Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5769_Библиотеки_им_академика_М_И_Перельмана
.pdf
450 oracic ultrasound
e second intercostal space on the midclavicular line (away from internal mammary vessels) is preferred for emergency drainage of PNX and for aspiration of small pneumothorax.
However, only tubes with caliber less than 18 Fr may enter here for the narrowness of the
intercostal spaces. e lateral (5th or 6th intercostal space) or posterolateral position is elective for drainage of pleural effusions and pneumothorax, and allows the passage of large tubes
(up to 40 Fr). To avoid the intercostal neurovascular bundle, the puncture or thoracostomy
is performed along the upper edge of the rib.
e use of ultrasound to determine the position of the diaphragm and its posterior or poste-
rolateral costophrenic angle facilitates the choice of the intercostal space to be used. Drains
should never be placed through infected skin areas or on previous drain accesses.
Figure 20 – Massive left PNX treated with 10 Fr pigtail. A: X-ray at the time of diagnosis. B: after
aspiration of air. C: the following day after catheter removal.
In recent years, an interest in the use of small and flexible drainage tubes (10-14 Fr) (catheters)
has risen. Small bore drainages have the advantage of being put in place with percutaneous
interventional techniques and, of course, avail themselves of ultrasound guidance. eir small
diameter allows an easy management of the catheter, decreases morbidity and is well toler-
ated by the patient (Fig. 20-21). e most frequent complications related to small catheters
are the block and malposition of the drainage (2-18% and 9%, respectively), visceral lesions
(2%) and infections (2%).
➣ Pleural effusions
e nature of a pleural effusion (exudate, transudate, empyema, etc.) is based on the study
of its physico-chemical, bacteriological and cytological characteristics. is represents the
first diagnostic step. e characteristics of the fluid also correlate with the evolutive stage of
the effusion18.
Interventional chest ultrasound 451
e nature of the effusion, in particular its density and inhomogeneity, affects the urgency,
the methods and the material used for drainage (such as the caliber of catheters). is is
particularly significant in pleural empyema.
e initial stage of an inflammatory (exudative) effusion is characterized by a mild proteic
fluid, easy to drain with a simple 18 G needle. e fibrinous/purulent (septic) phase is characterized by a viscous liquid with increased cellularity, and by the deposition of fibrin, which
tends to encapsulate the liquid in a spider web-like arrangement (alveolar appearance). e
third phase is organizational, and is mainly composed of fibroblast infiltration.
More advanced these steps are and more often a targeted ultrasound-guided approach is
needed, mainly for choosing large diameter tubes (12 Fr or larger). Sometimes the effusion
requires a surgical approach
19
.
Figure 21 – Ultrasound images of a needle into the pleural fluid during thoracentesis. a: coaxial scan
(in plane) with needle. b: transverse scan (out of plane) to the axis of the needle. Typical reverberation
artifact caused by the metal are evident.
e treatment of infective pleural effusions and hemothoraces require a separate discussion.
Most of the effusions are mild transudates or exudates, which are easily drained with 16-18 G
needles or 10-14 Fr catheters.
Blind, clinically directed aspiration is easy when a relatively large effusions, free in the serous
cavity, exists. Small effusions often have no clinical or radiographic evidence, so a puncture
can expose to failure or future complications. ese eventualities are not rare, occurring in
over 50% of the cases20.
PNX may be a complication of thoracentesis21, occurring much more frequently in the case
of procedure without ultrasound guidance (18% vs 3%)22.
452 oracic ultrasound
Loculated collections may have unusual locations and their position is not easily determined
with clinical tools.
Sonography is a very sensitive examination for detecting pleural effusions and for the evaluation of their characteristics (position, echogenicity, corpuscular structure, encapsulation due
to adhesions and so on).
e ultrasound examination, performed with the patient sitting or lying with the trunk
elevated 30-60 degrees, according to the posterolateral and posterior scans, smoothly directs
the needle and avoids a wrong insertion. is prevents puncture of the lung or the diaphragm,
or the transfixion of costophrenic angles
22-23
.
e safety of ultrasound-guided thoracentesis has also been demonstrated in patients undergoing mechanical ventilation. ese subjects are particularly at risk of developing complications24.
e tip of a needle in a fluid collection is usually shown by ultrasound. Using the techniques
described above, it is easy to place a drainage catheter in a cavity in order to empty the collection (Fig. 21).
Ultrasound also allows to immediately demonstrate a possible iatrogenic or ex vacuo pneumothorax, or a re-expansion pulmonary edema
25-26
.
Costophrenic cannulation technique
It is a variant of the echoguided thoracentesis (or pleural puncture for the insertion of a
catheter). It may be used both for simple drainage with needle or to introduce small-caliber
catheters by guidewire. Costophrenic puncture consists of inserting a needle by coplanar approach (in plane), with the probe aligned in an intercostal space, so that it penetrates along
the posterolateral costophrenic angle, almost parallel to the chest wall.
Our technique involves the use of Veres needle with retractable tip, which makes a traumatic
contact with the lung extremely rare, also in the final stages of the drain when the fluid is
low (Figs. 22-23).
Figure 22 – Set for chest drainage. The squares illustrate the Veress needle with its blunt tip, that
retracts to allow the needle to pass through the chest wall.
Interventional chest ultrasound 453
Diaphragm
Figure 23 – Sequences of ultrasound-guided thoracentesis through the costophrenic angle. On
the bottom right box: ultrasound image with the needle immediately above the diaphragm into the
posterolateral costophrenic angle.
Needle
With this approach, the patient may take the position he wants (typically supine with the trunk
and the affected side slightly raised). It is almost never necessary that the patient is sitting.
Anesthesia of skin, subcutaneous tissue, periosteum (the top edge of the rib) and pleural plane
must be accurate and is performed with 25 G needle, under ultrasound control.
e Veres needle insertion in the costophrenic angle is directed upwards and to the rear, along
the intercostal plane under constant view. After penetration into the pleural cavity, the needle
takes a position almost parallel to the wall, avoiding any possible contact with the lung. e
drainage of liquid, either through needle or catheter, is performed under ultrasound guidance.
is allows to monitor the expansion of atelectatic lung during drainage, in order to retract
the needle when the expanded lung approaches the chest wall.
In our experiencee, the re-expansion pulmonary edema is rare, even after drainage of large
amounts of fluid (> 1200 ml)27. In agreement with other authors, postprocedural control for
pneumothorax is implemented directly with ultrasound28.
Infections of the pleural cavity
Empyema is described separately for its frequency and gravity. Empyema often has a complicated course and it is characterized by the need to act without delay to an efficient drainage29.
Ultrasound diagnosis of an exudative effusion is relatively easy. In a study of 230 cases, all
sonographically echogenic effusions were exudates and all homogeneously echogenic effusions
454 oracic ultrasound
were empyema or hemothoraces30. It is recognized that pleural infections affect especially at
the extremes of age.
is pathology is related to pneumonia, and favored by predisposing conditions such as
diabetes, immunosuppression, corticosteroid use, gastroesophageal reflux, alcoholism and
illicit drug use31.
Pneumonia is significantly associated with pleural effusion. Approximately 57% of patients
with pneumonia develops a pleural effusion, which usually recedes with antibiotic treatment,
especially if the thickness of the fluid is less than or equal to 1 cm32. However, many parapneumonic effusions become complicated effusions and empyema33. is evolution should
be prevented and early detected.
A purulent transformation shows a corpuscolar or an areolar picture due to the web-shaped
fibrin in the liquid34.
Aspects concerning the sonographic diagnosis and drainage have already been described.
Even in the absence of clinical signs, each subject with an infected pleural effusion requires
a pleural puncture. is may be easily carried out through the costophrenic angle, according to the technique previously described, using a 18-20 G spinal needle and following the
Pleural effusion.
Signs of pneumonia/sepsis
Large/symptomatic, dense,
alveolar, loculated effusion
Yes No
Catheter for drain
Improvement
No
Ultrasound evaluation of the
residual volume
Response
Evaluation of catheter function
Catheter replacement
Alternative imaging
Surgical treatment
Yes
Medical therapy
Revaluations
Diagnostic
puncture
Pus
Yes
pH < 7.2; Germs +; Culture +
Yes
No
Yes
No
Medical
therapy
Answer
No
Figure 24 – Decision algorithm in the case of pleural effusion associated with pneumonia or sepsis.
Interventional chest ultrasound 455
procedure in real time. e appearance and the physical-chemical examination of the fluid
drained affect the subsequent choices.
A catheter drainage (10 Fr or more) is indicated in the presence of at least one of these
findings35:
• turbid or purulent fluid;
• liquid pH < 7,2;
• presence of bacteria in the Gram stain or positive cultures in non-purulent fluid;
• absence of improvement with medical therapy.
Neoplastic pleural effusion
Probably ineffective
pleurodesis.
Consider indwelling
catheter
YES
Symptomatology
YES
Drainage to control
symptoms
Prognosis > 1 month
Completely trapped
lung?
YES
NO
NO
Intermittent aspirations
NO or doubt
Pleural drainage +
pleurodesis with tube
Trapped lung?
Observation
Indwelling catheter or
new pleurodesis
NO
Effective pleurodesis?
Figure 25 – Flow-chart for the treatment of neoplastic pleural effusions.
NO
YES
STOP
456 oracic ultrasound
In our opinion, a pleural catheter drainage is indicated in the presence of fibrinous or alveolar
(complex set) effusions, if the liquid is echogenic, or when symptoms exist.
A 10-14 Fr catheter is adequate in many cases. However, an areolar effusion is predictive of a
worse outcome and of a high probability of admission in ICU after drainage with small tubes
(12-16 Fr)36. e pleural catheter may be put in place with one of the techniques described.
A low posterolateral access is preferred, using a Veres needle or, alternatively, the Seldinger
technique or a special needle/catheter kit.
Figure 24 exemplifies the decision algorithm in accordance with the British oracic Society
criteria35. In the case of empyema or septic fluid, drain removal is indicated when the radiographic and sonographic findings suggest a resolution, and an objective absence of sepsis is
guaranteed. An observation period of 24 hours after the drain removal is useful.
Neoplastic pleural effusions
37
Pleural effusion is frequently observed in patients with neoplasia. e fluid is not always
related to the tumor itself, but sometimes heart failure, hypoalbuminemia and cachessia play
a key role. Not all of these effusions require invasive therapy.
True neoplastic effusions that do not respond to specific therapies, if symptomatic, may be
drained with small catheters (8-10 Fr). A sclerosing therapy with intrapleural injection of
talc, doxycycline, bleomycin or betadine may follow. Figure 25 summarizes the operative
options in neoplastic effusions.
Small bore drainages allow a home treatment, guarantee a better comfort for the patient and
are easily put in place by means of ultrasound guidance. Ultrasound identifies the best point
of access to the pleural cavity, assesses the characteristics of the effusion (typically fibrinous
or areolar) and allows the positioning of drainage away from fibrinous branches and pleural
masses. Ultrasound is also necessary for the treatment of loculated collections.e success
rate of small tube drainage is high (53-81% complete regression and 95% partial response),
similar to that achieved by drainage by greater caliber
38-39
.
An important problem related to neoplastic pleural effusions is the failure of the lung reexpansion after fluid removal. is may be due to diffuse pleural thickening (trapped lung),
pleural loculations, obstructive atelectasis or persistent air leak. If a lung does not re-expand,
symptoms may not resolve and treatment with sclerosing agents may not be effective. e
drainage of pleural fluid with a trapped lung may favor the occurrence of re-expansion
pneumothorax.
Intrapleural fibrinolytic therapy
Intrapleural administration of fibrinolytic agents has been used to increase the drain in subjects
with areolar, multiloculated parapneumonic infections, empyema or malignant effusions.
Streptokinase (SK), urokinase (UK) and r-tPA are the most commonly used fibrinolytics.
However, the effectiveness of the procedure is debated.
In a retrospective study, Temes et al described the use of SK or UK for fibrinolysis in patients
with empyema. A complete resolution of symptoms and radiographic findings was achieved
in 62% of cases. Bleeding complications occurred in 4%.
e effectiveness of fibrinolytic therapy with r-tPA in loculated effusions (6 mg in 50 mL of
saline for two hours), was reported by Zuckerman (72% complete clinical and radiographic
resolution without bleeding complications). If incomplete drainage, r-tPA can be repeated
every 12 hours for six times.
Interventional chest ultrasound 457
On the contrary, the Multicenter Intrapleural Sepsis Trial demonstrated that intrapleural SK
in patients with empyema was not effective in reducing mortality, surgery or the length of
the hospital stay.
Similar results appear in Tokuda’s meta-analysis of five randomized trials comparing fibrinolysys
versus placebo. We use intrapleural fibrinolytic therapy with good results when the fibrinous
strands are large or when the effusion is web-like.
Pneumothorax after thoracentesis in unexpandable lung
40
e unexpandable lung is characterized by inability of the organ to reach the chest wall, so the
normal interactions between the visceral and parietal pleura are lost. is may be secondary to
visceral pleura fibrosis, bronchial obstruction resulting in lobar collapse or chronic atelectasis.
Unexpandable lungs are constantly associated with pleural effusion.
Some patients with unexpandable lung show classical clinical features after thoracentesis:
1. development of unexpected PNX;
2. inability to fully expand the lungs;
3. inability to completely drain the pleural fluid for the onset of chest pain.
e pleural effusion in this case has generally neoplastic or inflammatory nature.
As already pointed out, the iatrogenic pneumothorax after ultrasound-guided thoracentesis
is a rare event. When it occurs, the underlying cause is frequently the presence of an unexpandable lung.
e pathophysiology of “thoracentesis-related pneumothorax” is thought to be due to a
pressure-dependent pleuropulmonary fistula. is is caused by the incapacity of the unexpandable lung to adapt to the volume of the thoracic cavity after aspiration of the liquid.
ese PNX rarely need to be treated (Figs. 26-27-28) (Clips 1-2).
Figure 26 – Chest radiograph in a patient suffering from lung cancer, who develops a pneumothorax
after thoracentesis. The hydro-PNX is confined to the base of the left lung.
458 oracic ultrasound
Figure 27 – CT scan of the same patient: hydro pneumothorax confined to the lung base.
Figure 28 – Inexpandible lung in a patient with pleuropulmonary metastases (soft tissue sarcoma).
Top left: pleural effusion. Top right: ultrasound guided catheter insertion for draining left pleural
effusion. During the procedure, ultrasound demostration of left pneumothorax. Chest X-ray confirms the
pneumothorax. Below: CT demonstrating left pneumothorax with an inexpandable lung. No therapy.
Interventional chest ultrasound 459
Clip 1 – Echographic situation of the patient in Figures 18 and 19. There is
no pleural sliding in the area adjacent to the loculated effusion, which is likely
expression of pleurodesis.
Clip 2 – Echographic situation of the patient in Figures 18 and 19.
Pleural effusion and air artifacts floating in sloping areas are visualized
(hydropneumothorax).
Ex vacuo pneumothorax
Ex vacuo pneumothorax must be distinguished from the pneumothorax caused from an
inexpandable lung after thoracentesis. Ex vacuo pneumothorax is not related to pleural
intervention. It comes off when acute bronchial obstruction from mucous plugs, aspirated
foreign bodies, or badly positioned endotracheal tubes cause acute lobar collapse and a significant increase in negative intrapleural pressurearound the collapsed lobe. erefore, gas is
attracted into the pleural space while the seal between the visceral and parietal pleura of the
adjacent lobes remains intact.
Sonographic signs of ex vacuo pneumothorax, including lung points, are in atypical position
and do not respect the antigravitational arrangement of the free intrapleural air. If an associated pleural effusion is present, signs of localized hydropneumothorax can be seen. Because
the presence of air, the atelectatic lobe may be hidden, and, therefore, a precise sonographic
diagnosis may be difficult, if this condition is unknown. Correct interpretation of this kind
of pneumothorax is crucial in directing treatment, which consists of relieving the bronchial
obstruction rather than inserting a useless chest tube into the pleural space.
Pleurodesis
In the patient with neoplastic effusion or pneumothorax, drainage of pleural fluid or air with
a small-caliber catheter (10-14 Fr) may be completed with the instillation of sclerosing agents,
that will prevent the collection to develop again. is may be achieved by various techniques
that employ large, small tubes (catheters) or video-assisted thoracoscopic surgery (VATS).
ree randomized trials have evaluated the efficacy differences between large and small tubes,
and have shown that the results are comparable
41-43
.
Pleurodesis is performed by instilling chemical agents into the pleural cavity, after draining
the fluid and with the fully expanded lung44. To this end, the reduction of pleural fluid below
a certain level (e.g. < 150 ml/day) is not necessary, but it is helpful to drain as much liquid as
possible. After the sclerosing substance has entered into the pleural cavity, the maintenance
of a drainage catheter or continuous pleural suction does not seem relevant.
e lack of complete re-expansion of the lung hinders pleurodesis. e percentage of trapped
lung compatible with an effective pleurodesis is not known. erefore, in case of partial expansion, the drain remains in the pleural cavity, and if necessary the pleurodesis procedure may
be repeated. Even a partial re-expansion may however lead to favorable results45.
Соседние файлы в папке Библиотека им академика М.И. Перельмана