue transfer. In our practice, it is the most common
myocutaneous tissue used in head and neck reconstruction.
Mobilization and harvesting of a rectus abdominis flap entail a large
abdominal incision from the zyphoid process to the pubis. Large skin paddles
are harvested with the underlying rectus abdominis muscle. The anterior rectus
sheath is harvested to a lesser extent. Closure is accomplished primarily
with the fascia often being tight and the skin incision also being tight.
We hypothesized that the tight abdominal closure and associated abdominal
pain may lead to significant splinting and possibly to a higher incidence
of pulmonary atelectasis. We, therefore, examined our patients for the development
of atelectasis postoperatively.
PATIENTS AND METHODS
Between January 1, 1999, and December 30, 2000, 53 patients underwent
rectus abdominis myocutaneous flap reconstruction following a major ablative
procedure for head and neck malignancy. Patients were retrospectively examined.
An oncologic surgical resection was usually performed by a separate ablative
team. Reconstruction was usually started once the defect size was known. This
allowed for a 2-team approach. Twenty-six procedures were performed at Oregon
Health Sciences University, Portland, with all reconstructions being performed
by the same surgeon (M.K.W.). Twenty-seven procedures were done at the University
of Washington, Seattle, with all reconstructions being performed by the same
surgeon (N.F.). These patients were then matched to a pool of patients who
had undergone similar head and neck oncologic and reconstructive procedures.
Patients in the 2 groups were carefully matched for age, sex, site of the
flap, stage of disease, and duration of anesthetic. The control group consisted
of patients who underwent ablation and some form of reconstruction, usually
involving a radial forearm or fibula osteocutaneous free flap. Patients with
pectoralis major or latissimus dorsi myocutaneous flaps were eliminated from
the control group. No patient in either group required repositioning. The
total anesthetic time, maximum postoperative temperature in the first 24 hours,
and size and site of the rectus abdominis myocutaneous flap were recorded.
All patients with rectus abdominis myocutaneous flaps had primary fascial,
as well as cutaneous, closure. Preoperative (posterior or anterior and lateral)
and day 1 postoperative (portable) chest radiographs were reviewed by the
radiologist, who was blinded to the patients' operative procedure. The patients'
postoperative radiograph was assigned an atelectasis score based on the extent
of atelectasis according to a previously described system:
The atelectasis category of none indicated a total atelectasis score
of 0; minor, 1 to 5; and major, greater than 5. Statistical analysis of all
atelectasis scores comparing flap with control groups was performed using
the Spearman rank correlation coefficient. Comparison of atelectasis scores
between those with large and small flaps in the control group was performed
with a Mann-Whitney test. Comparisons of flap size (small, large, and control)
and atelectasis category (nonminimal and major) were performed with a  2 test. Significance was at the P= .05 level.
RESULTS
Of the 53 patients in this study group who underwent rectus abdominis
myocutaneous flap reconstruction, all flaps were transferred as free tissue.
The maximum temperature on the first postoperative day was similar in both
groups. The mean anesthetic time was longer in the control group, but not
significantly so (P = .9). All patients were smokers.
Thirty-four had tracheotomies or laryngostomies. All patients undergoing flap
reconstruction had stage III or IV disease. Previous treatment was similar
between groups. The flap surface area ranged from 35 to 600 cm2
(mean, 120 cm2) (Figure 1).
The flap size ranged from 5 x 7 to 25 x 27 cm (mean, 8 x
15 cm). This was a reflection of the size of the defects that needed to be
reconstructed. The incidence of postoperative atelectasis in the control group
was 41 (77%) of 53 patients. The corresponding figures for the flap group
were 37 (70%) of 53 patients. No major atelectasis was seen in the patients
undergoing flap reconstruction. There was no difference in the atelectasis
scores and categories between patients with rectus abdominis myocutaneous
flaps and patients in the control group (Figure 2 and Figure 3,
respectively). Arbitrarily, flaps with skin paddles greater than 120 cm2 were considered large and were analyzed separately. Patients with
large flaps demonstrated atelectasis 79% of the time compared with patients
with smaller flaps, who demonstrated atelectasis 55% of the time. When comparing
the atelectasis scores, patients with larger flaps had a significantly higher
atelectasis score than did patients with smaller flaps (P = .02). The atelectasis category was also significantly greater in
patients with larger flaps (P = .03) (Figure 4).
|
|
|
|
Figure 1. Area of the cutaneous paddle transferred
with the rectus abdominis flap.
|
|
|
|
|
|
|
Figure 2. Comparison of the radiologic atelectasis
score between control patients and patients undergoing rectus abdominis flap
reconstruction.
|
|
|
|
|
|
|
Figure 3. Comparison of radiologic atelectasis
categories between control patients and patients undergoing rectus abdominis
flap reconstruction.
|
|
|
|
|
|
|
Figure 4. Comparison of the atelectasis
score between patients with large and small rectus abdominis flaps.
|
|
|
In patients with rectus abdominis myocutaneous flaps, there was no correlation
between the side on which the flap was harvested and the side that developed
the atelectasis. The presence of radiographic preoperative pulmonary disease
could not be correlated or compared with postoperative atelectasis scores
because of the small degrees of atelectasis observed. Variables in radiographic
techniques (anterior or posterior and lateral) vs a portable film make direct
comparison difficult.
COMMENT
The pectoralis major myocutaneous flap is the workhorse in the reconstruction
of head and neck defects following ablation for head and neck cancers.1-3 Increasing use of free
tissue transfer has allowed for more accurate replacement of composite tissue
defects with like composite tissue. In cases in which large cutaneous paddles
and tissue bulk are required, myocutaneous flaps are the reconstructive option
of choice. In our institution, we have increasingly turned to the rectus abdominis
myocutaneous flap in instances that require large skin surface area and tissue
bulk.
Seikaly et al1 analyzed patients undergoing
pectoralis major myocutaneous flap reconstruction, and they demonstrated a
70% radiographic incidence of pulmonary atelectasis in patients who did not
undergo flap reconstruction. Major postoperative pulmonary atelectasis was
evident in 5% of these patients. When Seikaly and colleagues looked at patients
who had undergone pectoralis major myocutaneous flap reconstruction, they
demonstrated that 75% of these patients showed evidence of major atelectasis.
Sixty percent of patients with skin paddles larger than 40 cm2
had major atelectasis. Seikaly et al were unable to correlate clinical findings
with radiographic observation, and they attributed their high incidence of
atelectasis to the tight closure of the donor defect, which caused chest wall
constriction and splinting.
Schuller et al2 compared 66 patients
who did not undergo flap reconstruction with a group of 86 patients who underwent
pectoralis major myocutaneous flap reconstruction. They correlated atelectasis
with the same clinical atelectasis score. Of note, Schuller et al divided
their patients into those with preexisting pulmonary disease (PEPD) and those
without. They also attempted to correlate size of the flaps with atelectasis.
Most patients in their series had flaps with a surface area greater than 40
cm2 (mean, 71 cm2). These flaps were considerably larger
than those used by Seikaly et al.1 Patients
with no flaps and no PEPD developed atelectasis 43.8% of the time compared
with a 58.8% incidence in patients with PEPD. Major atelectasis developed
in 6.3% of these patients. Patients with pectoralis major myocutaneous flaps
developed atelectasis 36.6% of the time when there was no PEPD and 51.1% of
the time when there was PEPD. Of these patients, 6.7% developed major atelectasis.
Schuller et al2 were unable to demonstrate
an increased incidence of pulmonary atelectasis with pectoralis major myocutaneous
flap reconstruction; however, they found that patients with PEPD exhibited
a higher rate of pulmonary atelectasis. They also were unable to correlate
between larger flaps and pulmonary atelectasis.
Wax and Hurst3 looked at 18 patients
undergoing latissimus dorsi myocutaneous flap reconstruction. Fourteen patients
had pedicled flaps, while 4 had free tissue transfer. The mean size of the
flap was 128 cm2, with more than half of the flaps being 150 or
225 cm2. Eighty-three percent of the patients in their series showed
some sign of atelectasis, whereas 17% developed major atelectasis. Patients
with larger flaps (>120 cm2) were significantly more likely to
develop atelectasis than the control, or small paddle, group. In their study,
Wax and Hurst demonstrated that patients with or without flaps did equally
well. There was no correlation between the severity of radiologic atelectasis
and clinical morbidity.
The previously described studies1-3
prompted us to look carefully at patients who underwent rectus abdominis myocutaneous
free tissue transfer. The rectus abdominis myocutaneous flap provides substantial
soft tissue bulk and cutaneous area. Closure is easy with the lax skin of
the abdomen when compared with a pectoralis major myocutaneous flap. The ability
to close large defects is similar to that of the latissimus dorsi, although
it is our impression that the laxity of the abdominal wall provides for an
easier closure than does the back skin of a latissimus dorsi flap.3 The rectus abdominis myocutaneous flap involves closure
of the anterior rectus sheath. Because our technique uses a minimal harvest
of the anterior sheath, we were able to close the defects of all of our patients
without synthetic mesh. This often requires significant tension. The average
size of the skin paddle in our series was 120 cm2. Paddles ranged
from 35 to 600 cm2, and more than half of the flaps were 120 cm2. This compares with the mean size of the flap in the Schuller et al2 series of 71 cm2, the Seikaly et al1 series of less than 40 cm2, and the Wax
and Hurst3 latissimus dorsi series of 128 cm2. Our overall incidence of radiographically detected postoperative
atelectasis was 37 (70%) of 53 patients. No patient in our series developed
major atelectasis. Only 5 patients had an atelectasis score of 3, which was
still in the minor atelectasis range. When we compared patients with larger
flaps (>120-cm2 skin paddles), there was a significant increase
in the overall atelectasis score (79% vs 55%). However, the scores ranged
between 1 and 3, which are considered minor. The clinical significance of
this finding is questionable. Clinically, our patients with flaps and those
in the control group did equally well. There was no difference in postoperative
pneumonia, other pulmonary morbidity, or temperature. There was no correlation
between the side from which the flap was harvested and the side on which the
atelectasis developed.
The anesthetic time in our patient group was similar to that reported
by Wax and Hurst3 in their review of latissimus
dorsi myocutaneous flaps. In both instances, the average anesthetic time was
significantly longer than the times found in the studies by Seikaly et al1 and Schuller et al,2
which involved pectoralis major myocutaneous flaps. This may help explain
why a greater degree of atelectasis was present in patients undergoing rectus
abdominis or latissimus dorsi myocutaneous flap reconstruction as opposed
to pectoralis major flap reconstruction.
The severity of the patient's preoperative medical condition is an important
factor in determining the degree of radiologic pulmonary atelectasis.2, 4-5 The clinical relevance
of this radiologic atelectasis is unknown. Preexisting pulmonary disease and
chronic alcoholism were factors that contributed to major morbidity (pneumonia
and prolonged ventilation) in our patient population. The minor degree of
pulmonary atelectasis that developed in our patients postoperatively makes
comparison and attempted analysis of the contribution of PEPD to the morbidity
difficult. A larger prospective analysis with a comparable radiographic technique
would be important. We would expect that PEPD had a more significant contribution
to the development of postoperative pulmonary complications, as demonstrated
by Schuller et al.2
In conclusion, the rectus abdominis myocutaneous flap provides large
cutaneous and myogenous components for reconstruction of head and neck defects.
A high incidence of radiologic atelectasis is evident postoperatively in these
patients. The radiologic severity correlates with the size of the skin paddle
used. The outcome is not related to the radiologic appearance. Pulmonary complications
in this group are similar to those in patients undergoing other reconstructive
modalities.
AUTHOR INFORMATION
Accepted for publication August 16, 2001.
This study was presented at the annual meeting of the American Head
and Neck Society, Palm Desert, Calif, May 16, 2001.
Corresponding author: Mark K. Wax, MD, Department of Otolaryngology/Head
and Neck Surgery, Oregon Health Sciences University, 3181 SW Sam Jackson Park
Rd, Mail Code PV-01, Portland, OR 97201 (e-mail: waxm{at}ohsu.edu).
From the Departments of Otolaryngology/Head and Neck Surgery, Oregon
Health Sciences University, Portland (Drs Wax, Rosenthal, Cohen, and Andersen
and Mr Takaguchi), and the University of Washington, Seattle (Dr Futran).
REFERENCES
| |
1. Seikaly H, Kuzon WM Jr, Gullane PF, Herman SJ. Pulmonary atelectasis after reconstruction with pectoralis major flaps. Arch Otolaryngol Head Neck Surg. 1990;116:575-577.
FREE FULL TEXT
2. Schuller DE, Daniels RL, King M, Houser S. Analysis of frequency of pulmonary atelectasis in patients undergoing
pectoralis major musculocutaneous flap reconstruction. Head Neck. 1994;16:25-29.
FULL TEXT
|
WEB OF SCIENCE
| PUBMED
3. Wax MK, Hurst J. Pulmonary atelectasis after reconstruction with a latissimus dorsi
myocutaneous flap. Laryngoscope. 1996;106:268-272.
FULL TEXT
|
WEB OF SCIENCE
| PUBMED
4. Rigg JRA. Pulmonary atelectasis after anesthesia: pathophysiology and management. Can Anaesth Soc J. 1981;28:305-313.
WEB OF SCIENCE
| PUBMED
5. Rao MK, Reilley TE, Schuller DE, Young DC. Analysis of risk factors for postoperative pulmonary complications
in head and neck surgery. Laryngoscope. 1992;102:45-57.
WEB OF SCIENCE
| PUBMED
 CiteULike  Connotea  Del.icio.us  Digg  Reddit  Technorati  Twitter
What's this?
RELATED ARTICLE
Archives of Otolaryngology–Head & Neck Surgery Reader's Choice: Continuing Medical Education
Arch Otolaryngol Head Neck Surg. 2002;128(3):332-334.
FULL TEXT
|
