Keywords
pulmonary sequestration - anatomical segmentectomy - video-assisted thoracic surgery
Introduction
Anatomical segmentectomy is an increasingly attractive alternative to lobectomy in
selected adult patients.[1]
[2] In children, however, the procedure is less common because of its technical complexity.
Segmentectomy requires dividing the segmental bronchus and pulmonary vessels at the
hilum. A history of pulmonary infection further increases the risk of complications.[3]
Here, we present the case of a successful anatomical basal segmentectomy in a child
with intralobar pulmonary sequestration (IPS) and recent pneumonia, using the invasive
hybrid video-assisted thoracic surgery (VATS) approach.[4]
Case Report
A 6-year-old girl with a history of congenital cystic lung disease was referred to
our hospital with persistent cough and fever refractory to oral antibiotic therapy.
She was diagnosed antenatally with IPS in the left lung with anomalous arterial supply
to the left basal segment ([Fig. 1]). She had no other symptoms prior to admission. Chest computed tomography (CT) showed
diffuse consolidation of the left lower lobe. A diagnosis of bacterial pneumonia was
made, and intravenous ceftriaxone was initiated. She was discharged after 5 days of
treatment.
Fig. 1 Postnatal-enhanced computed tomography showing an anomalous arterial supply from
the descending aorta to the left lower lobe.
High-resolution CT showed a cystic lesion limited to the basal segment of the left
lower lobe. The apical segment was hypertrophic, suggesting compensatory growth, with
normal arterial perfusion, normal venous drainage, and a normal bronchial connection
([Fig. 2]). A diagnosis of IPS was confirmed, and elective basal segmentectomy with a hybrid
VATS approach was planned.
Fig. 2 Preoperative high-resolution computed tomography showing the affected BS with a normal
AS. (a) UL, BS. (b) UL, AS. AS, apical segment; BS, basal segment; UL, upper lobe.
Surgery was performed under general anesthesia with selected left bronchial occlusion,
using a Fogarty catheter. The patient was placed in the right decubitus position.
A 10-mm thoracoscopic trocar was inserted through the ninth intercostal space in the
left mid-axillary line. Thoracotomy was performed through the fifth intercostal space
with a 5-cm posterolateral incision. Inflammatory adhesions between the left lung
and the chest wall were dissected under thoracoscopic vision. An aberrant artery running
through the pulmonary ligament was detected. This was divided by silk thread ligation,
clipping, and division using a bipolar system (the LigaSure vessel sealing system
(Valleylab/Tyco Healthcare) ([Fig. 3a]). The common basal vein was identified and divided posteriorly.
Fig. 3 Intraoperative view. (a) AA and (b) UL, AS, BS, BA. AA, aberrant artery; AS, apical segment; BA, basal artery; BS, basal
segment; UL, upper lobe.
Following division of the major fissure, the basal arteries were cut individually
([Fig. 3b]). Following confirmation of aeration in the apical segment, the basal bronchus was
clamped and transected with an endoscopic linear stapler. The lung parenchyma was
divided with the stapler on the inflation–deflation line between the affected basal
segment and the healthy apical segment ([Fig. 4]). The specimen was retrieved through the thoracotomy without extension of the wound.
The size of the specimen was 10 × 9 cm. The operative time was 217 minutes, and the
estimated blood loss was 56 mL.
Fig. 4 Thoracoscopic view after basal segmentectomy showing preserved healthy apical segment.
AS, apical segment; UL, upper lobe.
Histopathological examination revealed a cystically dilated bronchus with inflammation
of the surrounding parenchyma. The margin of the specimen did not include cystic lesion,
confirming complete resection of the lesion. The wall of the aberrant artery was composed
of elastic fibers. These findings were compatible with a diagnosis of IPS.
The patient recovered without complications and was discharged home on postoperative
day 5. A chest radiograph 4 months postprocedure demonstrated satisfactory expansion
of residual lung ([Fig. 5]). No respiratory impairment was reported throughout the 1-year follow-up period.
Fig. 5 Postoperative chest radiograph (a) 5 days after surgery and (b) 4 months after surgery.
Discussion
Pulmonary sequestration is a congenital lung malformation defined as nonfunctional
lung tissue without a bronchial connection to normal lung.[5] In most cases, the abnormal lung tissue is supplied through an anomalous artery,
usually arising from the descending aorta. This rare condition accounts for ∼1% of
all congenital lung malformations. There are two subtypes, characterized according
to their pleural covering: IPS, which is surrounded by the neighboring lung's pleura
and extralobar pulmonary sequestration, which has its own pleura.
Definitive treatment of IPS is surgical resection to eliminate the possibility of
recurrent respiratory infection, malignant transformation, and sudden hemoptysis caused
by a ruptured anomalous artery.[6]
Lobectomy has been the most common surgical approach to IPS, as it is technically
simple and affords reliable confirmation of complete resection. As recent advances
in radiology have enabled surgeons to understand the detailed pulmonary anatomy preoperatively,
lung-sparing surgeries such as segmentectomy and wedge resection are now considered
viable options.[3]
Anatomical segmentectomy is preferable to lobectomy as the former spares lung that
has potential for compensatory growth following lung resection. One report suggested
decreased exercise tolerance of children following lung resection.[7] In older children, we do not expect a great deal compensatory lung growth following
lung resection. Nevertheless, sparing healthy lung is valuable for preserving overall
respiratory function, particularly if the healthy lung is hypertrophic, as in our
case.[8] The preserved lung can prevent thoracic deformity by expanding into the space created
by resection.[9] Finally, defined anatomical segmentectomy decreases the risk of residual lesion
that often results from atypical resections.[3]
[10]
Another lung-sparing surgical approach is wedge resection, in which the affected lung
is nonanatomically resected at the demarcation line. In wedge resection, sufficient
space and margins are required to clamp the parenchyma with a surgical stapler. In
the present case, the lesion was too large, and there was not adequate space to staple
the parenchyma without risk of injuring hilar structures. The lesion occupied almost
the entire basal segment, making it difficult to distinguish diseased tissue from
normal parenchyma. We felt wedge resection risked leaving residual lesion. Therefore,
we opted for anatomical segmentectomy.
Anatomical segmentectomy in this case presented several challenges. First, the patient
had a history of pneumonia that might have caused severe adhesions in the thoracic
cavity. Second, unlike other congenital lung malformations, resection of an IPS necessitates
division of an anomalous artery. This requires meticulous manipulation deep in the
thoracic cavity. To solve these problems, we employed a hybrid VATS approach with
satisfactory results.
The efficacy of thoracoscopy in pediatric patients has been well documented over the
past 20 years.[11] Thoracoscopic surgery is a safe and effective procedure. The procedure decreases
postoperative pain and length of hospital stay.[12] However, the port-access feature limits the direction of view and mobility of surgical
instruments. Therefore, thoracoscopic surgery tends to be avoided in complicated cases,
such as newborns with comorbid congenital anomalies or respiratory infections.[13]
[14]
Hybrid VATS is a variation of thoracoscopic surgery in which the procedure is performed
using a combination of direct view through a utility thoracotomy and magnified view
via thoracoscopy.
Excision of an IPS entails the risk of tearing the aberrant artery and subsequent
life-threatening hemorrhage.[15] In our case, under magnification, the aberrant artery was easily distinguished from
surrounding inflammatory tissues, and meticulous division was achieved despite the
presence of a severe pneumonia.
There are reports of pediatric lung surgery employing a complete VATS approach without
the use of a utility thoracotomy.[16] In our case, a complete VATS approach might have been unsuitable, as the lesion
was too large to retrieve via a port site. We believe a 5-cm utility thoracotomy was
necessary as well, as we required meticulous dissection and separation of tissues
in a small and deep thoracic space.
There is some debate over timing of surgery for congenital pulmonary malformations,
especially regarding risk in the presence of recent pneumonia.[17] Rather than performing surgery when our patient was young and small, we adopted
a “wait-and-see” approach, and delayed surgery until the infected sequestration became
infected and was successfully treated. By this time, the patient was older and larger,
both conditions being more favorable for resection. The patient's lung had healed
from pneumonia well enough that the anatomical margin was easily distinguishable.
This made less-invasive segmentectomy more feasible. Although we found some adhesions
between the lung and the parietal pleura, these could be dissected safely under thoracoscopic
vision.
Conclusion
We safely performed an anatomical basal segmentectomy with magnified vision using
a hybrid VATS approach in a child with IPS following a severe pneumonia. Our results
suggest that the indications for hybrid VATS segmentectomy may be expanded further
to include segmental lesions in children.
