Symptomatic nephrolithiasis complicating pregnancy

The identification of pregnant women with renal colic who may need surgical intervention

Background

Renal colic is a surgical emergency in pregnancy that is caused by a range of non-obstetric factors and known to occur more frequently during the second and third trimesters. Several studies have reported that up to 70–80% of stones pass spontaneously during pregnancy. There are some patients will not pass their stones and will ultimately require surgical intervention. Through retrospective analysis of the clinical data of 212 pregnant women with renal colic, the predictive factors of pregnant women with renal colic in need of surgical intervention were determined.

Methods

We conducted a retrospective review of 212 pregnant women presenting with renal colic between 1st January 2009 and 31st December 2020. Univariate and multivariate analyses identified a range of predictive variables for surgical intervention. In addition, we used receiver operating characteristic curve analysis to evaluate the predictive power of our model and created a nomogram for clinical application.

Results

Of the 212 patients presenting with acute renal colic in pregnancy, 100 patients (47.2%) underwent surgical intervention and 112 patients (52.8%) were treated conservatively. Univariate analysis identified significant differences between the two groups with regards to fever, the duration of pain, white blood cells, C-reactive protein, ureteral stone size, hydronephrosis, and stone location. Multivariate analysis further identified a number of independent predictors for surgical intervention, including fever, a duration of pain ≥ 4 days, a ureteral stone size ≥ 8 mm, and moderate or severe hydronephrosis.

Conclusions

We identified several independent predictors for surgical intervention for renal colic in pregnancy. Fever, a duration of pain ≥ 4 days, a ureteral stone size ≥ 8 mm, and moderate/severe hydronephrosis, play significant roles in predicting surgical intervention. Our nomogram can help to calculate the probability of surgical intervention in a simple and efficient manner. Prospective studies are now required to validate our model.

Catastrophic complications of urolithiasis in pregnancy

Urolithiasis is the most common non-obstetric complication in pregnancy and has the potential to cause grave consequences resulting in pregnancy loss. We present two such cases. First, a 24-year-old woman, 5 weeks pregnant with a history of urolithiasis presented with right flank pain and fever. She was found to have a right perinephric collection and during the course of her treatment suffered an abortion. The second case was a 25-year-old woman who presented in septic shock. She underwent emergency lower segment caesarean section elsewhere 10 days ago for intrauterine death at 38 weeks of gestation. On evaluation, she was found to have bilateral stone disease with a left subcapsular haematoma. Both the cases were managed conservatively and are planned for definitive management. Thus, women of childbearing age with diagnosed urolithiasis should get themselves evaluated and be free of stone disease before planning a family to prevent increased obstetric complications during pregnancy.

Risk of Symptomatic Kidney Stones During and After Pregnancy

RATIONALE & OBJECTIVE

There are several well-known anatomical and physiological changes during pregnancy that could contribute to kidney stone formation, but evidence that they increase the risk of kidney stones during pregnancy is lacking. We determined whether there was an increased risk of a first-time symptomatic kidney stone during and after pregnancy.

STUDY DESIGN

A population-based matched case-control study.

SETTING & PARTICIPANTS

945 female first-time symptomatic kidney stone formers aged 15-45 years and 1,890 age-matched female controls in Olmsted County, MN, from 1984-2012. The index date was the date of onset of a symptomatic kidney stone for both the case and her matched controls.

EXPOSURE

The primary exposure was pregnancy with assessment for variation in risk across different time intervals before, during, and after pregnancy. Medical records were manually reviewed to determine the conception and delivery dates for pregnancies.

OUTCOME

Medical record-validated first-time symptomatic kidney stone.

ANALYTICAL APPROACH

Conditional and unconditional multivariable logistic regression analysis.

RESULTS

Compared with nonpregnant women, the odds of a symptomatic kidney stone forming in women was similar in the first trimester (OR, 0.92; P=0.8), began to increase during the second trimester (OR, 2.00; P=0.007), further increased during the third trimester (OR, 2.69; P=0.001), peaked at 0 to 3 months after delivery (OR, 3.53; P<0.001), and returned to baseline by 1year after delivery. These associations persisted after adjustment for age and race or for diabetes mellitus, hypertension, and obesity. These results did not significantly differ by age, race, time period, or number of prior pregnancies. Having a prior pregnancy (delivery date>1year ago) was also associated with a first-time symptomatic kidney stone (OR, 1.27; P=0.01).

LIMITATIONS

Observational study design in a predominantly White population. The exact timing of stone formation cannot be determined.

CONCLUSIONS

Pregnancy increases the risk of a first-time symptomatic kidney stone. This risk peaks close to delivery and then improves by 1 year after delivery, though a modest risk of a kidney stone still exists beyond 1 year after delivery.

Urological issues in pregnancy: A review for urologists

Urological issues in the pregnant patient present a unique clinical dilemma. These patients may be challenging to treat due to risks associated with medications and surgical procedures. This review aims to provide an update on the physiological changes and surgical risks in pregnancy. In addition, we review the approach for management of urolithiasis and urinary tract infections in pregnancy. Lastly, we highlight the importance of a multidisciplinary approach to placenta percreta, a condition not commonly addressed in urological education.

Safety and feasibility of percutaneous nephrolithotomy (PCNL) during pregnancy: A review of literature

OBJECTIVE

Management of nephrolithiasis during pregnancy can be challenging because of the potential risks to the mother and fetus. Diagnosis and treatment can be a dilemma owing to the anatomical and physiological changes, besides the limitation in the use of X-rays. The aim of this article was to identify any case series or case reports where percutaneous nephrolithotomy (PCNL) was used as a treatment modality for nephrolithiasis in pregnancy.

MATERIAL AND METHODS

A review of the literature was performed using Medline, EMBASE, CINAHL, and Scopus from 1990 to October 2019. A search was conducted using the following search terms: "urolithiasis," "renal stones," "stone disease," "kidney stones," "pregnancy," "pregnant," "percutaneous nephrolithotomy," "PNL," and "PCNL." The initial search strategy retrieved 52 articles, but after going through them, only 7 were suitable for inclusion in this review.

RESULTS

Overall, seven studies reported regarding 16 patients who underwent PCNL procedure during pregnancy. The patients were aged 18-34 years and had the procedure between 11 and 32 weeks of gestation. Most stones were in the renal pelvis or pelvic-ureteric junction and sized 8-40 mm, with the most common indication for the intervention being refractory pain. Most treatments used ultrasound guidance, and X-ray fluoroscopy was employed only in two cases. No complications occurred to the mother or fetus in any of the case reports, suggesting that PCNL is a safe and feasible treatment for patients with persistent symptoms when conservative treatment has failed.

CONCLUSION

All the reported cases of PCNL achieved stone-free status with no complications. Although PCNL has been evidenced to be safe, it must be performed by experienced endourologists after careful consultation with the obstetricians. Patient counseling and multidisciplinary team decision-making are paramount in such complex scenarios.

Stones in special situations

There are several special situations in which urinary lithiasis presents management challenges to the urologist. An in-depth knowledge of the pathophysiology, unique anatomy, and treatment options is crucial in order to maintain good health in these patients. In this review, we summarize the current literature on the management of the following scenarios: bladder stones, stones in bowel disease, during pregnancy, in association with renal anomalies, with skeletal deformities, in urinary diversions, and in children.

Renal colic during pregnancy: Diagnostic and therapeutic aspects. Literature review

Introduction

Renal colic during pregnancy is a rare urgency but is one of the most common non-obstetric reasons for hospital admission. The management often means a challenge for the urologist and gynecologist due to the complexity involved in preserving the maternal and fetal well-being.

Material and methods

We performed a literature search within the PubMed database. We found 65 related articles in English. We selected 36 for this review prioritizing publications in the last two decades.

Results

The anatomical and functional changes of the genitourinary system during pregnancy are well documented; also during pregnancy, there are several metabolic pro-lithogenic factors. The most common clinical presentation is flank pain accompanied by micro or macro hematuria. US provides data identifying renal obstruction shown by an increased renal resistance index. MRI allows differentiating the physiological dilatation from the pathological caused by an obstructive stone showing peripheral renal edema and renal enlargement. Low dose CT has been determined to be a safe and highly accurate imaging technique. Once the diagnosis is confirmed, the initial management of patients should be conservative. When conservative management fails the interventional treatment is mandatory, a urinary diversion of the obstructed renal unit either by a JJ stent or through a PCN catheter has to be done. The definitive management of the stone can be done in the postpartum or deferred ureteroscopy can be considered during pregnancy.

Conclusions

Renal colic during pregnancy is an uncommon urgency, so it is important for the urologist to know the management of this condition.

A best practice position statement on pregnancy in chronic kidney disease: the Italian Study Group on Kidney and Pregnancy

Pregnancy is increasingly undertaken in patients with chronic kidney disease (CKD) and, conversely, CKD is increasingly diagnosed in pregnancy: up to 3 % of pregnancies are estimated to be complicated by CKD. The heterogeneity of CKD (accounting for stage, hypertension and proteinuria) and the rarity of several kidney diseases make risk assessment difficult and therapeutic strategies are often based upon scattered experiences and small series. In this setting, the aim of this position statement of the Kidney and Pregnancy Study Group of the Italian Society of Nephrology is to review the literature, and discuss the experience in the clinical management of CKD in pregnancy. CKD is associated with an increased risk for adverse pregnancy-related outcomes since its early stage, also in the absence of hypertension and proteinuria, thus supporting the need for a multidisciplinary follow-up in all CKD patients. CKD stage, hypertension and proteinuria are interrelated, but they are also independent risk factors for adverse pregnancy-related outcomes. Among the different kidney diseases, patients with glomerulonephritis and immunologic diseases are at higher risk of developing or increasing proteinuria and hypertension, a picture often difficult to differentiate from preeclampsia. The risk is higher in active immunologic diseases, and in those cases that are detected or flare up during pregnancy. Referral to tertiary care centres for multidisciplinary follow-up and tailored approaches are warranted. The risk of maternal death is, almost exclusively, reported in systemic lupus erythematosus and vasculitis, which share with diabetic nephropathy an increased risk for perinatal death of the babies. Conversely, patients with kidney malformation, autosomal-dominant polycystic kidney disease, stone disease, and previous upper urinary tract infections are at higher risk for urinary tract infections, in turn associated with prematurity. No risk for malformations other than those related to familiar urinary tract malformations is reported in CKD patients, with the possible exception of diabetic nephropathy. Risks of worsening of the renal function are differently reported, but are higher in advanced CKD. Strict follow-up is needed, also to identify the best balance between maternal and foetal risks. The need for further multicentre studies is underlined.

Ureteral Stent Insertion in the Management of Renal Colic during Pregnancy

To determine an optimal invasive intervention for renal colic patients during pregnancy after conservative treatments have been found to be unhelpful. Among the available invasive interventions, we investigated the reliability of a ureteral stent insertion, which is considered the least invasive intervention during pregnancy. Between June 2006 and February 2015, a total of 826 pregnant patients came to the emergency room or urology outpatient department, and 39 of these patients had renal colic. The mean patient age was 30.49 years. In this retrospective cohort study, the charts of the patients were reviewed to collect data that included age, symptoms, the lateralities and locations of urolithiasis, trimester, pain following treatment and pregnancy complications. Based on ultrasonography diagnoses, 13 patients had urolithiasis, and 13 patients had hydronephrosis without definite echogenicity of the ureteral calculi. Conservative treatments were successful in 25 patients. Among these treatments, antibiotics were used in 15 patients, and the remaining patients received only hydration and analgesics without antibiotics. Several urological interventions were required in 14 patients. The most common intervention was ureteral stent insertion, which was performed in 13 patients to treat hydronephrosis or urolithiasis. The patients' pain was relieved following these interventions. Only one patient received percutaneous nephrostomy due to pyonephrosis. No pregnancy complications were noted. Ureteral stent insertion is regarded as a reliable and stable first-line urological intervention for pregnant patients with renal colic following conservative treatments. Ureteral stent insertion has been found to be equally effective and safe as percutaneous nephrostomy, which is associated with complications that include bleeding and dislocation, and the inconvenience of using external drainage system.

Stone disease in pregnancy: imaging-guided therapy

Renal colic is the most frequent nonobstetric cause for abdominal pain and subsequent hospitalization during pregnancy. The physio-anatomical changes in the urinary tract and the presence of the fetus may complicate the clinical presentation and management of nephrolithiasis. Ultrasound (US) is the primary radiological investigation of choice. Magnetic resonance urography (MRU) and low-dose computed tomography (CT) have to be considered as a second- and third-line test, respectively. If a study that uses ionizing radiation has to be performed, the radiation dose to the fetus should be as low as possible. The initial management of symptomatic ureteric stones is conservative during pregnancy. Intervention will be necessary in patients who do not respond to conservative measures. Therefore, it is crucial to obtain a prompt and accurate diagnosis to optimize the management of these patients. Teaching Points • In pregnancy, renal colic is the most frequent nonobstetric cause for abdominal pain and hospitalization. • Magnetic resonance urography should be considered when ultrasound is nondiagnostic. • Low-dose CT should be considered as a last-line test during pregnancy.

Renal stones in pregnancy

Diagnosis and treatment of renal stones during pregnancy is a complex problem. Risks to the fetus from ionising radiation and interventional procedures need to be balanced with optimising clinical care for the mother. Management of such patients requires a clear understanding of available options, with a multidisciplinary team approach. In this review, we discuss the role of different diagnostic tests including ultrasound, magnetic resonance urography, and computerized tomography. We also provide an update on recent developments in the treatment of renal stones during pregnancy. Expectant management remains first-line treatment. Where definitive treatment of the stone is required, new evidence suggests that ureteroscopic stone removal may be equally safe, and possibly better than traditional temporising procedures.

[Renal colic in pregnancy: series of 103 cases]

PURPOSE

To evaluate the management of renal colic in pregnant woman in our hospital.

MATERIAL AND METHODS

A retrospective study of 103 pregnant patients, hospitalized for back pain of renal colic type, associated or not with a urinary tract infection, between January 2005 and October 2010. Three groups of patients were identified from the initial clinical and paraclinical (ultrasound). Group I involved patients with dilatation of the renal cavities associated with septic syndrome, they received analgesic treatment and empiric antibiotic therapy. Group II involved patients with dilatation of the renal cavities isolated, without fever, they received only analgesic treatment. Group III involved patients without dilatation of the renal cavities, they received analgesic treatment and antibiotics in case of fever, and then another cause of pain was sought.

RESULTS

The renal colic was due to a stone in 19.4 % of cases. A urinary infection was associated in 28 % of patients. Ultrasond was sufficient to confirm the diagnosis in 96 % of cases. In 4 % of cases, MRI or low-dose CT were necessary. Therapeutic management based on analgesic treatment, associated with probabilistic antibiotherapy or adapted in case of documented infection, allowed sedation of pain in two-third of cases. In case of failure or signs of severity, the urinary diversion by a double J stent was efficient, without consequences on pregnancy issue. One stone was treated by ureteroscopy during pregnancy without complication.

CONCLUSION

The management of renal colic in pregnant woman based on ultrasound diagnosis, symptomatic treatment and urinary diversion by double J stent in case of failure therefore seemed quite sure on mother and fetus.

Kidney stones and pregnancy

Kidney stones are common and do not spare the pregnant population. Although a simple stone event is usually straightforward in the general population, it is complex during pregnancy. Acute nephrolithiasis is associated with a unique set of complications during pregnancy and, because of imaging limitations, diagnosis is challenging. Multidisciplinary care is the key in proper management decisions. The pathophysiology of kidney stone formation in the pregnant state is also unique. Herein, we discuss the complexity of kidney stones and pregnancy.

Double-J ureteric stenting in pregnancy: A single-centre experience from Iraq

OBJECTIVES

To evaluate the safety and effectiveness of ureteric stenting with a JJ stent in pregnant women, to relieve renal obstruction and intractable flank pain.

PATIENTS AND METHODS

All pregnant patients presenting with intractable flank pain, with or without complications, to a tertiary national teaching hospital in Kurdistan/Iraq, and necessitating ureteric stenting with a JJ stent, were prospectively assessed for this study between March 2008 and March 2010.

RESULTS

In all, 30 pregnant patients presented with intractable flank pain necessitating JJ ureteric stenting during the 25 months. Intractable flank pain (23 patients, 77%) was the most common indication for ureteric stenting, followed by flank pain with clinical sepsis (six, 20%). All pregnant women had hydronephrosis on ultrasonography (US), and 12 (40%) had evidence of coexisting renal stones on US. All ureteric stents were inserted successfully. The mean (range) indwelling time was 47.4 (3-224) days. Radiologically, 14 (47%) and 15 (50%) had complete resolution of the hydronephrosis on follow-up US in late pregnancy and in the early postnatal period, respectively. Two-thirds of patients had a clinical improvement immediately (15, 50%) and soon after (five, 17%) surgery. Stent encrustation (three, 10%), stent migration (three, 10%) and stent irritation (five, 17%) were reported as complications. The post-natal evaluation confirmed that half the patients had urinary calculus disease.

CONCLUSION

Ureteric stenting during pregnancy can be safe, with no intraoperative imaging and even under local anaesthesia. It provides good symptom relief and has a low complication rate. We therefore advocate it as a first-line treatment in pregnant women with therapy-resistant flank pain.

Acute pyelonephritis in pregnancy: a retrospective descriptive hospital based-study

Introduction. Pyelonephritis is a common complication of pregnancy. It is also exacerbated by immunocompromised states and also the sickle cell gene. We reviewed this condition in Jamaican women. Method. We did a six year hospital database docket review. We found 102 confirmed cases. Results. Pyelonephritis was found in 0.7% of deliveries. The mean maternal age was 24 ± 5.83 years with 51% primiparity. Most (58.8%) occurred in the second trimester. The main symptoms were loin pain (96.2%) and abdominal pain (84.6%). It was more common on the right side in 67% of cases. On urinalysis, 81.4% had pyuria. The commonest organism was Escherichia coli, in 61% of cases. Patients given Antibiotics prior to admission had quicker resolution, P < 0.02. Haemoglobin S was found in 16% cases (general population 10%; P = 0.002). However diabetes was only found in 1.3% cases (1.5% expected). 61.3% had positive urine culture after treatment showed that 61.3% and 25% had recurrent pyelonephritis. Complications included 32% threatened preterm labour and 17% preterm delivery. About 6% of neonates had intrauterine growth restriction. There were no ICU admissions and no deaths. Conclusion. Early recognition and treatment of pyelonephritis result in good outcome. The condition is more prevalent in patients with the sickle cell gene and recurrence is high.

Clinical effectiveness protocols for imaging in the management of ureteral calculous disease: AUA technology assessment

PURPOSE

This technology assessment addresses the optimal use of imaging in the evaluation and treatment of patients with suspected or documented ureteral stones.

MATERIALS AND METHODS

A comprehensive literature search addressing 4 guiding questions was performed for full text in English articles published between January 1990 and July 2011. The search focused on major subtopics associated with the imaging of ureteral calculi, and included specific imaging modalities used in the diagnosis and management of ureteral calculous disease such as unenhanced (noncontrast) computerized tomography, conventional radiography, ultrasound, excretory urography, magnetic resonance imaging and nuclear medicine studies. Protocols (in the form of decision tree algorithms) were developed based on this literature review and in some instances on panel opinion. The 4 questions addressed were 1) What imaging study should be performed for suspected ureteral calculous disease? 2) What information should be obtained? 3) After diagnosis of a ureteral calculus, what followup imaging should be used? 4) After treatment of a ureteral calculus, what followup imaging studies should be obtained?

RESULTS

Based on these protocols, noncontrast computerized tomography is recommended to establish the diagnosis in most cases, with a low energy protocol advocated if body habitus is favorable. Conventional radiography and ultrasound are endorsed for monitoring the passage of most radiopaque stones as well as for most patients undergoing stone removal. Other studies may be indicated based on imaging findings, and patient, stone and clinical factors.

CONCLUSIONS

The protocols generated assist the clinician in establishing the diagnosis of ureteral calculous disease, monitoring stone passage and following patients after treatment. The protocols take into account not only clinical effectiveness but also cost-effectiveness and risk/harm associated with the various imaging modalities.

Imaging of pregnant and lactating patients: part 2, evidence-based review and recommendations

OBJECTIVE

The objectives of this article are to discuss the current evidence-based recommendations regarding the use of diagnostic imaging in the evaluation of pulmonary embolism, appendicitis, urolithiasis, and cholelithiasis during pregnancy.

CONCLUSION

Diagnostic imaging should be performed during pregnancy only with an understanding of the maternal and fetal risks and benefits, the comparative advantages of different modalities, and the unique anatomic and physiologic issues associated with pregnancy.

Half Fourier single-shot turbo spin-echo magnetic resonance urography for the evaluation of suspected renal colic in pregnancy

OBJECTIVE

To report our experience with magnetic resonance urography (MRU) in pregnant women suspected of having obstructing upper tract calculi. The diagnosis of an upper tract calculus in the pregnant woman can be challenging. Recent evidence suggests that MRU can be used to effectively evaluate renal colic.

METHODS

From 2008-2011, 9 pregnant women were referred for evaluation of suspected renal colic caused by an obstructing upper tract stone. All patients underwent MRU with a half Fourier single-shot turbo spin-echo (HASTE) protocol. Medical records and imaging studies were reviewed for demographic and clinical data as well as outcome measures.

RESULTS

The mean age of the subjects was 25 years (range 20-34); average gestational age of the fetus was 23 weeks (range 9-36). In all cases, a renal ultrasound was the initial imaging study obtained, with nondiagnostic findings. HASTE MRU detected 4 ureteral stones and 4 cases of physiological hydronephrosis of pregnancy. In one case, interpretation of the MRU was limited as a result of patient motion. Of the patients with obstructing stones, 1 required endourologic management during her pregnancy and 3 were followed conservatively. No adverse events related to MRU occurred.

CONCLUSION

HASTE MRU is an informative imaging study for pregnant women with suspected upper tract stone disease. Information gathered from this study augments that gained from alternative modalities, and aids in medical decision-making. The lack of ionizing radiation exposure, coupled with the capture of detailed anatomic imaging, makes HASTE MRU a particularly useful study in this setting.

Nontraumatic abdominal pain in pregnancy: imaging considerations for a multiorgan system problem

Nontraumatic abdominal pain in the pregnant patient can present a clinician with a variety of diagnostic possibilities. The overlap between signs and symptoms expected in normal pregnancy and these many pathologic possibilities does little to help focus the clinician's diagnostic efforts. Fear of ionizing radiation's effects on the fetus has driven efforts to refine medical imaging algorithms in such a way as to attempt to eliminate its use at all cost. In today's world, we are nearly there. In this review the differential diagnosis of nontraumatic abdominal pain in the pregnant patient will be explored. Of note is the recurring theme that much of what can be done today with regard to diagnostic imaging, both in general and with regard to this specific subset of patients, centers on the use of the non-ionizing modalities of ultrasound and magnetic resonance imaging.

Nephrolithiasis: evaluation and management

Nephrolithiasis is a major cause of morbidity involving the urinary tract. The prevalence of this disease in the United States has increased from 3.8% in the 1970s to 5.2% in the 1990s. There were nearly two million physician-office visits for nephrolithiasis in the year 2000, with estimated annual costs totaling $2 billion. New information has become available on the clinical presentation, epidemiologic risk factors, evaluative approach, and outcome of various therapeutic strategies. In this report, we will review the epidemiology and mechanisms of kidney-stone formation and outline management aimed at preventing recurrences. Improved awareness and education in both the general population and among health-care providers about these modifiable risk factors has the potential to improve general health and decrease morbidity and mortality secondary to renal-stone disease.

Stone formation and pregnancy: pathophysiological insights gained from morphoconstitutional stone analysis

PURPOSE

We examined whether stone composition in pregnant women reflects peculiar pathophysiological conditions.

MATERIALS AND METHODS

We analyzed in detail the composition of stones from 244 pregnant women 17 to 44 years old and from 5,712 nonpregnant women in the same age range, as recorded between January 1991 and December 2007. Clinical features were also recorded. All stones were analyzed by morphological examination coupled with infrared spectroscopy. The 2 patient groups were compared by clinical and biochemical characteristics.

RESULTS

Stone episodes in pregnant women manifested mainly in trimesters 2 and 3 (39% and 46%, respectively). Spontaneous passage was noted in 81% of pregnant vs 47% of nonpregnant women (p <0.0001). Calcium phosphate, mainly in the form of carbapatite, was the main stone component in 65.6% of pregnant vs 31.4% of nonpregnant women (p <0.0001). Octacalcium phosphate pentahydrate, a transition phase in calcium phosphate stone formation, was found in a 5-fold higher proportion in carbapatite stones in pregnant than in nonpregnant women, a finding also suggesting recent stone formation during pregnancy.

CONCLUSIONS

The composition of stones manifesting during pregnancy clearly differs from that of stones formed in nonpregnant women of childbearing age, suggesting a different pathophysiology specific to the pregnant state. In view of the pH dependency of calcium phosphate stones factors that increase the physiological elevation in maternal urinary calcium excretion and pH are likely to have a role in the preferential formation of calcium phosphate stones during pregnancy.

Semirigid ureteroscopy and pneumatic lithotripsy as definitive management of obstructive ureteral calculi during pregnancy

OBJECTIVES

To assess the results of semirigid ureteroscopy and intracorporeal pneumatic lithotripsy as a definitive treatment option for women presenting with obstructive ureteral calculi during pregnancy.

METHODS

A retrospective analysis was performed of 19 pregnant patients referred to our tertiary care center with ureteral obstruction necessitating surgical intervention from 1997 to 2007. The mean patient age was 22 years (range 18-27), and the mean gestation period was 20 weeks (range 14-34). Of the 19 patients, 21% were febrile, 32% had positive urine cultures, and 63% had pyuria and microscopic hematuria. Abdominal ultrasonography was the principle diagnostic test used. Six patients had history of renal stones before conception. The mean stone size was 11 mm, (range 8-18). Of the 19 patients, 58% had stones located in the proximal and 42% in the distal ureter. The stones were fragmented using a Swiss pneumatic lithoclast through a 6.9F/8F semirigid ureteroscope with the patient under general anesthesia. None of the patients underwent limited intravenous urography or computed tomography except for 1, who underwent plain x-ray of the kidneys, ureters, and bladder.

RESULTS

All patients had obstruction due to the ureteral calculi, and 79% patients had complete fragmentation of the calculi by ureteroscopy as the primary treatment. Of the 19 patients, 63% required ureteral stent insertion per operatively. No complications related to the procedure itself or the general anesthesia were recorded, and all patients completed the full term of pregnancy.

CONCLUSIONS

The results of our study have shown that semirigid ureteroscopy to diagnose ureteral calculi and treat them with intracorporeal pneumatic lithotripsy and ureteral stent insertion, as indicated, is the most efficient and definitive treatment modality in expectant women.

Imaging in diagnosis, treatment, and follow-up of stone patients

Imaging has an essential role in the diagnosis, management, and follow-up of patients with stone disease. A variety of imaging modalities are available to the practicing urologist, including conventional radiography (KUB), intravenous urography (IVU), ultrasound (US), magnetic resonance urography, and computed tomography (CT) scans, each with its advantages and limitations. Traditionally, IVU was considered the gold standard for diagnosing renal calculi, but this modality has largely been replaced by unenhanced spiral CT scans at most centers. Renal US is recommended as the initial imaging modality for suspected renal colic in pregnant women and children, but recent literature suggests that a low-dose CT scan may be safe in pregnancy. Intraoperative imaging by fluoroscopy or US plays a large part in assisting the urologist with the surgical intervention chosen for the individual stone patient. Posttreatment imaging of stone patients is recommended to ensure complete fragmentation and stone clearance. Plain radiography is suggested for the follow-up of radiopaque stones, with ultrasound and limited IVU reserved for the follow-up of radiolucent stones to minimize cumulative radiation exposure from repeated CT scans. Patients with asymptomatic calyceal stones who prefer an observational approach should have a yearly KUB to monitor progression of stone burden. Current research has been aimed toward the development of a micro-CT scan and coherent-scatter analysis to determine stone composition in vivo. This may have a significant impact on the future clinical management of renal calculi by facilitating selection of the most appropriate surgical intervention based on stone composition at the time of presentation.

Management of urinary calculi in pregnancy: a review

Nephrolithiasis during pregnancy can represent a clinical dilemma because of potential risks to both mother and fetus. While the incidence of symptomatic nephrolithiasis during pregnancy varies between 1 in 244 to 1 in 2000 pregnancies, the actual incidence is likely to be higher. A significant proportion of patients with asymptomatic renal calculi are detected incidentally in the nonpregnant population compared with pregnant women. Factors that contribute to the diagnostic challenges include anatomic and physiologic changes to the female urinary tract during pregnancy and the limitations on the use of ionizing radiation. The treatment of such patients requires a multidisciplinary team approach involving the urologist, obstetrician, and radiologist. The potential hazards of intervention (either surgical or medical) and anesthesia need to be considered carefully.

Low-dose computed tomography for the evaluation of flank pain in the pregnant population

BACKGROUND

Evaluation of the pregnant patient with suspected renal colic is complex. Fetal irradiation concerns have traditionally prohibited the use of CT in this population. We report our institution's experience using low-dose CT in the evaluation of pregnant patients with refractory flank pain.

PATIENTS AND METHODS

A retrospective review of all patients who underwent low-dose CT evaluation of the urinary tract for suspected urinary tract stones was performed. Data obtained included gestational age, urinalysis and ultrasonography results, CT findings, and calculated fetal radiation exposure.

RESULTS

Between April 2004 and December 2006, 20 patients with an average gestational age of 26.5 weeks presented to our institution with acute, refractory flank pain consistent with a diagnosis of urolithiasis. All patients underwent renal ultrasonographic evaluation before unenhanced CT of the abdomen and pelvis using a low-dose protocol. The average radiation exposure was 705.75 mrads (range 210-1372; SD +/- 338.66 mrads). Of the 20 patients, CT demonstrated urinary stones (1-12 mm) in 13. Of those patients with documented stones, 4 were treated conservatively, 2 underwent intrapartum stent placement, 5 had ureteroscopy with stone extraction, and 2 were treated postpartum.

CONCLUSION

Low-dose CT is highly sensitive and specific for the detection of urinary calculi in the pregnant population. CT confers a low risk of fetal harm and can improve patient care when used judiciously.

Acute Flank Pain Secondary to Urolithiasis: Radiologic Evaluation and Alternate Diagnoses

This article discusses the radiologic management of the patient who has acute flank pain. It describes the evolution of radiologic imaging in patients who present with acute symptoms caused by suspected urolithiasis, the advantages of unenhanced helical CT and the limitations of abdominal radiography, intravenous urography, and ultrasonography in this setting, and the alternative diagnoses encountered within the urinary tract, abdomen, and pelvis.

Management of Symptomatic Urolithiasis During Pregnancy

Urinary calculi during pregnancy present not only a diagnostic challenge but also a management dilemma. In this retrospective study, we describe our experience with diagnosis and management of symptomatic urolithiasis in pregnant women. A total of 18 pregnant women were treated for urolithiasis at the Department of Urology, Kaohsiung Municipal Hsiao-Kang Hospital, between 1999 and 2004. The incidence of symptomatic urolithiasis during pregnancy was 0.35%. Of the 20 stones found, nine were on the right side and 11 were on the left, and two patients had bilateral urinary stones. Most urolithiasis cases during pregnancy (55.5%) occurred in the third trimester. Flank pain (94.4%) was the most common clinical presentation. Conservative management was successful in 10 patients until the end of pregnancy and then definite treatment was performed. In four patients, a double-J stent was inserted successfully for persistent pain. In three cases with persistent pain, failure of double-J stent placement was treated with ureteroscopic lithotripsy under epidural anesthesia. One patient received percutaneous nephrostomy for persistent renal colic and pyonephrosis. Ultrasonographic evaluation of pregnant women with suspected renal colic is a reasonable diagnostic procedure. Ureteroscopy is another choice when conservative treatment fails.

Acute renal failure in pregnancy

OBJECTIVES

To provide an evidence-based, up-to-date review of the literature regarding the assessment and management of acute renal failure that may affect women during pregnancy and the postpartum period.

DESIGN

A review of the current literature was performed.

RESULTS

Acute renal failure is a rare complication of pregnancy but is associated with significant morbidity and mortality. Management requires knowledge of the renal physiologic changes occurring in pregnancy and the relevant diagnoses, both pregnancy-specific and those that may coincidentally occur with pregnancy. In addition, fetal effects must be taken into consideration.

CONCLUSIONS

Ideal care for women with acute renal failure in pregnancy or postpartum requires a multidisciplinary approach that may include maternal-fetal medicine, critical care medicine, nephrology, and neonatology specialists.

Urinary tract infections in pregnancy

Urinary tract infections occur commonly in pregnancy. Bacterial colonization may occur in the lower and upper urinary tract, and is facilitated by the normal physiologic changes of pregnancy. Asymptomatic bacteriuria, cystitis, and pyelonephritis each pose a serious threat to the mother and fetus. Optimal treatment regimens and preventative strategies continue to be investigated.

[Nephrolithiasis and primary hyperarathyroidism in pregnancy]

Diagnosis of hyperparathyroidism is unusual during pregnancy. The presence of a renal stone is a very exceptional finding. Hypercalcemia is often revealed by standard blood tests. We present here a clinical case of renal nephretic colic occurring during the third trimester of a fourth pregnancy. Our investigations led to the diagnosis of primary hyperparathyroidism which was successfully treated. Hyperparathyroidism during pregnancy is associated with a high incidence of fetal and maternal complications, essentially neonatal hypocalcemia. In utero death is rare but has been reported. Calcium metabolism during pregnancy is dependent on PTHrp. The surgical option is usually taken during the second trimester but can only be proposed during the third trimester in the event of medically resistant hypercalcemia.

Evaluation of the patient with flank pain and possible ureteral calculus

Flank pain due to urolithiasis is a common problem in patients presenting to emergency departments. Radiology plays a vital role in the work-up of these patients. Many modalities can be used, including ultrasonography, nuclear medicine, and the traditionally used techniques of intravenous urography and conventional radiography. The development of nonenhanced computed tomography (CT) (single- or multi-detector row helical) has provided a means to enable detection and characterization of urolithiasis with unprecedented sensitivity, specificity, and accuracy while yielding important information for treatment planning, including the size and location of calculi. This technique can also help detect causes for flank pain outside the genitourinary tract. However, close attention must be paid to all aspects of the CT study to prevent misdiagnoses.

Ureteroscopy as a first-line intervention for ureteral calculi in pregnancy

BACKGROUND AND PURPOSE

Renal colic in pregnancy presents a diagnostic and therapeutic challenge. When conservative therapy fails or is not indicated, temporary measures such as ureteral stenting are often chosen as a first-line intervention, postponing definitive management until after delivery. We propose that advances in endoscopic equipment and anesthesia techniques dictate a more definitive strategy.

PATIENTS AND METHODS

A retrospective analysis was performed on 10 consecutive pregnant patients presenting with renal colic necessitating intervention between April 1998 and April 2000. The mean patient age was 23 (range 17-31) years. One patient presented during the first trimester, six in the second, and three in the third. Four of the patients had a history of stone disease. All patients had flank pain at presentation, six on the left side and four on the right. Hematuria, fever, and nausea were present in eight, one and two patients, respectively.

RESULTS

Ultrasound scanning was performed in all patients and showed a low sensitivity (28.5%) when compared with intraoperative findings. Ureteroscopy (rigid and/or flexible) was performed as a first-line intervention in six patients, in two of whom no stone was found. Percutaneous nephrolithotomy was carried out in one patient presenting with a nephrostomy tube. Double-J stents were placed in only three patients with specific indications, namely urinary infection, late gestational phase, and difficult ureteroscopy secondary to a narrow ureter. No obstetric or urologic complications were noted. The mean size of the stones retrieved in seven patients was 7 mm.

CONCLUSIONS

Ureteroscopy may be considered a safe and effective first-line definitive therapeutic option in pregnant patients requiring intervention for stone disease.