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Is the grass greener? Early results of the Nuss Pprocedure
Is the Grass Greener?
Early
Results
of the Nuss Procedure
By Scott Engum, Fred Rescorla, Karen West, Thomas Rouse, L.R. “Tres” Scherer, and Jay Grosfeld Indianapolis,
Background/Purpose: Minimal access surgery (MIS, Nuss Procedure) is gaining acceptance rapidly as the preferred method for pectus excavatum repair. This shift in operative management has followed a single institution’s evaluation of the procedure. This report describes an additional experience with the Nuss procedure. Methods:Twenty-one patients with pectus excavatum underwent repair by the Nuss Procedure. The patients ranged in age from 5 to 15 years (average, 8.2 years). There were 19 boys and 2 girls. Results: In 1 patient (age 5 years) the MIS procedure was aborted because of persistence of chest wall asymmetry. The other 20 patients had completion of their procedure without intraoperative complication. The operating times ranged from 45 to 90 minutes; however, there was an additional anesthetic set-up time (average, 45 minutes). All cases utilized a single support bar (II to 17 inches). Patients underwent extubation in the operating room and were admitted to a ward bed with an epidural catheter in place for pain control and received intravenous analgesia. The hospital stay ranged from 4 to 11 days and averaged 4.9 days. Early postoperative complications included ileus (n = I), bilateral pleural effusion (n = 2), atelectasis (n = I), fungal dermatitis (n = l),
T
HE REPAIR of pectus excavatum in childhood is a well-established procedure with a generally excellent outcome. The development of restrictive lung disease is unusual after pectus excavatum repair but may result in pulmonary symptoms that range from minor to severe. Presumably. the mechanical cause of the restrictive pulmonary disease is poor growth of the bony thorax after pectus repair combined with increased rigidity of the chest wall, which can severely limit vital capacity and air flow characteristics. There is debate in the literature regarding the best age for repair. In older children, the procedure tends to be more prolonged with increased blood loss, whereas in younger children, rib growth may
Indiana
pneumothorax (n = I), and flipped pectus bar (n = 2). Delayed complications included flipped pectus bar (n = 2). marked pectus carinatum requiring bar removal (n = I), mild carinatum (n = I), mild bar deviation (n = I), progressive chest wall asymmetry (n = 3) with 1 requiring bar removal and open pectus repair, pleural effusion (n = I), and chronic persistent pain requiring bar removal (n = I). The length of follow-up is 3 to 20 months with an average of 12.3 months. Conclusions: The Nuss Procedure is quick, minimally invasive, and a technically easy method to learn; however, our data indicate there is a significant learning curve. Although previous reports suggest that few complications occur, we believe further assessment of patient selection regarding age, presence of connective tissue disorder, and severe chest wall asymmetry are still needed. Long-term follow-up also will be required to assure both health professionals and the public that this is the procedure of choice for patients with pectus excavatum. J Pediatr Surg 35:246-251. Copyright ,cl 2000 by W.B. Saunders Company. INDEX WORDS: Pectus excavatum, minimally invasive surgery, thoracic
chest wall abnormalities.
deformities,
be impaired with resulting asphyxiating thoracic chondrodystophyl and occasionally overgrowth (hypertrophy) of the chest wall above the repair. In light of these complications, Dr Nuss raised the question as to why is it necessary to perform an extensive procedure when chest wall pliability has been seen.‘.3 Subsequent development of the minimally invasive pectus repair (Nuss procedure) helped avoid (I) an anterior chest wall incision, (2) the need to raise pectoralis muscle flaps. (3) the need to resect costal cartilage, or (4) perform a sternal osteotomy. The Nuss operation is associated with a shorter operating time with minimal blood loss and early return to full activity. The procedure also resulted in normal long-term chest strength. expansion. flexibility. elasticity. and had comparable long-term cosmetic results when compared with the traditional open pectus excavatum repair. With the Nuss operation rapidly gaining acceptance as the preferred method for pectus excavatum repair based on a single institution’s evaluation of the method, this report describes an additional experience with the Nuss procedure, and suggests that careful selection of patients, a learning curve, and modifications in the performance of this technique are important considerations. Journal
of Pediatric
Surgery,
Vol35,
No 2 (February),
2000: pp 246-251
NUSS
PROCEDURE:
EARLY
RESULTS
247
MATERIALS From
August
excavatum ranged
1997
to December
underwent
in age from
boys and 2 girls.
AND
repair
using
METHODS 1998,
21 children
the Nuss
technique.
The
8.2 years.
There
5 to I5 years and averaged
Indications
for operation
with
pectus patients were
19
were based on the severity
of
the defect. and IS of 2 I patients were symptomatic (shortness of breath on exertion. and chest pain) preoperatively. Six patients did not have any
preoperative
went
either
examinations, cardiac
testing
exercise
3 restrictive
valve
obtained
prolapse).
The
outer
Lorenz course
the pectus
support
bar rotating
patient’s steel
chest
of the chest
produced
of the chest
wall
iodophor
solution.
were
I child
that
hernia was
as a
measured
bar was selected
in the supine
with muscle
relaxation.
received an epidural block for postoperative were positioned with both arms at their
(Walter
by a blanket
bilaterally.
the patient
After
was draped
position
of
pain control. The side with a slight
under
the back
skin
preparation
with
under
The majority
sterile
to expose with
linen,
an
and the
previously selected steel bar was bent to conform to the patients chest wall to maintain a convex shape. A transverse incision 2.5 cm long was in each
lateral
chest
lines at the deepest
was raised
illustrate
of the
was performed
elevation
made
radiographs
included
diaphragmatic
length
or
FL). All patients received a B-hour (25 mg/kg) starting 30 minutes before
anesthesia
the sides
axillaty
Chest
operation
rndotracheal
patients patients
Fig 2.
diameter
pattern)
and I indicating consultations
of patients
a congenital
and the correct
The
general
the
of
group
I.5 under-
(n = 9. 5 normal
examinations
and pulmonary
This
Surgical. Jacksonville. of intravenous cefazolin
incision.
with
repair convex
preoperatively.
patient, 5 days postoperatively and a pleural effusion.
Cardiology
the remaining testing
and I obstructive
tn = 8.7 normal
when appropriate.
had a previous newborn.
whereas function
abnormalities,
echocardiogram
mitml
Fig 1. Thirteen-year-old pectus support bar flipped
performed, pulmonary
anteriorly,
(A) inferiorly,
wall
between
the anterior
level of the sternal
and the previously
and (B) superiorly,
depression.
selected
at the l-year
intercostal
follow-up
and posterior A skin tunnel space was
visits.
246
ENGUM
ET AL
. entered with 30-cm long mediastinum opposite enlarged. the tract guide the
a small Kelly clamp for initial access to the chest. Next. a curved Kelly clamp was advanced slowly across the immediately under the sternum until it emerged on the
side of the chest in the same intercostal space. The tunnel was and 2 strands of braided umbilical tape were pulled through with one of the strands remaining as a back up. the other to Kelly clamp in from the opposite side to widen the tunnel. The
carefully measured and selected steel bar was then tied to the umbilical tape and was pulled beneath the sternum with the convexity facing posteriorly. When the bar was in position, it was turned over so that the convexity faced anteriorly, thereby elevating the sternum and anterior chest wall to the desired position. The bar was then secured with multiple interrupted 0 or 2-O suture (absorbable or nonabsorbable) to the lateral chest wall muscles. Before closing the incisions. positive end expiratory pressure was added to prevent pleural air trapping and minimize multiple obtained
the risk of pneumothorax. The wounds were closed in layers with absorbable suture. and a chest radiograph was in the opemting room before transporting the patient to the
recovery room after extubation. Patients were treated in a ward bed and were maintained with intravenous sedation and pam management in a supine position for the first 2 days to prevent displacement of the steel bar. Patients were discharged from the hospital after pain control was achieved with oral analgesia medication, the patient tolerated a full diet, and were able to ambulate independently. Full activities were permitted after 30 days postoperatively. Patients underwent follow-up every 4 months postoperatively and are scheduled for anticipated bar removal at 2 years in an ambulatory surgical setting.
RESULTS
Of the 21 patients selected for the Nuss procedure. 20 completed the minimally invasive operation. One patient (age 5 years) had the procedure aborted after an attempt at the minimally invasive technique because of persistent chest wall asymmetry. The other 20 patients had completion of their procedure without intraoperative complication. The operating times ranged from 45 to 90 minutes; however, there was an additional anesthetic set-up time of approximately 45 minutes. All cases utilized a single stainless steel support bar (11 to 17 inches). Blood loss was minimal for all procedures, and no patient required transfusion. Patients underwent extubation in the operating room and were admitted to a ward bed with an epidural catheter in place and given supplemental intravenous pain management. The hospital stay ranged from 4 to 11 days and averaged 4.9 days. Early postoperative complications occurred in 8 of 20 patients and included ileus (n = l), bilateral pleural effusion (n = 2). atelectasis (n = l), fungal dermatitis (n = l), pneumothorax (n = l), and a flipped pectus bar (n = 2; Fig 1). The atelectasis resolved with time, using pulmonary toilet and incentive spirometry. The fungal dermatitis was a result of lying flat for 2 days, collection of moisture on the back, and a significant reaction to the tape used to secure the epidural catheter. Topical therapy, removal of inciting agents, and ambulation all improved this condition. Two patients required early bar repositioning because of inadequate stabilization and the use of too short a support bar. The patient with a bar of insufficient length had a
Fig 3. Thirteen-year-old patient with recurrent pectus excavatum after pectus support bar removal at 2 months postoperatively secondary to chronic pain. This photograph was taken 6 months after bar removal.
poor outcome with the bar flipping and tearing the intercostal space bilaterally resulting in bilateral pleural effusions and pneumothorax. Delayed complications included flipped pectus bar in 2, marked carinatum requiring early bar removal at 6 months in 1. mild carinatum in 1, mild bar deviation in 2 (Fig 2A and B). pleural effusion requiring thoracentesis in 1, progressive chest wall asymmetry in 3 (1 required bar removal and an open repair), and persistent pain and development of scoliosis requiring premature bar removal at 2 months in 1 (Fig 3). Both early flipped bars were repositioned in the operating room under anesthesia. The individual that had a marked carinatum defect may have a connective tissue disorder of unknown etiology. Those individuals with mild carinaturn, mild bar deviation, and progressive chest wall asymmetry have been observed periodically at this time to monitor the long-term appearance of the chest wall. One child with chest wall asymmetry required bar
NUSS
PROCEDURE:
EARLY
Fig 4.
RESULTS
Postpectus
repair
at 20 months
follow-up.
removal and an open repair because of the persistent chest wall deformity. The length of follow-up is from 3 to 20 months and averaged 12.3 months. DISCUSSION Extensive operative procedures for the repair of a pectus excavatum in young children can interfere with chest wall growth resulting in severe pulmonary dysfunction. Delaying repair until 6 to 8 years of age, and limiting the cartilage resection to short segments of 3 or 4 cartilages on each side combined with a minimal sternal osteotomy usually can prevent this complication.’ Using the traditional open pectus excavatum repair it is recommended that children not be operated on in early infancy and childhood because there are no obvious advantages to early repair, and in some instances. chest wall growth may be impaired.’ The Nuss Procedure is a quick. minimally invasive and technically easy operation to learn. Several factors are important to achieve a successful outcome and have been outlined by Nuss et al.? The pectus bar should be strong enough to support the chest in the corrected position even when the child sustains unexpected trauma. The bar
Completely
normal
chest
contour
and flexibility.
needs to be long enough to accommodate growth for 2 years. Patients with known connective tissue disorders or Marfan’s syndrome may require 2 bars to distribute the pressure of the support bar more evenly. It is absolutely essential to stabilize the bar at the initial procedure to minimize the risk of postoperative flipping. Air trapping in the thorax is of little concern and resolves with conservative treatment. The patient requires a smooth postanesthesia emergence and adequate sedation and pain control to prevent agitation and the risk of the bar flipping. An important question persists; what is the ideal age for minimally invasive chest wall repair? Dr Nuss prefers early intervention and has preformed the procedure in the 3- to 6-year age group to maximize chest wall pliability and surgical ease. However, teenagers also have been treated with this procedure and had positive results despite having a less mobile chest wall. Dr Nuss noted after puberty the chest wall was not as malleable, and initial results were not as good as in younger patients; however, the steel pectus bar resulted in a moderate degree of remodeling of the chest over the 2 years the bar
250
ENGUM
ET AL
was in place with all 3 individuals pleased with the final outcome. Although we believe this technique has certain advantages and are proponents of the Nuss Procedure (Fig 4), we raise the following concerns. First, what is the most appropriate age to perform this procedure? Patients in the 3- to 6-year age group have a large bar in place that is easily palpable on physical examination because of their slim body habitus. In addition, what is the appropriate upper age limit for this minimally invasive procedure (Fia 5A and B)? Second. when should the surgeon use a
Fig 6. Chest bar stabilizer.
Fig 5. [A) Severe pectus excavatum in a patient 15 years old before surgery. (6) Same patient at time of surgery shows desired chest wall contour and elevation.
radiograph
shows
a pectus
support
bar with
a lateral
P’ :ctus bar stabilizer to minimize the risk of the bar kipping? Third, what is considered adequate stabilization in routine patients? Fourth, is the use of a thoracoscope always necessary to minimize the risk of cardiac injury and maximize extrapleural placement? Fifth, how much chest wall asymmetry can be corrected with bar manipulation only, and should we be more selective in choosing candidates? Finally. does mild overcorrection expose the patient to a risk of carinatum deformity’? In reference to age, our philosophy has remained “what is the rush to tix the defect?” The chest wall remains reasonably pliable in the 7- to I l-years age group. and the bar size may be more accommodating to these children. The bar stabilizer issue is of concern because the developer has had a limited product supply. which indicates to us. a more wide spread use of the stabilizer than is being reported verbally. Bar stabilizers mainly have been reserved for teenage patients (Fig 6). Currently, we use multiple absorbable sutures to stabilize the bar utilizing local muscle to encase the bar and have. on occasion, placed suture around the rib itself: however, this raises concerns for delayed onset of chronic pain resulting from nerve entrapment. We have not used the thoracoscope routinely. but understand the issues raised by other surgeons who use this technique to maximize visualization. If the surgeon approaches the lateral sternal margin of the pectus excavatum on the flattened hypoplastic side. the risk of cardiac injury should be low. We
NUSS
PROCEDURE:
EARLY
RESULTS
251
currently have no upper age limit but educate the patient and their family of the desire for optimal repair and the possible necessity to convert to an open operation if the chest wall is not pliable enough to allow for appropriate elevation of the sternum. We have had 1 patient with a previous CDH repair and what appeared to be an adequate Nuss Procedure who did not achieve an optimal cosmetic result because of persistent chest wall asymmetry. This raises concerns regarding what preoperative signs and findings are important, and whether severe chest wall asymmetry may increase the risk for failure of the Nuss procedure. Finally, we initially had mildly overcorrected the repair, but now have minimized this practice because progressive carinatum developed in a few individuals. We suspect the result after bar removal for those children not overcorrected will still be adequate from a parental and patient perspective. Complications after surgical repair should be limited. With the standard open procedure, pneumothorax is infrequent; pulmonary injury with continued air leak is rare; and wound infection, hematoma, or dehiscence is limited. Hemoptysis, hemopericardium, or pericardial effusion are associated primarily with retrosternal tixation. Blood transfusions rarely are required in primary repair. but more frequently are noted in secondary repair. Because of the lack of objective postoperative measurements, series results cannot be compared. Each investigator describes less than satisfactory results in different terms. Recurrence rates reported are 28 to 16%.(’ Age at the time of operation may be a factor in recurrence. Backer et al’ found the results to be worse in patients undergoing operation at a later age, and Gilbert and Zwiret? noted that 60% of their recurrences occurred in patients over 12 years of age at the time of repair. In the current series, 14 of 21 patients (67%) had early or late postoperative complications. Although a number of these were minor (late bar deviation. pleural effusions, ileus, dermatitis. and carinatum development), 7 of 21 patients required reoperation. Four of these procedures were related to the pectus bar flipping (19%) with 1 of these individuals presenting later for bar removal. This specific patient had a bar placed that was likely too short and after
replacement with a new pectus support bar, chronic pain with significant weight loss developed allowing the bar to become loose fitting. Two patients had an open procedure after the initial Nuss procedure with 1 related to poor correction of the pectus deformity at the time of the minimally invasive procedure, and the second with late development of significant chest wall asymmetry. The last individual had a pronounced carinatum at 6 months necessitating early bar removal. After experiencing these complications we have learned a number of lessons. Bar length is of particular importance, and in the patient who experienced the bar flipping related to length, the procedure was performed just at the time longer pectus bars (15, 16, and 17 inch) and stabilizers became available, thus making the preoperative measurement vitally important to abort a procedure if appropriate bar length is not available. The 3 remaining instances of bar flipping were related to improper bar fixation and the lack of appropriate chest wall bar snugness. These individuals were treated early in the series. and we have not experienced this complication during the past year. The 2 patients that required an open procedure are concerning because both individuals seemed to be appropriate candidates for the Nuss procedure. Why I did not correct appropriately, and why the second had severe chest asymmetry is our challenge for the future. We must learn how to recognize these patients preoperatively and minimize multiple procedures and patient morbidity. We have drawn an analogy of this minimally invasive technique to that of the evolution of the laparoscopic cholecystectomy. There is an obvious learning curve. Despite the ease of the procedure and its simplistic nature, there is considerable morbidity associated with this learning curve that cannot be underestimated. Although previous reports suggest few complications occur, we believe further assessment of patient selection regarding age, presence of connective tissue disorder, and severe chest wall asymmetry are still needed. Long-term follow-up also will be required to assure both the health care professional and the public that this is the procedure of choice for patients with pectus excavatum.
REFERENCES I.
Hailer
JA Jr, Colombani
construction
after
PM.
too extensive
and
excavatum.AnnThoracSurg61:1618-1625. 2. Nuss D. Kelly RE Jr. Croitoru
Humphries too early
SL.
Cotran
RS:
et al: Chest
operations
1996 DP. et al: A IO-year
minimally invasive technique for the correction Pediatr Surg 33545552. 199X 3. Robbins
CT,
Pathologic
of pectus Basis
of
for
wall
5. Fonkalsrud
pectus
Thoracic Lange.
review
of a
excavatum.
Disease.
J
ed 2.
Philadelphia, PA. Saunders, 1979 4. Nathanson I: Chest wall abnormalities, in Loughlin GM. Eigen H teds): Respiratory disease in children: Diagnosis and management. Baltimore,
MD,
Williams
and Wilkins,
1994. pp 533-543
EW: Chest
and
Surgery.
in Bave AE ted):
Norwalk.
CT,
Glenn’s
Appleton
and
199l,pp508-514
6. PeAa A. Perez excavatum: 7. Backer chest. Acta 8. Gilbert substernal 1244,
wall deformities.
Cardiovascular
1989
L. Nurkos
S. et al: Pectus
carinatum
and pectus
Are they the same disease’? Am Surg 47:2 15-2 IS. 198 I OG, Brunner Chir JC. metal
Scan
S. Larsen
121:253-261,
Zwiren strut within
GT:
V: The surgical
treatment
of funnel
1961 Repair
a marlex
of pectus envelope.
excavatum South
using
Med J 82: 1240-
a
Early
Results
of the Nuss Procedure
By Scott Engum, Fred Rescorla, Karen West, Thomas Rouse, L.R. “Tres” Scherer, and Jay Grosfeld Indianapolis,
Background/Purpose: Minimal access surgery (MIS, Nuss Procedure) is gaining acceptance rapidly as the preferred method for pectus excavatum repair. This shift in operative management has followed a single institution’s evaluation of the procedure. This report describes an additional experience with the Nuss procedure. Methods:Twenty-one patients with pectus excavatum underwent repair by the Nuss Procedure. The patients ranged in age from 5 to 15 years (average, 8.2 years). There were 19 boys and 2 girls. Results: In 1 patient (age 5 years) the MIS procedure was aborted because of persistence of chest wall asymmetry. The other 20 patients had completion of their procedure without intraoperative complication. The operating times ranged from 45 to 90 minutes; however, there was an additional anesthetic set-up time (average, 45 minutes). All cases utilized a single support bar (II to 17 inches). Patients underwent extubation in the operating room and were admitted to a ward bed with an epidural catheter in place for pain control and received intravenous analgesia. The hospital stay ranged from 4 to 11 days and averaged 4.9 days. Early postoperative complications included ileus (n = I), bilateral pleural effusion (n = 2), atelectasis (n = I), fungal dermatitis (n = l),
T
HE REPAIR of pectus excavatum in childhood is a well-established procedure with a generally excellent outcome. The development of restrictive lung disease is unusual after pectus excavatum repair but may result in pulmonary symptoms that range from minor to severe. Presumably. the mechanical cause of the restrictive pulmonary disease is poor growth of the bony thorax after pectus repair combined with increased rigidity of the chest wall, which can severely limit vital capacity and air flow characteristics. There is debate in the literature regarding the best age for repair. In older children, the procedure tends to be more prolonged with increased blood loss, whereas in younger children, rib growth may
Indiana
pneumothorax (n = I), and flipped pectus bar (n = 2). Delayed complications included flipped pectus bar (n = 2). marked pectus carinatum requiring bar removal (n = I), mild carinatum (n = I), mild bar deviation (n = I), progressive chest wall asymmetry (n = 3) with 1 requiring bar removal and open pectus repair, pleural effusion (n = I), and chronic persistent pain requiring bar removal (n = I). The length of follow-up is 3 to 20 months with an average of 12.3 months. Conclusions: The Nuss Procedure is quick, minimally invasive, and a technically easy method to learn; however, our data indicate there is a significant learning curve. Although previous reports suggest that few complications occur, we believe further assessment of patient selection regarding age, presence of connective tissue disorder, and severe chest wall asymmetry are still needed. Long-term follow-up also will be required to assure both health professionals and the public that this is the procedure of choice for patients with pectus excavatum. J Pediatr Surg 35:246-251. Copyright ,cl 2000 by W.B. Saunders Company. INDEX WORDS: Pectus excavatum, minimally invasive surgery, thoracic
chest wall abnormalities.
deformities,
be impaired with resulting asphyxiating thoracic chondrodystophyl and occasionally overgrowth (hypertrophy) of the chest wall above the repair. In light of these complications, Dr Nuss raised the question as to why is it necessary to perform an extensive procedure when chest wall pliability has been seen.‘.3 Subsequent development of the minimally invasive pectus repair (Nuss procedure) helped avoid (I) an anterior chest wall incision, (2) the need to raise pectoralis muscle flaps. (3) the need to resect costal cartilage, or (4) perform a sternal osteotomy. The Nuss operation is associated with a shorter operating time with minimal blood loss and early return to full activity. The procedure also resulted in normal long-term chest strength. expansion. flexibility. elasticity. and had comparable long-term cosmetic results when compared with the traditional open pectus excavatum repair. With the Nuss operation rapidly gaining acceptance as the preferred method for pectus excavatum repair based on a single institution’s evaluation of the method, this report describes an additional experience with the Nuss procedure, and suggests that careful selection of patients, a learning curve, and modifications in the performance of this technique are important considerations. Journal
of Pediatric
Surgery,
Vol35,
No 2 (February),
2000: pp 246-251
NUSS
PROCEDURE:
EARLY
RESULTS
247
MATERIALS From
August
excavatum ranged
1997
to December
underwent
in age from
boys and 2 girls.
AND
repair
using
METHODS 1998,
21 children
the Nuss
technique.
The
8.2 years.
There
5 to I5 years and averaged
Indications
for operation
with
pectus patients were
19
were based on the severity
of
the defect. and IS of 2 I patients were symptomatic (shortness of breath on exertion. and chest pain) preoperatively. Six patients did not have any
preoperative
went
either
examinations, cardiac
testing
exercise
3 restrictive
valve
obtained
prolapse).
The
outer
Lorenz course
the pectus
support
bar rotating
patient’s steel
chest
of the chest
produced
of the chest
wall
iodophor
solution.
were
I child
that
hernia was
as a
measured
bar was selected
in the supine
with muscle
relaxation.
received an epidural block for postoperative were positioned with both arms at their
(Walter
by a blanket
bilaterally.
the patient
After
was draped
position
of
pain control. The side with a slight
under
the back
skin
preparation
with
under
The majority
sterile
to expose with
linen,
an
and the
previously selected steel bar was bent to conform to the patients chest wall to maintain a convex shape. A transverse incision 2.5 cm long was in each
lateral
chest
lines at the deepest
was raised
illustrate
of the
was performed
elevation
made
radiographs
included
diaphragmatic
length
or
FL). All patients received a B-hour (25 mg/kg) starting 30 minutes before
anesthesia
the sides
axillaty
Chest
operation
rndotracheal
patients patients
Fig 2.
diameter
pattern)
and I indicating consultations
of patients
a congenital
and the correct
The
general
the
of
group
I.5 under-
(n = 9. 5 normal
examinations
and pulmonary
This
Surgical. Jacksonville. of intravenous cefazolin
incision.
with
repair convex
preoperatively.
patient, 5 days postoperatively and a pleural effusion.
Cardiology
the remaining testing
and I obstructive
tn = 8.7 normal
when appropriate.
had a previous newborn.
whereas function
abnormalities,
echocardiogram
mitml
Fig 1. Thirteen-year-old pectus support bar flipped
performed, pulmonary
anteriorly,
(A) inferiorly,
wall
between
the anterior
level of the sternal
and the previously
and (B) superiorly,
depression.
selected
at the l-year
intercostal
follow-up
and posterior A skin tunnel space was
visits.
246
ENGUM
ET AL
. entered with 30-cm long mediastinum opposite enlarged. the tract guide the
a small Kelly clamp for initial access to the chest. Next. a curved Kelly clamp was advanced slowly across the immediately under the sternum until it emerged on the
side of the chest in the same intercostal space. The tunnel was and 2 strands of braided umbilical tape were pulled through with one of the strands remaining as a back up. the other to Kelly clamp in from the opposite side to widen the tunnel. The
carefully measured and selected steel bar was then tied to the umbilical tape and was pulled beneath the sternum with the convexity facing posteriorly. When the bar was in position, it was turned over so that the convexity faced anteriorly, thereby elevating the sternum and anterior chest wall to the desired position. The bar was then secured with multiple interrupted 0 or 2-O suture (absorbable or nonabsorbable) to the lateral chest wall muscles. Before closing the incisions. positive end expiratory pressure was added to prevent pleural air trapping and minimize multiple obtained
the risk of pneumothorax. The wounds were closed in layers with absorbable suture. and a chest radiograph was in the opemting room before transporting the patient to the
recovery room after extubation. Patients were treated in a ward bed and were maintained with intravenous sedation and pam management in a supine position for the first 2 days to prevent displacement of the steel bar. Patients were discharged from the hospital after pain control was achieved with oral analgesia medication, the patient tolerated a full diet, and were able to ambulate independently. Full activities were permitted after 30 days postoperatively. Patients underwent follow-up every 4 months postoperatively and are scheduled for anticipated bar removal at 2 years in an ambulatory surgical setting.
RESULTS
Of the 21 patients selected for the Nuss procedure. 20 completed the minimally invasive operation. One patient (age 5 years) had the procedure aborted after an attempt at the minimally invasive technique because of persistent chest wall asymmetry. The other 20 patients had completion of their procedure without intraoperative complication. The operating times ranged from 45 to 90 minutes; however, there was an additional anesthetic set-up time of approximately 45 minutes. All cases utilized a single stainless steel support bar (11 to 17 inches). Blood loss was minimal for all procedures, and no patient required transfusion. Patients underwent extubation in the operating room and were admitted to a ward bed with an epidural catheter in place and given supplemental intravenous pain management. The hospital stay ranged from 4 to 11 days and averaged 4.9 days. Early postoperative complications occurred in 8 of 20 patients and included ileus (n = l), bilateral pleural effusion (n = 2). atelectasis (n = l), fungal dermatitis (n = l), pneumothorax (n = l), and a flipped pectus bar (n = 2; Fig 1). The atelectasis resolved with time, using pulmonary toilet and incentive spirometry. The fungal dermatitis was a result of lying flat for 2 days, collection of moisture on the back, and a significant reaction to the tape used to secure the epidural catheter. Topical therapy, removal of inciting agents, and ambulation all improved this condition. Two patients required early bar repositioning because of inadequate stabilization and the use of too short a support bar. The patient with a bar of insufficient length had a
Fig 3. Thirteen-year-old patient with recurrent pectus excavatum after pectus support bar removal at 2 months postoperatively secondary to chronic pain. This photograph was taken 6 months after bar removal.
poor outcome with the bar flipping and tearing the intercostal space bilaterally resulting in bilateral pleural effusions and pneumothorax. Delayed complications included flipped pectus bar in 2, marked carinatum requiring early bar removal at 6 months in 1. mild carinatum in 1, mild bar deviation in 2 (Fig 2A and B). pleural effusion requiring thoracentesis in 1, progressive chest wall asymmetry in 3 (1 required bar removal and an open repair), and persistent pain and development of scoliosis requiring premature bar removal at 2 months in 1 (Fig 3). Both early flipped bars were repositioned in the operating room under anesthesia. The individual that had a marked carinatum defect may have a connective tissue disorder of unknown etiology. Those individuals with mild carinaturn, mild bar deviation, and progressive chest wall asymmetry have been observed periodically at this time to monitor the long-term appearance of the chest wall. One child with chest wall asymmetry required bar
NUSS
PROCEDURE:
EARLY
Fig 4.
RESULTS
Postpectus
repair
at 20 months
follow-up.
removal and an open repair because of the persistent chest wall deformity. The length of follow-up is from 3 to 20 months and averaged 12.3 months. DISCUSSION Extensive operative procedures for the repair of a pectus excavatum in young children can interfere with chest wall growth resulting in severe pulmonary dysfunction. Delaying repair until 6 to 8 years of age, and limiting the cartilage resection to short segments of 3 or 4 cartilages on each side combined with a minimal sternal osteotomy usually can prevent this complication.’ Using the traditional open pectus excavatum repair it is recommended that children not be operated on in early infancy and childhood because there are no obvious advantages to early repair, and in some instances. chest wall growth may be impaired.’ The Nuss Procedure is a quick. minimally invasive and technically easy operation to learn. Several factors are important to achieve a successful outcome and have been outlined by Nuss et al.? The pectus bar should be strong enough to support the chest in the corrected position even when the child sustains unexpected trauma. The bar
Completely
normal
chest
contour
and flexibility.
needs to be long enough to accommodate growth for 2 years. Patients with known connective tissue disorders or Marfan’s syndrome may require 2 bars to distribute the pressure of the support bar more evenly. It is absolutely essential to stabilize the bar at the initial procedure to minimize the risk of postoperative flipping. Air trapping in the thorax is of little concern and resolves with conservative treatment. The patient requires a smooth postanesthesia emergence and adequate sedation and pain control to prevent agitation and the risk of the bar flipping. An important question persists; what is the ideal age for minimally invasive chest wall repair? Dr Nuss prefers early intervention and has preformed the procedure in the 3- to 6-year age group to maximize chest wall pliability and surgical ease. However, teenagers also have been treated with this procedure and had positive results despite having a less mobile chest wall. Dr Nuss noted after puberty the chest wall was not as malleable, and initial results were not as good as in younger patients; however, the steel pectus bar resulted in a moderate degree of remodeling of the chest over the 2 years the bar
250
ENGUM
ET AL
was in place with all 3 individuals pleased with the final outcome. Although we believe this technique has certain advantages and are proponents of the Nuss Procedure (Fig 4), we raise the following concerns. First, what is the most appropriate age to perform this procedure? Patients in the 3- to 6-year age group have a large bar in place that is easily palpable on physical examination because of their slim body habitus. In addition, what is the appropriate upper age limit for this minimally invasive procedure (Fia 5A and B)? Second. when should the surgeon use a
Fig 6. Chest bar stabilizer.
Fig 5. [A) Severe pectus excavatum in a patient 15 years old before surgery. (6) Same patient at time of surgery shows desired chest wall contour and elevation.
radiograph
shows
a pectus
support
bar with
a lateral
P’ :ctus bar stabilizer to minimize the risk of the bar kipping? Third, what is considered adequate stabilization in routine patients? Fourth, is the use of a thoracoscope always necessary to minimize the risk of cardiac injury and maximize extrapleural placement? Fifth, how much chest wall asymmetry can be corrected with bar manipulation only, and should we be more selective in choosing candidates? Finally. does mild overcorrection expose the patient to a risk of carinatum deformity’? In reference to age, our philosophy has remained “what is the rush to tix the defect?” The chest wall remains reasonably pliable in the 7- to I l-years age group. and the bar size may be more accommodating to these children. The bar stabilizer issue is of concern because the developer has had a limited product supply. which indicates to us. a more wide spread use of the stabilizer than is being reported verbally. Bar stabilizers mainly have been reserved for teenage patients (Fig 6). Currently, we use multiple absorbable sutures to stabilize the bar utilizing local muscle to encase the bar and have. on occasion, placed suture around the rib itself: however, this raises concerns for delayed onset of chronic pain resulting from nerve entrapment. We have not used the thoracoscope routinely. but understand the issues raised by other surgeons who use this technique to maximize visualization. If the surgeon approaches the lateral sternal margin of the pectus excavatum on the flattened hypoplastic side. the risk of cardiac injury should be low. We
NUSS
PROCEDURE:
EARLY
RESULTS
251
currently have no upper age limit but educate the patient and their family of the desire for optimal repair and the possible necessity to convert to an open operation if the chest wall is not pliable enough to allow for appropriate elevation of the sternum. We have had 1 patient with a previous CDH repair and what appeared to be an adequate Nuss Procedure who did not achieve an optimal cosmetic result because of persistent chest wall asymmetry. This raises concerns regarding what preoperative signs and findings are important, and whether severe chest wall asymmetry may increase the risk for failure of the Nuss procedure. Finally, we initially had mildly overcorrected the repair, but now have minimized this practice because progressive carinatum developed in a few individuals. We suspect the result after bar removal for those children not overcorrected will still be adequate from a parental and patient perspective. Complications after surgical repair should be limited. With the standard open procedure, pneumothorax is infrequent; pulmonary injury with continued air leak is rare; and wound infection, hematoma, or dehiscence is limited. Hemoptysis, hemopericardium, or pericardial effusion are associated primarily with retrosternal tixation. Blood transfusions rarely are required in primary repair. but more frequently are noted in secondary repair. Because of the lack of objective postoperative measurements, series results cannot be compared. Each investigator describes less than satisfactory results in different terms. Recurrence rates reported are 28 to 16%.(’ Age at the time of operation may be a factor in recurrence. Backer et al’ found the results to be worse in patients undergoing operation at a later age, and Gilbert and Zwiret? noted that 60% of their recurrences occurred in patients over 12 years of age at the time of repair. In the current series, 14 of 21 patients (67%) had early or late postoperative complications. Although a number of these were minor (late bar deviation. pleural effusions, ileus, dermatitis. and carinatum development), 7 of 21 patients required reoperation. Four of these procedures were related to the pectus bar flipping (19%) with 1 of these individuals presenting later for bar removal. This specific patient had a bar placed that was likely too short and after
replacement with a new pectus support bar, chronic pain with significant weight loss developed allowing the bar to become loose fitting. Two patients had an open procedure after the initial Nuss procedure with 1 related to poor correction of the pectus deformity at the time of the minimally invasive procedure, and the second with late development of significant chest wall asymmetry. The last individual had a pronounced carinatum at 6 months necessitating early bar removal. After experiencing these complications we have learned a number of lessons. Bar length is of particular importance, and in the patient who experienced the bar flipping related to length, the procedure was performed just at the time longer pectus bars (15, 16, and 17 inch) and stabilizers became available, thus making the preoperative measurement vitally important to abort a procedure if appropriate bar length is not available. The 3 remaining instances of bar flipping were related to improper bar fixation and the lack of appropriate chest wall bar snugness. These individuals were treated early in the series. and we have not experienced this complication during the past year. The 2 patients that required an open procedure are concerning because both individuals seemed to be appropriate candidates for the Nuss procedure. Why I did not correct appropriately, and why the second had severe chest asymmetry is our challenge for the future. We must learn how to recognize these patients preoperatively and minimize multiple procedures and patient morbidity. We have drawn an analogy of this minimally invasive technique to that of the evolution of the laparoscopic cholecystectomy. There is an obvious learning curve. Despite the ease of the procedure and its simplistic nature, there is considerable morbidity associated with this learning curve that cannot be underestimated. Although previous reports suggest few complications occur, we believe further assessment of patient selection regarding age, presence of connective tissue disorder, and severe chest wall asymmetry are still needed. Long-term follow-up also will be required to assure both the health care professional and the public that this is the procedure of choice for patients with pectus excavatum.
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