Eitan Podgaetz and Rafael S. Andrade
INDICATIONS/CONTRAINDICATIONS
Laparoscopic diaphragmatic plication is a safe and effective operation in carefully selected patients. Laparoscopic diaphragm plication was first reported by Hüttl et al. in three patients. We reported our experience with laparoscopic hemidiaphragm plication in 25 patients, and found that laparoscopic diaphragm plication significantly improves dyspnea, quality of life, and pulmonary function tests (PFTs) in patients with unilateral diaphragm paralysis or eventration.
The approach for hemidiaphragm plication should be individualized by patient anatomy, comorbidities, and surgeon experience. Regardless of approach, proper patient selection, safety, and a tight imbrication of the entire hemidiaphragm are essential. A transabdominal approach offers some theoretical advantages and disadvantages over a transthoracic approach for diaphragmatic plication.
Advantages
Supine decubitus
Ventilation with single-lumen endotracheal tube
Ample working space within abdominal cavity
Direct visualization of intra-abdominal organs to prevent injury during imbrication
Less postoperative pain
Disadvantages
Difficulty visualizing the posterior portion of the hemidiaphragm
Potential splenic or liver laceration
Technically demanding operation in centrally obese patients
Prospective candidates for diaphragmatic plication must have dyspnea that cannot be solely attributed to another process (i.e., poorly controlled primary lung or heart disease) and must have an elevated hemidiaphragm on a posteroanterior and lateral (PA/LAT) chest x-ray. Since the only goal of diaphragm plication is to treat dyspnea, operative intervention is indicated exclusively for symptomatic patients. An elevated hemidiaphragm or paradoxical motion per se do not merit surgery in the absence of significant dyspnea. Morbidly obese patients should be evaluated for medical or surgical weight loss prior to diaphragmatic plication, since dyspnea may improve after significant weight loss and plication may no longer be required. Technically, any type of plication is challenging in the morbidly obese patient: The degree of plication may be compromised due to technical difficulties, the relief of dyspnea may be limited, and complications may be more common than in normal BMI patients. Patients with neuromuscular disorders should be approached with extreme caution as their symptomatic improvement is moderate at best, and complications are common. It is necessary to approach patients with morbid obesity and neuromuscular disorders in an individualized multidisciplinary fashion to decide if a plication will improve the patient’s condition.
Relative contraindications to a laparoscopic approach to diaphragm plication include previous extensive abdominal surgery, BMI >35, and comorbidities that may worsen with pneumoperitoneum (e.g., chronic renal failure, history of deep venous thrombosis). Morbidly obese patients pose particular technical challenges due to hepatomegaly from steatosis or excessive omental fat in the left upper quadrant.
PREOPERATIVE PLANNING
Clinical Evaluation
The diagnosis of symptomatic hemidiaphragm paralysis or eventration is primarily clinical, and relies mostly on history, chest x-ray, and the physician’s clinical acuity.
The evaluation of a symptomatic patient with hemidiaphragmatic paralysis or eventration should include an objective assessment of dyspnea, physical examination, PFTs, and imaging studies.
A careful respiratory history on the duration and progression of dyspnea and orthopnea is essential. Any potential additional causes of dyspnea (e.g., morbid obesity, primary lung disease, heart failure, etc.) need to be investigated and corrected if possible, since dyspnea secondary to diaphragmatic paralysis or eventration is largely a diagnosis of exclusion.
All patients with dyspnea secondary to an elevated hemidiaphragm or eventration should fill out a standardized respiratory questionnaire to evaluate the severity of their symptoms as objectively as possible and to assess the response to treatment.
Pulmonary Function Tests
PFTs provide relative objectivity to the assessment of dyspneic patients with an elevated hemidiaphragm; however, PFTs are imprecise and do not correlate well with severity of dyspnea or response to plication. Diaphragm dysfunction reduces the compliance of the chest wall; hence, a restrictive pattern (i.e., low forced vital capacity [FVC] and low forced expiratory volume in 1 second [FEV1]) is the norm.
The diaphragm is the principal inspiratory muscle; therefore, assessing inspiratory PFT parameters (i.e., maximum forced inspiratory flow [FIFmax]) may be of added value.
FVC should be measured in the upright and supine position; supine FVC in healthy individuals can decrease up to 20% from upright values, and supine lung volumes may decrease by 20% to 50% in patients with hemidiaphragmatic eventration or paralysis.
Imaging Studies
Chest x-ray
On standard full-inspiratory PA/LAT chest x-ray, the right hemidiaphragm is normally 1 to 2 cm higher than the left. Hemidiaphragm elevation can be a sign of diaphragmatic paralysis; however, this is nonspecific since a variety of pulmonary, pleural, and subdiaphragmatic processes can also elevate the hemidiaphragm. As a result, further studies may be necessary if an elevated hemidiaphragm is noted on a chest x-ray in the presence of dyspnea.
Fluoroscopic Sniff Test
During fluoroscopy, patients are instructed to sniff, and diaphragmatic excursion is evaluated. Normally, the diaphragm moves caudally, but in patients with hemidiaphragmatic paralysis, the diaphragm may (paradoxically) move cranially. Patients with diaphragmatic eventration, however, may also exhibit passive upward movement of the diaphragm when sniffing.
The clinical value of a sniff test is limited in the presence of an elevated hemidiaphragm and dyspnea. The principal role of the sniff test is to help discern the etiology of dyspnea in when it is not entirely clear if hemidiaphragm elevation is the main cause of dyspnea.
Fluoroscopic findings should be interpreted with caution. Approximately 6% of normal individuals exhibit paradoxical motion on fluoroscopy; to increase the specificity of this study, at least 2 cm of paradoxical motion should be noticed. Also, a paralyzed or eventrated hemidiaphragm may move very little or not at all, without paradoxical motion, making the interpretation of the sniff test and the distinction between paralysis and eventration even more difficult.
CT
The main utility of CT scans is to rule out the presence of a cervical or intrathoracic tumor as the cause of phrenic nerve paralysis or to evaluate the possibility of an infra- or supradiaphragmatic process as the cause of hemidiaphragm elevation. However, a CT scan is not routinely required if the clinical suspicion of an alternate process is low.
Other Tests
Other diagnostic tests such as ultrasonography, dynamic magnetic resonance imaging, maximal transdiaphragmatic pressure, and phrenic nerve conduction studies are of limited or no clinical value in the evaluation of a patient with dyspnea and an elevated hemidiaphragm on chest x-ray.
Clinical Evaluation Summary
Potential candidates for laparoscopic diaphragm plication have an elevated hemidiaphragm on chest x-ray and dyspnea; the minimal clinical assessment before a plication should include history and physical examination, evaluation of the severity of dyspnea with a validated standardized respiratory quality-of-life questionnaire, a PA and lateral chest x-ray, and PFTs. Fluoroscopic sniff test and CT scan are of value in select patients but are not mandatory.
SURGERY
Anesthesia
The procedure is performed under general anesthesia, with a single-lumen endotracheal tube; selective ventilation is not necessary.
Position
The patient is in the supine position with arms abducted. The abdomen and lower lateral chest wall are prepared and draped to allow access for chest tube placement, a foot board is essential for steep Trendelenburg positioning.
Operative Technique
1. Ports: We use four 12-mm ports; two assistant ports are placed 2 cm parallel to the midline on the opposite site of the elevated hemidiaphragm. The two working ports are placed in the ipsilateral upper quadrant (Fig. 19.1). We insufflate the abdomen with CO2 at a pressure of 15 mm Hg.
2. Exposure: Steep reverse Trendelenburg positioning helps optimize exposure of the posterior portion of the hemidiaphragm; for a right-sided plication, transection of the falciform ligament is useful for appropriate access to the diaphragm. The thinned-out hemidiaphragm is taut and displaced cranially as a result of pneumoperitoneum (Fig. 19.2A). We make a small perforation at the dome of the diaphragm with electrocautery (Fig. 19.2B). The resultant pneumothorax releases the tension on the hemidiaphragm and allows the surgeon to easily pull the hemidiaphragm into the abdominal cavity for suturing (Figs. 19.2C,D). At this point, we often place a 19 Blake pleural drain through an incision in the anterolateral chest wall to vent the pneumothorax as needed.
Figure 19.1 Port placement for laparoscopic left hemidiaphragm plication. A1, A2 = assistant ports (placed about 2 cm parallel to the midline on the right side); S1, S2 = surgeon ports (placed about 2 to 4 cm above the level of the umbilicus). Dotted lines represent the midline and a horizontal line at about ¼ to ⅓ the distance from umbilicus to xiphoid.
Figure 19.2 A: Cephalad displacement of the left hemidiaphragm following CO2 insufflation, the hemidiaphragm is taught and difficult to handle. B: A small opening with the electrocautery induces a pneumothorax. C: Floppy hemidiaphragm after pneumothorax. D: Easy manipulation of the floppy hemidiaphragm.
3. Stitching: We use pledgeted U-stitches (no. 2 nonabsorbable, braided suture, 31-mm curved needle). We place the first stitch centrally and as far posteriorly as possible (Fig. 19.3A). Traction on the first stitch facilitates exposure for two or three subsequent deeper stitches (Fig. 19.3B) to plicate the posterior portion of the hemidiaphragm in an anteroposterior direction (Figs. 19.3C,D). To plicate the anterior portion of the hemidiaphragm we use two to three weaving stitches (Fig. 19.4). The diaphragm must be taught at the end of the procedure (Fig. 19.5). Closure of the initial perforation at the dome occurs with the plication.
Figure 19.3 A: Placement of first pledgeted U-stitch in the central portion of the diaphragm. B: Retraction on the first stitch allows exposure for placement of two or three subsequent stitches in anteroposterior direction. C,D: Completed posterior plication with four stitches; the posterior portion of the hemidiaphragm is taught and the anterior portion is still displaced in cephalad direction. E: This shows “U”-shaped stitches with pledgets (blue rectangles) before tying them; the numbers show the sequence of placement starting in the middle of the left half of the diaphragm and progressing toward the back. The arrow shows the direction of placement of the stitches.
Figure 19.4 A: Placement of first of two to three weaving stitches, the arrows show the course of the U stitch in posteroanterior direction. B: The posterior three stitches seen in this figure have now been tied. Two anterior stitches have been placed on the anterior half of the left hemidiaphragm; they have not been tied yet.
4. Tube thoracosotmy: We leave the pleural drain in place upon completion of the procedure and verify that it has not been caught in a stitch.
5. Intraoperative management of lower lobe atelectasis: Upon completion of the plication, we ask the anesthesia team to ventilate the patient with high tidal volumes and a PEEP of 10 cm H2O until extubation with the intention to re-expand the lower lobe. If respiratory secretions are copious after recruitment, a flexible bronchoscopy should be performed.
POSTOPERATIVE MANAGEMENT
Postoperatively, we assure patients participate in intense pulmonary toilet to re-expand the lower lobe of the ipsilateral lung. The chest drain remains in place until output is less than 200 mL per day; occasionally patients need to be discharged with the chest tube in place. Premature removal of the chest drain can lead to symptomatic pleural effusion with recurrent lower lobe atelectasis. The immediate postoperative chest x-ray should show that the plicated side is lower than the opposite side with an acute costophrenic angle (Fig. 19.6), and that the opposite side is actually elevated in comparison to the preoperative chest x-ray. One month after surgery, both hemidiaphragms are about at the same level and should remain that way on long-term follow-up (Fig. 19.6). We monitor patients with the St. George’s Respiratory Questionnaire (SGRQ), PA/LAT chest x-ray, and PFTs at 1 month after discharge and yearly thereafter.
Figure 19.5 Completed plication.
Figure 19.6 Sequence of chest x-rays from a patient with left hemidiaphragm paralysis. Note the acute left costophrenic angle and the cephalad displacement of the right hemidiaphragm immediately postoperatively. At 1 month the hemidiaphragms have settled in new positions (a small left effusion can be seen); and at 5 years both hemidiaphragms remain unchanged from the 1-month follow-up CXR.
COMPLICATIONS
Complications of laparoscopic plication include prolonged chest tube drainage (>7 days) in approximately 8%, respiratory failure (4%), gastrointestinal hemorrhage (4%), splenic laceration requiring splenectomy (4%), stroke (4%), and atrial fibrillation (4%). The severity of some of these complications is probably also a reflection of the severity of comorbidities in this patient population.
TABLE 19.1 Comparison of SGRQ Score, FVC, and FEV1 before and 1 Year after Laparoscopic Diaphragm Plication in 25 Patients
RESULTS
Laparoscopic diaphragmatic plication achieves a very significant improvement in dyspnea at 1 month and 1 year after surgery. The total SGRQ scores improve on average by 20 points (≥4 points is considered clinically significant). PFTs improve on average by about 10%, an indication that FVC and FEV1 do not correlate well with symptoms in patients with hemidiaphragmatic eventration or paralysis. Table 19.1summarizes preoperative and postoperative (1 year) SGRQ scores and PFT in 25 patients. Figure 19.6 illustrates a representative series of chest x-rays in a patient with 5-year follow-up. Figure 19.7emphasizes the importance of a thorough posterior plication.
CONCLUSIONS
Properly selected patients with symptomatic hemidiaphragmatic paralysis or eventration benefit significantly from laparoscopic diaphragm plication as long as the surgeon adheres to basic principles of patient selection, safety, and tight imbrication of the entire hemidiaphragm.
Figure 19.7 This series of lateral views emphasizes the importance and persistence of the posterior plication in a patient with right hemidiaphragm paralysis.
Recommended References and Readings
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