Hematuria

Hematuria following SWL is one of the most common findings and usually resolves within a few hours. The effect in vessels can be differentiated by measuring α2‐macroglobulin enhancement found immediately after and 1 day following SWL [3–5]. Changes in specific hemostatic biomarkers in venous blood samples, at least during the first 4 hours post‐SWL, underline this side effect [6].

Detoriation of renal function

Several blood and urine markers can indicate possible renal injury shortly after SWL. Glomerular filtration rate, β2‐microglobulin measures in serum and urine, as well as serum creatinine measures after SWL treatment suggest that ESWL does not have any long‐term effect on the glomerular filtration rate; however, it leads to transient proximal tubular dysfunction for up to 7–9 days. Early retreatment, at least with piezoelectric sources, does not enhance several marker measures, in particular proteinuria. [5, 7]. Transient proteinuria, however, might last for up to 3 months until a return to baseline [8].

In an animal model it has been shown that small kidneys tend to show more tissue damage when exposed to SWL [9]. Looking at the smaller kidneys of children treated with SWL by analyzing urinary enzyme levels, the regeneration time of tubular function in children appears to be longer than for adults (14 versus 7 days) [10].

Renal colic (manageable conservatively)

The probability of suffering from renal colic during fragments passing down the ureter appears to be about 2–4% [11]. However, it does depend in several predisposing factors, such as stone size. Most of these events can be managed by oral medication and should be counted as expected side effects. However, colic, including the development of steinstrasse, that requires intervention or emergency room visits is a complication and discussed later in the chapter.

Steinstrasse

Steinstrasse is an accumulation of stone fragments or stone gravel in the ureter, which does not pass within a reasonable period of time and interferes with the passage of urine [12, 13]. Steinstrasse occurs in 4–7% of cases following SWL [14–16], and the major risk factor for the formation of steinstrasse is stone size [15].

Although Coptcoat’s classification of steinstrasse exists (Type I, fragments <2 mm in diameter; Type II, leading fragment 4–5 mm tailed by 2 mm particles; and Type III, consisting of large fragments), it is not widely used [13].

Clinically, steinstrasse can be symptomless or present with combinations of flank pain, fever, nausea and vomiting, or bladder irritation. Steinstrasse can cause obstruction of the ureter, which can be silent in up to 23% of cases [15] and can lead to failure of the function of the kidney [17]. In solitary kidneys anuria occurs in 5% of cases [15]. The insertion of a ureteral stent before ESWL might prevent formation of steinstrasse [18].

When steinstrasse is not symptomatic, conservative treatment is an initial option, depending on patient preference and the willingness to comply with a close surveillance schedule. Medical expulsive therapy might significantly increase stone expulsion rate and decrease need for endoscopic intervention [19, 20]. The patient should be informed about the controversial literature on medical expulsive therapy using alpha‐blockers as well as its off‐label use [21].

In cases where spontaneous passage is unlikely and interventional treatment becomes necessary, several options apply: SWL is one of the options in asymptomatic or symptomatic cases with no evidence of urinary tract infection, when large fragments of stones are presented [22]. There is an 80% chance of clearance of the steinstrasse [14].

Ureteroscopy is more effective but more invasive than SWL in treating steinstrasse (73–90%) [22–24].

Placement of a percutaneous nephrostomy tube is indicated in cases of symptomatic ureteric obstruction with or without urinary tract infection, and it is effective in 83% cases [14].

Colic needing intervention

When conservative treatment of renal colic fails intervention therapy is indicated. Choosing the treatment method in cases when signs of urinary tract infection are not presented is based on size, location, and X‐ray density of the blocking stone fragment. As in the treatment of ureteric stones, SWL or ureteroscopy is indicated [25]. Insertion of double‐J stent or percutaneous nephrostomy tube is indicated in cases complicated by urinary tract infection.

Infectious complications

Infectious complications of SWL are caused by renal trauma and vascular damage during SWL, facilitating bacteria to migrate into the blood vessels. Duvdevani et al. [26] showed in a prospective evaluation of 15 000 SWL treatments that bacteriuria after SWL occurred in 5.1% in spite of preoperative sterile urine. The most common pathogens were Escherichia coli (35.1%), Pseudomonas aeruginosa (16%), Klebsiella pneumoniae (12.8%), Proteus mirabilis (11.7%), Enterococcus faecalis (8.5%), and Enterobacter cloacae (4.3%). The risk of fever >38 °C, however, was only 1.4%. The probability of fever and bacteriuria is increased when an untreated or symptomatic urinary tract infection is present, a double‐J catheter or nephrostomy tube is inserted, or when treating struvite stones (17.7 vs. 2.1%, P < 0.05) [27].

No standard antibiotic prophylaxis before SWL is recommended. However, in view of the abovementioned risk factors prophylaxis is recommended in the case of internal stent placement ahead of anticipated treatments and in the presence of increased bacterial burden (e.g. indwelling catheter, nephrostomy tube, or infectious stones) [28–30].

Hematoma

On using computerized tomography routinely after SWL, perinephric soft‐tissue stranding and fascial thickening were seen in up to70%. In addition, hematomas may be detected in 15%, being big in 2% [31], and using magnetic resonance subcapsular or perinephric fluid can be seen in up to 26% of cases [32]. Routine ultrasound after SWL detects hematomas in approximately 4%. The probability of developing a hematoma increases significantly with patient age. However, most of these changes remain asymptomatic [33]. The effect might depend on the lithotripter being used [34, 35].

Potential risk factors for hematoma development are any kind of coagulopathy including that induced by medication, hypertension, diabetes mellitus, coronary artery disease, obesity, and obviously age [35, 36].

In most cases hematomas are, or become, asymptomatic and might resolve within 2 years. Krishnamurthi and Streem followed 19 patients with post‐SWL hematomas found on routine ultrasound for up to 61 months (mean 19.6 months). They showed a complete resolution of the hematoma in 85.7%, a significant reduction in 9.5%, and just one patient remained unchanged. There was no new onset or aggravation of pre‐existing hypertension [37].

Stepwise voltage ramping can reduce the risk of developing hematomas (odds ratio 0.39, 95% confidence interval 0.19–0.80; P = 0.01) [38] in addition to considering the above mentioned risk factors [38].

Cardiovascular complications

The incidence of cardiac of dysrhythmias varies from between 11 and 59% during ungated SWL [39, 40]. No correlation was mentioned between evidence of dysrythmias and type of lithotripter, number of shock waves, patient age, stone size and location, and type of anesthesia [39].

The incidence of morbid cardiac events or biochemical myocardial injury is extremely rare [41, 42].

Patients with a pacemaker can be treated with SWL, provided that appropriate technical precautions are taken; patients with implanted cardioverter defibrillators must be managed with special care (firing mode temporarily reprogrammed during SWL treatment). However, this might not be necessary with new‐generation lithotripters [43, 44].

The SWL treatment in patients with aortic aneurysm is controversial. There are reports of rupture of aortic aneurysm due to SWL treatment [45, 46] and reports of safe treatment [47]. According to Tse et al.’s review of 18 SWL treatments in patients with aortic aneurysm, there is currently no high‐level evidence to suggest that SWL in the presence of arterial aneurysm is unsafe [48]. However, an aneuryma in the vicinity of the stone and focal zone of SWL remain a contraindication for SWL treatment [36].

Gastrointestinal complications related to SWL treatment

Gastrointestinal damage has been reported as a rare potential complication of SWL. The actual incidence is unknown. In a review, Maker and Layke reported 62 cases of gastrointestinal damage of 3423 patients (1.81%); only 28 (0.82%) were symptomatic, including nine bowel perforations [49]. The etiology of gastrointestinal damage is unknown; however, the majority of cases were reported in patients treated in prone position and with a higher number of applied shock waves [49].

Gastric and duodenal erosions recorded by pre‐ and post‐ESWL endoscopy was found in 80% of the patients [50]. Ureterocolic fistula due to SWL [51] and dehiscence of gastrointestinal anastomosis [52] are reported, too.

Hepatic hematoma and spleen hematoma are rare complications of SWL. There were only 13 cases reported of hepatic [53] and seven of spleen hematomas [54, 55]. Due to the situation that the liver and spleen are intraperitoneal organs that lack a tough fascia, the need of surgical intervention is higher than in patients suffering post‐SWL renal hematomas.

Related posts:

1: Perioperative Considerations Shock‐wave Lithotripsy of Ureteral Calculi Percutaneous Treatment of Ureteropelvic Junction Obstruction Management of Urolithiasis in Pregnancy Patient Preparation and Operating Room Setup for Laparoscopic and Robotic Surgery Pelvic Lymphadenectomy

Stay updated, free articles. Join our Telegram channel

Join