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264 Bronchoplastic procedures
https://t.me/med1917
Left-sided resections
LEFT UPPER LOBE SLEEVE RESECTION
Proximal arterial control is obtained with care to avoid
8
injury to the short apical segmental branch of the left
pulmonary artery. An umbilical tape is passed around the
proximal pulmonary artery and secured with a Rumel tourniquet. The tourniquet is not tightened unless proximal arterial
control is needed. We continue our dissection along the plane
of the artery and identify the superior segmental branch to
the lower lobe. At this point we complete the posterior fissure
with a linear stapler. The anterior segmental artery is ligated
and divided. The lingular branches of the pulmonary artery
are identified, ligated, and divided. The lung is retracted posteriorly, and the upper lobe venous drainage is divided with a
vascular stapler. The anterior portion of the fissure is completed with a linear stapler. The only remaining attachment to
the specimen is the bronchus. Two 2.0 silk stay sutures are
placed in the proximal left mainstem and used for retraction.
The airway is divided with a fresh number 15 blade proximal
and distal to the left upper lobe take off. These cuts should be
perpendicular to the longitudinal axis of the airway. The margins are inked and a frozen section examination performed.
Once the margins are confirmed to be microscopically negative, the reconstruction is begun. We use either a running or
interrupted technique as described above for the right upper
lobe sleeve.
Because the left mainstem is long, extensive proximal
resections can be performed. This situation can create a technically challenging anastomosis because proximal exposure is
obscured by the aortic arch. If required, the arch can be mobilized and carefully retracted to provide additional exposure.
As greater amounts of proximal airway are removed,
increased tension on the anastomosis can become a problem.
Usually, the tension is relieved by simply incising the inferior
pulmonary ligament. If additional release is required, the
pericardium can be incised in a U-shaped manner beneath
the inferior pulmonary vein to effect an infrahilar pericardial
release.
Proximal
bronchial
line of
division
Tumor
Superior
segmental
bronchus
LUL
Lingular
bronchus
Distal
bronchial
line of
division
Lower lobe bronchus
Left main bronchus
Superior
segmental
bronchus
Suture line
Lower lobe bronchus
8
LEFT LOWER LOBECTOMY SLEEVE RESECTION
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Outcome 265
For lesions involving the left lower lobe orifice without
9
extension into the upper lobe orifice, a lower lobectomy
with sleeve of the left upper lobe bronchus can be performed.
The arterial and venous connections to the lower lobe are
divided, and the fissures are completed. We dissect out and
pass an umbilical tape around the left mainstem and left
upper lobe bronchus. Two 0 silk stay sutures are placed in the
mainstem and used for retraction. The left upper lobe
bronchus is divided first with a fresh number 15 blade. It is
important for the division to be perpendicular to the long axis
of the airway. Next, the mainstem is divided proximal to the
extent of the tumor. The specimen is removed from the field,
and frozen section examination of the airway margins is performed. Once the margins are confirmed to be microscopically negative, the reconstruction is completed.
The anastomosis can be performed in an interrupted or
running fashion as described above for the right upper lobe
sleeve resection. Often, a large size discrepancy exists between
upper lobe bronchus and the mainstem. This situation
requires precise placement of sutures so that the discrepancy
is distributed over the entire circumference of the anastomosis.
Proximal
bronchial
line of division
Left main bronchus
LUL
Lingular
bronchus
Distal
bronchial
line of division
Left main bronchus
Suture line
LUL
Lingular bronchus
POSTOPERATIVE CARE
Following sleeve resection, the patient is extubated in the
operating room. Postoperative pain relief is guaranteed by a
functioning thoracic epidural. We utilize patient-controlled
epidurals which provide a basal as well as demand epidural
dose. Pain control is re-evaluated every shift by the nursing
staff and adjusted by the anesthesia pain service. The epidural
remains in place until the chest tubes are removed. Atelectasis
and subsequent pneumonia in the lung distal to the anastomosis must be avoided. This goal is accomplished by good
pain relief and aggressive pulmonary toilet. We start incentive
spirometry as soon as the patient is awake and begin ambulation on postoperative day 1. The chest tube remains in place
until no air leak exists, and the drainage is less than
200 ml/day. This situation usually occurs by postoperative
day 5. The epidural is capped 12 hours after the chest tube is
removed, and oral narcotics are started. If adequate pain
relief is obtained on an oral regimen, the epidural is removed.
Awake flexible bronchoscopy is performed prior to discharge
to inspect the anastomosis.
9
OUTCOME
Major complications following sleeve resection include: anastomotic dehiscence, empyema, and bronchovascular fistula.
Fortunately, the incidence of these complications is low. We
maintain a low threshold for bronchoscopy in the postoperative
period. Persistent or evolving atelectasis in the lung distal to the
bronchial anastomosis mandates bronchoscopy. A small partial
anastomotic dehiscence (<30%) with a good pericardial fat wrap
and no bronchopleural fistula can be treated conservatively. A
complete dehiscence is caused by anastomotic tension. This
problem requires reoperation and usually a completion pneumonectomy. An empyema can occur with or without a bronchopleural fistula. When it occurs without a bronchopleural
fistula, an empyema is handled with drainage, antibiotics, and
ablation of any residual space with muscle transposition. In this
case it is related to preoperative pneumonia and soilage of a
reisidual pleural space during the operation. When empyema
occurs with a bronchopleural fistula from the anastomosis, a
completion pneumonectomy is required, and management of
the infected pneumonectomy space is problematic.
266 Bronchoplastic procedures
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Bronchovascular fistula may present with massive hemoptysis. This complication occurs when an anastomotic breakdown occurs with peribronchial abscess formation which
invades into the adjacent pulmonary artery. Under these circumstances, completion pneumonectomy is performed. As
expected, the mortality of this complication is very high.
The mortality rate for sleeve lobectomy should be equivalent to lobectomy alone (3–5%). The most frequent respiratory complication is pneumonia which can be avoided by
aggressive postoperative pulmonary toilet and adequate pain
control. Local recurrence rates following bronchoplastic procedures are low (<5%) as long as the resection margins are
free of disease. This situation illustrates the importance of
frozen section examination of the bronchial margins prior to
completing the airway anastomosis. Late strictures occasionally occur and are related either to ischemia or a healed partial anastomotic dehiscence. Strictures can be handled with
dilation and silastic bronchial stent placement.
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Resection of posterior mediastinal masses
JOSEPH B. SHRAGER MD
Associate Professor of Surgery; Chief, Thoracic Surgery, Hospital of the University of Pennsylvania and Pennsylvania Hospital, University of
Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
The vast majority of posterior mediastinal masses in adults
are benign tumors or cysts. The solid masses among these
most frequently represent slow-growing neurogenic tumors
such as schwannomas (neurilemmomas), neurofibromas, or
ganglioneuromas, and less frequently leiomyomata of the
esophagus. The cysts generally represent congenital bronchogenic or esophageal duplication cysts. Certainly,
esophageal carcinoma, esophageal diverticulum, diaphragmatic hernia, and descending aortic aneurysm must always be
considered, but these lesions are commonly suggested by
Radiographs generally demonstrate a smoothly mar-
1
ginated cystic or solid mass which is quite characteristic.
The CT demonstrates the classic appearance of a posterior
mediastinal schwannoma in the costovertebral sulcus.
standard radiological studies (contrast esophagogram, computed tomography (CT)), and one is typically left with a differential diagnosis including the various benign, neoplastic,
or congenital processes listed above.
Often, these masses present as asymptomatic radiographic
abnormalities on a study obtained for unrelated reasons.
Respiratory symptoms, dysphagia, chest pain, or symptoms
related to cyst infection, however, do occur in some patients
– usually those with larger masses and more often in children
than in adults.
1
268 Resection of posterior mediastinal masses
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PRINCIPLES AND JUSTIFICATION
Because of the almost uniformly benign nature of these
masses, surgical treatment has evolved rapidly in the past
decade from an approach mandating traditional thoracotomy to one in which video-assisted thoracoscopic (VATS)
approaches have become equally acceptable if not preferable.
Certainly, VATS approaches, which have been demonstrated
to result in reduced pain and more rapid functional recovery
versus thoracotomy, find their most appropriate application
in benign diseases such as these. By either approach – VATS
or thoracotomy – exactly the same operation is performed.
The goal is complete resection, and this can almost always be
achieved. However, the potential negative consequences of a
grossly complete, but perhaps microscopically incomplete,
resection are minimal when dealing with many of these posterior mediastinal tumors, thus rendering the VATS
approach ideal for these entities.
In addition, controversy continues to exist as to whether
many of these masses require resection at all. A number of
studies have addressed the issue of whether the incidence of
an asymptomatic posterior mediastinal cyst progressing to
symptoms is sufficiently high to merit its resection at an
asymptomatic stage, and whether a measurable incidence of
malignant degeneration exists in the benign neurogenic
tumors. Although these studies have reached conflicting conclusions, it is fair to say that most thoracic surgeons, including the author, feel that these lesions should be resected upon
discovery in most patients. This aggressive approach is rendered more palatable by the availability of VATS excision. It
is reasonable, however, to follow small, asymptomatic lesions
in the elderly or those with significant comorbidities.
The VATS approach is, in the author’s practice, offered for
solid masses or cysts that are relatively small, usually asymptomatic, without signs of invasion of surrounding structures
on CT, and occurring in patients without prior surgery in that
hemithorax or another reason to suspect that major adhesions
may be present. This description would include most posterior mediastinal masses in adults. For patients who present
with infected cysts, which create a surrounding inflammatory
process obscuring normal tissue planes, or signs of invasion,
thoracotomy is most prudent. Similarly, large masses (over
5–6 cm) are also best approached by thoracotomy because
they too are likely to be more difficult to dissect safely from
surrounding structures and may be difficult to remove via
small VATS port sites. Although a number of different techniques have been described for combined anterior/posterior
bell tumors”), these also are amenable to having the anterior
portion of the operation performed by VATS in most cases.
For suspected esophageal duplication cysts, in the rare event
that any suggestion of a communication exists between the
native and cyst lumens (demonstration of fistula on esophagogram or air within the cyst), the author favors thoracotomy
to facilitate perfect mucosal repair. Otherwise, duplication
cysts may be resected by VATS.
Major morbidity and mortality are rare after these procedures. The entities most likely to lead to significant complications are the esophageal duplication cysts, resection of which
are associated with a small but real risk of postoperative
esophageal leak, and the “dumbbell” tumors, where one must
discuss preoperatively with the patient the occasional occurrence of cerebrospinal fluid (CSF) leak into the pleural space.
Additionally, if great care is not taken during resection of any
tumor that encroaches upon the neural foramen, hematoma
within the spinal canal with cord compression may occur.
The small risk of prolonged incisional pain following VATS
or thoracotomy must also be discussed with the patient, as
before any thoracic procedure. Since the intercostal nerve is
commonly resected along with neurogenic tumors, the
patient should be told to expect an area of numbness in the
associated dermatome following these procedures. Resection
of tumors associated with the upper thoracic vertebrae at the
apex of the chest may require resection of the stellate ganglion, resulting in Horner’s syndrome; and if these tumors are
on the right side, recurrent laryngeal nerve injury is also a
possibility that is rare but should be mentioned. Finally, every
patient who undergoes a VATS approach to one of these
lesions must understand and consent to the possibility of a
thoracotomy if it becomes necessary.
PREOPERATIVE ASSESSMENT AND
PREPARATION
Although preoperative studies often suggest that one is dealing with one of the benign posterior mediastinal processes
listed above, it is neither necessary nor simple to differentiate
among the various cystic or solid lesions preoperatively. A
needle biopsy of a discrete, posterior mediastinal mass with
smooth margins is unnecessary and unlikely to provide any
useful information. After CT delineates whether the mass is
cystic or solid, certain features may, however, dictate additional studies.
A cystic mass that abuts the esophagus should be evaluated
for a communication with the esophagus, as the presence of
such a communication suggests the need for thoracotomy
rather than VATS (see above). This situation can be ruled out
by preoperative barium esophagogram and confirmed by
esophagoscopy performed by the surgeon immediately prior
to surgery. Although leiomyomata have a fairly characteristic
CT appearance, a solid mass in association with the esophagus should also prompt preoperative esophagoscopy to confirm that normal mucosa overlies the mass and that it may
not, in fact, represent an esophageal malignancy. Endoscopic
ultrasound (EUS) can provide the strongest evidence short of
excision that one is dealing with a leiomyoma, and EUS may
also be useful in the occasional case where cyst fluid is of sufficiently high density that the cystic versus solid nature of a
mass is in doubt.
A solid mass in the costovertebral sulcus must be evaluated
carefully for invasion of the neural foramen. A magnetic res-
Operation 269
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onance imaging (MRI) study should be performed if it is not
entirely clear by CT that the foramen is clear. Identification of
foramenal invasion is critical and should be identified preoperatively for appropriate planning of a combined anteriorposterior approach. Patients with solid masses and a history
of hypertension should have serum catecholamine levels and
24-hour urine levels of homovanillic acid and vanillylmandelic acid determined given the rare occurrence of functional
pheochromocytomas in this location.
ANESTHESIA
Since more manipulation at the port sites is performed during these operations than during simpler VATS procedures
such as lung biopsy, epidural catheters for postoperative analgesia should be placed in these patients regardless of whether
a VATS or a thoracotomy approach is planned. General anesthesia is provided through a double-lumen endotracheal tube
with the distal cuff in the left mainstem bronchus, allowing
reliable, complete collapse of the lung in the hemithorax of
interest. The patient is placed in a full, lateral decubitus thoracotomy position. Of particular importance for these cases,
the patient should be securely held in this position. This positioning allows the operating table to be tilted as far as 45
degrees to either side without any risk of patient slippage.
Tilting in this way often allows the lung to fall sufficiently
away from the mediastinum by virtue of gravity alone, so that
an additional port site for passage of a lung retractor is not
necessary.
OPERATION
Figures 2–6 illustrate the resection of a benign neurogenic
tumor of the costovertebral sulcus. The arrangement of incisions for resection of all posterior mediastinal masses is similar but, of course, must be varied slightly depending on the
craniad-caudad level of the tumor. For resection of bronchogenic cysts of the posterior mediastinum, the procedure is
essentially identical to that described for neurogenic tumors,
with the exception of a few technical details described in the
text following Figure 6. Technical details that are different for
esophageal-associated posterior mediastinal masses such as
duplication cysts and leiomyomata are demonstrated in
Figures 7 and 8.
Skin incision placement
The author has found the illustrated placement of
2–3 cm port incisions to be optimal for the resection of
2
most posterior mediastinal masses. If the camera port is
placed much more anteriorly than the midaxillary line, the
view of the mass is often obscured by the lung despite rotation of the operating table anteriorly. If one does place the
port more anteriorly, a fourth port site for a lung retractor
may become necessary, and this maneuver only creates an
additional chance for intercostal nerve injury and increased
postoperative pain. A 0 degree telescope is preferred, but this
decision is purely surgeon’s preference, and a 30 degree telescope may be equally effective.
Sponge stick
Camera
Scissor/cautery
2
270 Resection of posterior mediastinal masses
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The two working ports are placed at approximately the
posterior–axillary line, as far craniad and caudad as possible,
and approximately equidistant from the mass on this axis.
The main working instruments are an endoscopic scissorscautery, a ring clamp used both with and without a gauze
sponge-ball (“sponge-stick”), an endoscopic peanut dissector, a long right-angle clamp, and an endoscopic clip applier.
Pleural incision
Initial exposure involves circumferentially incising the
3
pleura overlying the tumor. The pleura is incised with a
margin of about 2 cm around the tumor in all directions.
Gentle traction on the mass can be established with the
sponge-stick, which stretches the pleura sufficiently to allow
safe initial incision with the cautery scissors in the most accessible area.
3
Extension of pleural incision
As one proceeds circumferentially around the tumor, the
4
pleura is easily tented up on a standard right-angle clamp
to separate it from underlying critical structures. This separation allows one to use the cautery while incising, without fear
of damage to structures such as the esophagus and azygos.
Since the pleura can sometimes be somewhat vascular, it is
advantageous to use the cautery in this manner.
4
Further mobilization from attachments
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Once the pleura has been incised circumferentially, soft
5
tissue attachments with differing degrees of vascularity
and density must now be mobilized off of the mass. Much of
this portion of the dissection can be done bluntly, using the
sponge-stick, or, more often, as pictured here, the peanut dissector. Bands of tissue that are more vascular in appearance
are clipped or cauterized, taking care to stay away from the
azygous vein, esophagus, and vagus nerve.
Operation 271
5
The degree of traction one exerts on the tumor becomes an
important issue as the dissection proceeds towards the nerve
(usually an intercostal) to which the tumor is attached. A certain amount of gentle traction is necessary to provide
counter-tension to allow the blunt dissection to proceed. On
the other hand, overly zealous traction can result in tearing of
vascular structures and/or the nerve root at the neural foramen. The latter may result in a CSF leak, while the former
may result in the disastrous complication of intraspinal
hematoma with possible cord compression.
The author exerts this gentle traction by one of several
means. In most cases, simply pulling on the tumor gently
with the sponge-stick, as shown here, is sufficient.
Sometimes, the pleural covering which has been incised is
sufficiently adherent to the mass that this pleural overlay itself
can be grasped and manipulated to provide traction. For
smaller tumors, the mass itself can be completely encompassed in the jaws of the ring-clamp as the base is approached,
allowing the desired level of traction to be created.
The intercostal bundle lateral to the tumor is mobilized,
6
doubly clipped, and ligated lateral to the tumor (not
shown) after the other soft tissue attachments have been
taken down. This maneuver leaves the nerve root and associated vessels emerging from the neural foramen as the only
remaining attachment, as shown here. These structures are
now similarly doubly clipped, and the specimen is completely
free and may be removed. Care is taken again, at this step, not
to exert too much tension on the nerve root as these clips are
applied, for fear of causing a CSF leak or paraspinal
hematoma. The tumor is placed in an endoscopic bag for
removal through the anterior-most port site (where the intercostal space is naturally widest). A 24 French chest tube is left
in place.
6
272 Resection of posterior mediastinal masses
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If the tumor arises from the sympathetic chain, the intercostal bundles can generally be spared and the sympathetic
chain clipped and divided above and below the mass in the
final step of freeing it.
If at any time during the VATS procedure described above,
unexpected pleural studding or pleural effusion, or invasion
of the spine, head of rib, or esophagus is identified, these findings suggest that the tumor is malignant, and conversion to
thoracotomy is appropriate. Similarly, any concern about
incompleteness of resection or, certainly, safety, should result
in immediate conversion to thoracotomy.
In the case of tumors identified as “dumbbell” tumors preoperatively, the operation should be performed by a combined posterior neurosurgical and anterior thoracic
approach. A detailed description of the neurosurgical component of this procedure is beyond the scope of this chapter, but
involves laminectomy and intervertebral foraminotomy performed with the patient in a prone position. The patient is
subsequently repositioned, and the VATS procedure is carried out exactly as described above. In the rare case that unexpected invasion of the neural foramen is identified while
performing attempted primary VATS excision, one should
consult intraoperatively with a neurosurgeon. If possible, the
patient should be repositioned for an immediate posterior
approach by the neurosurgeon, followed by completion of
the resection by VATS.
If after resection of a tumor approaching the foramen one
finds persistent oozing of blood from this area, one should
never pack hemostatic agents into the area. This maneuver
may block the path of egress of blood from the spinal canal
and create a closed space in which a disastrous spinal
hematoma may form. If oozing at the foramen does not stop
with careful use of bipolar cautery at the bony margins of the
foramen or watchful waiting with temporary use of a collagen
hemostatic agent, then neurosurgical consultation should be
obtained.
Resection of neurogenic tumors arising from the posterior
mediastinum at the apex of the chest poses more complex
challenges than those at lower levels, and in most cases a
VATS approach to these tumors is inappropriate.
Bronchogenic cysts also occur not infrequently near the costovertebral sulcus. For these, the dissection is essentially the
same as for the neurogenic tumors illustrated above. The
author has found that it is helpful to dissect these, initially, with
the cyst intact. Once one has gone as far as possible in this
manner, the cyst is drained by needle aspiration. This fluid is
sent for culture and cytological examination. The deepest
recesses of the cyst cavity can be seen from within the cyst if it
is subsequently opened widely. This step generally allows the
final stages of dissection and resection. If a small portion of the
cyst wall is densely adherent to a critical structure, it may be left
in place and cauterized. If a large portion of the cyst is adherent
and is difficult to safely dissect at VATS, thoracotomy should
be performed. Figures 7 and 8 illustrate the approach to esoph-
agus-associated posterior mediastinal masses such as leiomyomata and duplication cysts (a leiomyoma is pictured).
Although the procedure is very similar in most respects
7
to that described above for the more posteriorly located
masses in the costovertebral sulcus, a few differences bear discussion. These masses are located beneath the longitudinal
muscle of the esophageal wall, but depending upon the size of
the tumor, this muscle may be so thinned out that its normal,
striated texture is hard to identify. The first step after incising
the pleura, then, is to incise this muscle layer directly over the
mass and to extend this incision approximately 1 cm proximal and distal to the mass. As shown here, this step is often
best accomplished with a blunt, right angle clamp used to
carefully dissect the muscularis off of the underlying
esophageal mucosa. The muscle is then tented up off of the
mucosa and divided.
It should be noted that if a mass is associated with a portion
of the esophagus that is obscured by the azygous arch, this
vessel can be easily sacrificed to improve exposure. This step
is accomplished with an endoscopic gastrointestinal anastomosis (GIA) stapling device with a vascular cartridge.
7
After bluntly dissecting the tumor from surrounding
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adhesions as described in Figure 5, one eventually
8
reaches the critical plane where the tumor meets the mucosa
directly. Leiomyomata usually are not densely adherent to the
mucosa, and with patience this plane can almost always be
bluntly dissected completely with the endoscopic peanut
while exerting gentle traction on the mass. This dissection can
be facilitated by introducing an endoscope from above and
transilluminating the mucosa, allowing clearer identification
of the interface between mucosa and mass.
Operation 273
8
In contrast to leiomyomata, the author has found that
duplication cysts are often so densely adherent in this plane
with the mucosa that it is impossible to safely separate the
deep wall of the cyst from the mucosa (in fact, the two may
share a common wall). Two options are available in this circumstance. One option is conversion to a thoracotomy for
incision and precise repair of the mucosa, leaving no doubt
that one has achieved complete excision of the cyst wall. The
author has generally chosen the second option, which is leaving up to 25% of the cyst wall intact against the esophageal
mucosa and gently cauterizing the epithelial lining of the
residual cyst.
Once the tumor or cyst has been removed, the
esophageal mucosa is tested for integrity by insufflating
9
air via the endoscope with the area of dissection submerged in
saline while simultaneously occluding the distal esophageal
lumen with a sponge-stick. Any mucosal leak would be identified as a stream of bubbles emanating from the area of
exposed mucosa. A leak identified at this point mandates precise suture closure, which may be done endoscopically by a
surgeon experienced in endoscopic suturing or, more likely,
by conversion to thoracotomy. The author has not found it
necessary to reclose the muscularis of the esophagus,
although this goal could certainly be achieved via VATS if felt
to be necessary.
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