Small-Bore Catheter Drainage of Pleural Injury After Percutaneous Nephrolithotomy: Feasibility and Outcome from a Single Large Institution Series

Introduction

Although percutaneous renal drainage has been used since the mid-1860s, stone removal via percutaneous access was not described until Fernström and Johansson ¹ performed a stone removal in 1976. Significant advances in percutaneous stone removal in both technique and equipment have made great strides in stone surgery. In modern endoscopic centers, percutaneous nephrolithotomy (PCNL) has virtually eliminated the necessity for open stone surgery. Ultrasonic lithotriptors, laser lithotripsy, high definition visualization, improved rigid and flexible instrumentation, using multiple puncture sites have all contributed to improving stone-free rates. ²

There have also been significant advances in decreasing the morbidity associated with PCNL by decreasing the amount of postoperative narcotic use, decreasing the needed hospital stay, and avoidance of an external drainage device. Decreasing the size of nephrostomy tubes (8–20F down from 20–28F), in addition to the increasing use of tubeless and stentless PCNL, have helped reduce patient morbidity. ^{3 –5} Advancing technology and techniques to better care for patients should also be used when complications to procedures are encountered.

Complications associated with PCNL are well known and established. These include immediate and delayed hemorrhage, sepsis, damage to adjacent organs (colon, duodenum, jejunum, spleen, liver, and biliary system), and pleural injury or lung injury. Although subcostal (below the 12th rib) superior pole access is the preferred access point for the majority of PCNLs, it is sometimes necessary to access the kidney via the intercostal space between ribs 11 and 12. Entrance between ribs 10 and 11 is rarely needed and significantly increases both pleural injury and potential injury to the lung. Thorascopic guidance has been described to allow safe entry with supracostal access. ⁶

Regardless, the risk for pleural invasion during percutaneous access and subsequent PCNL is well established. The risk of pleural invasion increases as the access to the kidney moves cephalad. The incidence of pleural injury (hydrothorax, pneumothorax, hemothorax, and urinothorax) is less than 0.5% when percutaneous access is below the 12th rib. ^{7 –9} Percutaneous access above the 12th rib on average has a 4.6% injury rate, while access above the 11th rib is 24.6%. ^{7 –24} Because of the increased risk of injury, formal chest radiography is recommended after cases of supracostal percutaneous renal access.

Although thoracostomy drainage is not always necessary in patients with radiographic evidence of pneumothorax of pleural effusion, if the effusion is large or there is clinical respiratory compromise and/or hemodynamic instability, a thoracostomy drain is needed. This study aims to better delineate the clinical outcomes of pleural injury after PCNL managed with small-bore pigtail chest tubes compared with standard chest tube placement at a single institution.

Patients and Methods

A single institution retrospective review of 735 consecutive renal units that underwent percutaneous procedures from 2001 to 2013 was performed. Patients who did not undergo formal dilation above 24F during the PCNL and those who received a chest tube for indications other than a pleural injury resulting from a PCNL were excluded from the data set. An upright chest radiograph was obtained in the recovery room after every percutaneous renal surgery in which the patient underwent dilation. Thus, a chart review and examination of postoperative chest radiographs was performed to identify all patients in whom chest tube placement was necessitated. Primary clinical outcomes were length of time the chest tube was in place, hospital length of stay (LOS), and partial or complete resolution of the pleural complication. Outcomes were compared using the chi-square test, Mann-Whitney U test, Student t test, where appropriate, with P values representing two-tailed measures of statistical significance.

Results

Of the 735 percutaneous procedures, 15 (2%) necessitated chest tube placement for a pleural injury after the procedure. All percutaneous procedures that needed chest tube placement were performed to remove a renal calculus, with a median stone size of 1.6 cm. Of those 15 renal units with pleural injury, 7 were right sided, 8 were left. Five standard large-bore (32F) chest tubes and 10 small bore (<14F) were placed to manage the pleural injury. Of the 15 chest tubes placed, 10 were performed by an interventional radiologist after the PCNL was complete, and these were all small bore. Of the five standard-size chest tubes placed, two were placed in the operating room (one by the general surgery service, one by the urologic surgery service) and three were placed in the postoperative recovery room by the general surgery service.

The average length of time the chest tube stayed in placed for small-bore chest tubes was 3 days (minimum 1, maximum 5), large-bore chest tubes was 3.8 days (minimum 2, maximum 7), and all chest tubes was 3.3 days (minimum 1, maximum 7). The average length of time in the hospital after the PCNL was completed was 3.9 days (minimum 2, maximum 6), large-bore chest tubes was 4.4 days (minimum 2, maximum 7), and all chest tubes was 4.1 days (minimum 2, maximum 7) (Fig. 1). There was not a statistically significant difference between the length of time the chest tube was in place (P=0.47) or with the length of stay in the hospital after the PCNL was completed, based on chest tube size (P=0.64). See Tables 1 and 2 for a summary of data.

OPEN IN VIEWER

FIG. 1.

Comparison of average length of stay (LOS) and tube duration for small and standard chest tubes.

Residual pnuemothorax or pleural effusion after chest tube removal was determined via chest radiography. Although not statistically significant (P=0.121), there was a trend for complete resolution of pleural effusion and or pnuemothorax with the use of a small-bore chest tube (20% residual chest radiography finding) rather than a standard chest tube (60% residual chest radiography finding), as shown in Table 2. All positive chest radiography findings were deemed to be clinically insignificant and resolved spontaneously without need for further treatment.

Discussion

There is a paucity of urologic literature defining the optimal care for those patients who have hydrothorax and/or pneumothorax after PCNL. The indications for a chest tube, what size, and type of chest tube to place varies widely from institution to institution. Placement can be performed in the operating room at the time of PCNL if fluoroscopy shows a large effusion with coinciding difficulty ventilating the patient. A standard 30+F chest tube can be placed, but placement of an 8F to 12F small-caliber tube can also been performed using fluoroscopic guidance. What service places the chest tube and the timing of tube placement (intraoperative or postoperative) can also dictate the type of tube placement.

In our data, all small-bore chest tubes were placed by the interventional radiology service after the completion of the PCNL, while all standard chest tubes were placed by the general surgery service or the urology service, either in the operating room or immediately in the postoperative recovery area. This is likely because of the comfort level with the specific technique used for the chest tube placement. Cardiothoracic/general surgery may be more comfortable with a formal 30F tube. Interventional radiologists are more comfortable with fluoroscopically guided small-bore chest tubes. Urologists may be comfortable using both former general surgery training to place the standard chest tube or endoscopic training using a modified Seldinger technique to place small-bore drainage tubes. ²⁵ Not all subclinical pneumothorax and hydrothorax require a chest tube, and some may resolve/drain on their own. Thus, the incidence of clinically significant hydrothorax and the type and timing of chest tube placement is variable depending on the clinical scenario.

The indications for a chest tube are many: Malignant pleural effusions, parapneumonic effusions/empyema, hemothorax, chylothorax, chronic recurrent pleural effusions, hydrothorax, and pneumothorax. Within the endoscopic urologic realm, hydrothorax and pneumothorax far outweigh other indications for chest tube drainage. Rarely, a urinary fistula can develop and necessitate drainage. Traditional cardiothoracic teaching was that if a chest tube was needed, a large-bore (>28F) chest tube was placed via a blunt dissection technique. Over the last 20 years, it has been increasingly common to use smaller bore chest tubes via a Seldinger technique for drainage of pleural effusions and pneumothorax. ^{26 –28}

The literature from cardiothoracic and interventional radiology has shown that there is less morbidity, pain, and complications from placement of small-bore chest tubes compared with standard chest tubes. The smaller chest tubes (<14F) have less pain during insertion and maintenance and are easier to place. ²⁶ In general, there are fewer complications associated with smaller chest tubes. Havelock and associates ²⁹ showed that the incidence of inadvertent injury with large-bore vs small-bore thoracostomy tubes was 1.4% vs 0.2%, the incidence of malposition was 6.5% vs 0.6%, and the incidence of empyema was 1.4% vs 0.2%. Small-bore thoracostomy did have an increased incidence of drain blockage (8.1% vs 5.2%) with large tubes.

There are limitations to this study. This study is a retrospective chart review, which inherently limits completely accurate and unbiased data acquisition. The strengths of this study are the large volume of the PCNL data set and the consecutive nature of the cases. While the data are not definitive, we believe that this study does support the use of small-bore catheters for management of pleural complications after PCNL, because they appeared to have similar efficacy to standard large-bore chest tubes for the management of such complications. A future study could focus more on the other potential advantages of small-bore catheters, such as reduced discomfort to the patient and the feasibility for outpatient management of a pleural complication.

Conclusion

Hydrothorax and pneumothorax are well known complications after percutaneous renal surgery. The use of small bore catheters (8–12F) as chest tubes to manage hydrothorax and pneumothorax have clinical outcomes that are similar to those for standard large-bore chest tubes. Because of the infrequency of this complication, further data will need to be acquired to obtain statistical significance to prove that there is a decreased amount of hospital stay and length of time the chest tube is in place with small-bore catheter drainage. With the decreased morbidity and complication rate with small-bore catheter thoracostomy and equivalent clinical outcomes in this urologic population, it is recommended to use small-bore catheters for management of hydrothorax and pneumothorax after PCNL.