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CHAPTER 19 Diaphragmatic Eventration
and Paralysis
Li Guang Hu, Liu Wei, and Jean Deslauriers
Diaphragmatic eventration (Box 19-1) is an anomaly that can be
defined as a permanent elevation of part or of an entire
hemidiaphragm without loss in the continuity in the
pleuroperitoneal layers. It is characterized by normal peripheral
muscular insertions of the diaphragm but marked decrease in
muscular fibers in the eventrated part, which has the appearance of
a thin, trans-lucent membrane. It is generally thought that
diaphragmatic eventration is a congenital anomaly resulting from an
incomplete migration of myoblasts during the fourth week of
embryologic development. It has a marked left-sided predominance
and does not generally result in para-doxical diaphragmatic
motion.
Diaphragmatic paralysis is usually an acquired disorder in which
the diaphragm, even if somewhat atrophic, is still muscular. It may
manifest in childhood or adulthood and can be associated with
phrenic nerve involvement. In many cases, especially in the adult,
the exact cause of diaphragmatic paralysis will remain unexplained
despite extensive investigation and follow-up.
Diaphragmatic herniation, with or without a hernia sac, involves
the loss of continuity in one or more of the layers constituting
the diaphragm.
Step 1. Surgical Anatomy
The mature diaphragm is a dome-shaped muscle that is anchored to
the bony structures of the thorax and is considered the most
important inspiratory muscle. When it contracts, the dome moves
inferiorly and becomes flattened, thus decreasing the intrathoracic
pressure and allowing air to be taken into the lungs. The muscular
parts that originate from the lower six ribs bilaterally, the
posterior aspect of the xiphoid, and the external and internal
arcuate liga-ments unite at the central tendon. As such, the
diaphragm should be viewed as a single muscular unit with two
halves.
The diaphragm receives its motor supply through the phrenic
nerves, which are formed at the lateral border of the anterior
scalenus muscles, chiefly from the C4 nerve roots but with
contributions from the C3 and C5 nerve roots. From there, the
phrenic nerves enter the superior mediastinum between the
ipsilateral subclavian artery and innominate vein and pass anterior
to the pulmonary hilum along the pericardium. It is at that level
that they are most susceptible to surgical injury, which may result
in complete paralysis and eventual muscular
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Chapter 19 Diaphragmatic Eventration and Paralysis 201
atrophy of the corresponding half of the diaphragm. The right
phrenic nerve reaches the diaphragm lateral to the inferior vena
cava, and the left phrenic nerve joins the diaphragm lateral to the
left border of the heart. They both divide into several terminal
branches whose anatomy delineates safe areas in the diaphragm where
incisions can be made without creating loss of diaphragmatic
function.
Arterial supply to the diaphragm is through the
pericardiophrenic and intercostal arteries; venous drainage is
through the right and left inferior phrenic veins, which drain
medially into the inferior vena cava.
BOX 19-1. Terminology
EventrationCongenital in originCan be total or partial
(anterior, posterolateral, medial)Characterized by normal muscular
insertions and thin membranous abnormal eventrated area
Predominantly left-sidedParalysisNearly always
acquiredCharacterized by atrophic muscleCan occur with or without
phrenic nerve involvementHerniaInvolves loss of continuity of one
or more of the layers constituting the diaphragm
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202 Section II Thoracic Benign
Step 2. Preoperative Considerations
In the adult population, symptoms related to an elevated
diaphragm are predominantly respiratory, mainly dyspnea, cough, and
retrosternal discomfort. The diagnosis can usually be made on
standard posteroanterior chest films (Fig. 19-1A) which show a
diaphragm in higher position than normal, forming a round, unbroken
line arching from the mediastinum to the costal arch laterally.
Often the mediastinum will be shifted toward the unaffected side.
If there is diaphragmatic paralysis, paradoxical motion can be
observed on fluoroscopic examination. Although seldom done,
diagnostic pneumoperitoneum might be useful to dis-tinguish between
an elevated diaphragm and frank herniation (see Fig. 19-1B).
Computed tomography (CT) scanning and ultrasonography are not
particularly helpful in differentiating between an elevated
diaphragm and true herniation, but magnetic resonance imaging (MRI)
allows one to acquire high-quality images in several planes, which
provides a better evalua-tion of the entire diaphragm.
The most important preoperative considerations (Box 19-2) in
patients with an elevated hemidiaphragm are to rule out a
diaphragmatic hernia or thoracic (pulmonary or mediastinal)
malignancy affecting the phrenic nerve, to document by pulmonary
function studies and exercise testing the respiratory consequences
of the elevated diaphragm, and finally to estab-lish clearly the
indication for surgery. This should be done with the understanding
that most cases of eventration diagnosed in adults should be
treated conservatively unless severe dyspnea that interferes with
normal activities, orthopnea, or gastrointestinal symptoms are
clearly related to the high position of the diaphragm. Indications
for surgery in adults are thus uncommon, and the surgeon must be
cautious before recommending plication for respiratory or digestive
symptoms thought to be secondary to an elevation of the
diaphragm.
Step 3. Operative Steps
The objective of the procedure of diaphragmatic plication is to
immobilize the diaphragm in a lower, relatively flat position (see
Fig. 19-1C) to reduce lung and mediastinal compression. This can be
done through an open posterolateral approach, video-assisted
techniques, or a laparoscopic abdominal approach. For all these
procedures, gastric decompression with a nasogastric tube is
mandatory.
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Chapter 19 Diaphragmatic Eventration and Paralysis 203
BOX 19-2. Important Preoperative Considerations in Patients with
Diaphragmatic Eventration and Paralysis
Rule out a diaphragmatic herniaRule out a thoracic malignancy
affecting the phrenic nerveDocument the respiratory consequences of
the elevated diaphragmEstablish a clear indication for surgical
repair
Figure 19-1
A B C
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204 Section II Thoracic Benign
1. Open Posterolateral Approach
The operation is carried out through a seventh interspace
posterolateral thoracotomy. The lung and mediastinum are first
examined to rule out unsuspected pathological processes, and the
diaphragm is then plicated in successive layers until it becomes
taut. This should be done with heavy interrupted silk sutures often
reinforced with Teflon pledgets to prevent tearing. The direction
of the plication is determined by the axis of the eventration,
which is generally transverse rather than anteroposterior.
In the flag plication technique, two Babcock clamps are used to
raise the eventrated dia-phragm, and the created fold is fixed at
its base with U-shaped heavy silk sutures (Fig. 19-2A). This
plicated area is then folded and resutured close to the intercostal
insertion of the diaphragm by one or several rows of additional
stitches (see Fig. 19-2B).
In the accordion plication technique, the eventrated diaphragm
is pulled in a radial direc-tion, and folds are created by placing
full-thickness sutures in the anterolateral to postero-medial
direction (Fig. 19-3A). In this manner, the diaphragm can be
plicated with as many rows of sutures as necessary to tighten it
(see Fig. 19-3B).
Other techniques that can be carried out through an open
thoracotomy include mechanical stapling of the base of the
eventration, incising the eventration and folding it onto one side,
or plicating the fold with U-shaped sutures placed over one or two
right-angle clamps. With this last technique, the created semilunar
fold is laid down and sutured again to reinforce the thinnest
portion of the eventration, usually its anterior part.
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Chapter 19 Diaphragmatic Eventration and Paralysis 205
A BFigure 19-2
Figure 19-3 A B
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206 Section II Thoracic Benign
2. Plication by Minimally Invasive Thoracoscopic Technique
This procedure, originally described by Mouroux, is carried out
through two 5-mm thora-coports and a mini-thoracotomy made over the
ninth intercostal space for the suturing of the diaphragm (Fig.
19-4A). The eventrated diaphragm is first pushed down toward the
abdomen (see Fig. 19-4B), and the created transverse fold is closed
with a back and forth continuous suture beginning at the periphery
of the diaphragm down to the cardiophrenic angle (see Fig.
19-4C).This is followed by a second row of continuous suture
burying the first suture line (see Fig. 19-4D). It is to be noted
that the presence of extended pleuropul-monary adhesions is
generally considered a contraindication to videothoracoscopic
plication.
3. Laparoscopic Plication
This technique for left-sided eventrations, which was described
by Httl, is done with the patient in a 30-degree reverse
Trendelenburg position where the surgeon is positioned between the
legs of the patient. The redundant diaphragm is pulled down and
plicated with 12 to 15 U-type sutures inserted from the left dorsal
portion of the diaphragm to its ventral medial portion.
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Chapter 19 Diaphragmatic Eventration and Paralysis 207
A B
C D
Port 15th ICS
Port 25th ICS
9th ICS
Figure 19-4
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208 Section II Thoracic Benign
Step 4. Postoperative Care
The postoperative care of these patients is usually fairly
straightforward with placement of one chest tube, which is removed
within 48 to 72 hours of the operation, and a nasogastric tube,
which is kept in place until abdominal peristalsis has resumed
(normally within 24 hours).
Step 5. Pearls and Pitfalls
In adults, diaphragmatic eventration rarely requires surgical
correction, except when respira-tory or digestive symptoms are
clearly related to the abnormality and other causes of elevated
hemidiaphragm have been ruled out. In selected patients, however,
there is evidence that diaphragmatic plication will provide
substantial and long-lasting benefits in terms of improv-ing
symptoms and lung function. The possibility of performing these
operations by less invasive techniques, such as video-assisted
thoracoscopy, may lead to new interests in these disorders and
their surgical treatment.
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Chapter 19 Diaphragmatic Eventration and Paralysis 209
Suggested Readings
Graham DR, Kaplan D, Evans CC, et al. Diaphragmatic plication
for unilateral diaphragmatic paralysis: A 10-year experience. Ann
Thor Surg 1990;49:248-252.
Httl TP, Wichmann MW, Reichart B, et al. Laparoscopic
diaphragmatic plication. Surg Endosc 2004;18:547-557.Lai DTM,
Paterson HS. Mini-thoracotomy for diaphragmatic plication with
thoracoscopic assistance. Ann Thorac Surg
1999;68:2364-2365.Mcnamara JJ, Paulson DL, Urschel HC, et al.
Eventration of diaphragm. Surgery 1968;64:1013-1021.Merendino KA,
Johnson RJ, Skinner HH, et al. The intradiaphragmatic distribution
of the phrenic nerve with particular reference to the
placement of diaphragmatic incisions and controlled segmental
paralysis. Surgery 1956;39:189-198.Mouroux J, Padovani B, Poirier
NC, et al. Technique for the repair of diaphragmatic eventration.
Ann Thorac Surg 1996;62:905-907.Mouroux J, Venissac N, Leo L, et
al. Surgical treatment of diaphragmatic eventration using
video-assisted thoracic surgery: A prospective
study. Ann Thorac Surg 2005;79:308-312.Piehler JM, Pairolero PC,
Gracey DR, et al. Unexplained diaphragmatic paralysis. J Thorac
Cardiovasc Surg 1982;64:861-864.Schumpelik V, Steinan G, Schlper I,
Preschner A. Surgical embryology and anatomy of the diaphragm with
surgical applications. Surg
Clin North Am 2000;80:213-239.Thomas TV. Congenital eventration
of the diaphragm. Ann Thorac Surg 1970;10:180-192.Wright CD,
Williams JG, Ogilvie CM, et al. Results of diaphragmatic plication
for unilateral paralysis. J Thorac Cardiovasc Surg
1985;90:195-198.
Diaphragmatic Eventration and ParalysisSurgical
AnatomyPreoperative ConsiderationsOperative StepsOpen
Posterolateral ApproachPlication by Minimally Invasive
Thoracoscopic TechniqueLaparoscopic Plication
Postoperative CarePearls and PitfallsSuggested Readings