Renal outcomes of simultaneous liver–kidney transplantation compared to liver transplant alone for candidates with renal dysfunction

It is unclear whether a concomitant kidney transplant grants survival benefit to liver transplant (LT) candidates with renal dysfunction (RD). We retrospectively studied LT candidates without RD (n = 714) and LT candidates with RD who underwent either liver transplant alone (RD‐LTA; n = 103) or simultaneous liver–kidney transplant (RD‐SLKT; n = 68). RD was defined as renal replacement therapy (RRT) requirement or modification of diet in renal disease (MDRD)–glomerular filtration rate (GFR) <25 mL/min/1.73 m². RD‐LTAs had worse one‐yr post‐transplant survival compared to RD‐SLKTs (79.6% vs. 91.2%, p = 0.05). However, RD‐LTA recipients more often had hepatitis C (60.2% vs. 41.2%, p = 0.004) and more severe liver disease (MELD 37.9 ± 8.1 vs. 32.7 ± 9.1, p = 0.0001). Twenty RD‐LTA recipients died in the first post‐transplant year. Evaluation of the cause and timing of death relative to native renal recovery revealed that only four RD‐LTA recipients might have derived survival benefit from RD‐SLKT. Overall, 87% of RD‐LTA patients recovered renal function within one month of transplant. One yr after RD‐LTA or RD‐SLKT, serum creatinine (1.5 ± 1.2 mg/dL vs. 1.4 ± 0.5 mg/dL, p = 0.63) and prevalence of stage 4 or 5 chronic kidney disease (CKD; 5.9% vs. 6.8%, p = 0.11) were comparable. Our series provides little evidence that RD‐SLKT would have yielded substantial short‐term survival benefit to RD‐LTA recipients.     

Predictive Value of Dobutamine Stress Echocardiography for Coronary Artery Disease Detection in Liver Transplant Candidates

Patients with obstructive coronary artery disease (CAD) undergoing orthotopic liver transplantation (OLT) are at increased risk of poor outcomes. The accuracy of dobutamine stress echocardiography (DSE) to detect obstructive CAD is not well established in this population. We retrospectively identified patients with end-stage liver disease who underwent both DSE and coronary angiography as part of risk stratification prior to OLT. One hundred and five patients had both DSE and angiography, of whom 14 had known CAD and 27 failed to reach target heart rate during DSE. Among the remaining 64 patients (45 men; average age 61 ± 8 years) DSE had a low sensitivity (13%), high specificity (85%), low positive predictive value (PPV) (22%) and intermediate negative predictive value (NPV) (75%) for obstructive CAD. DSE as a screening test for obstructive CAD in OLT candidates has a poor sensitivity. The frequent chronotropic incompetence and low sensitivity in patients who achieve target heart rate, even in those with multiple cardiovascular disease risk factors, suggest that alternative or additional methods of risk stratification are necessary.     

Risk stratification of myocardial injury after liver transplantation in patients with computed tomographic coronary angiography–diagnosed coronary artery disease

We aimed to determine if the severity of computed tomographic coronary angiography (CTCA)–diagnosed coronary artery disease (CAD) is associated with postliver transplantation (LT) myocardial infarction (MI) within 30 days and early mortality. We retrospectively evaluated 2118 consecutive patients who underwent CAD screening using CTCA. Post‐LT type‐2 MI, elicited by oxygen supply‐and‐demand mismatch within a month after LT, was assessed according to the severity of CTCA‐diagnosed CAD. Obstructive CAD (>50% narrowing, 9.2% prevalence) was identified in 21.7% of patients with 3 or more known CAD risk factors of the American Heart Association. Post‐LT MI occurred in 60 (2.8%) of total patients in whom 90‐day mortality rate was 16.7%. Rates of post‐LT MI were 2.1%, 3.1%, 3.4%, 4.3%, and 21.4% for normal, nonobstructive CAD, and 1‐, 2‐, and 3‐vessel obstructive CAD, respectively. Two‐vessel or 3‐vessel obstructive CAD showed a 4.9‐fold higher post‐LT MI risk compared to normal coronary vessels. The sensitivity and negative predictive value of obstructive CAD in detecting post‐LT MI were, respectively, 20% and 97.5%. In conclusion, negative CTCA finding in suspected patients can successfully exclude post‐LT MI, whereas proceeding with invasive angiography is needed to further risk‐stratify in patients with significant CTCA‐diagnosed CAD. Prognostic role of CTCA in predicting post‐LT MI needs further research.     

Screening colonoscopy in liver transplant candidates: risks and findings

The indication for mandatory screening colonoscopies in liver transplant candidates is controversial. Since the introduction of MELD‐based allocation, patients with advanced liver disease and often severe comorbidities are prioritized for liver transplantation (LT). This study evaluated safety and outcome of colonoscopy in this high‐risk patient group. During a two‐yr period, we performed 243 colonoscopies in potential LT candidates. Endoscopic findings were registered in a standardized form, and correlations with biochemical or clinical parameters were analyzed using Mann–Whitney U‐test and chi‐square test. Only 57 patients (23.5%) had an endoscopically normal colon. Main findings were polyps (45.7%), hypertensive colopathy (24.3%), diverticulosis (21%), rectal varices (19.8%), and hemorrhoids (13.6%). In 21% of all patients, the removed polyps were diagnosed as adenomas. The prevalence of neoplastic polyps increased significantly with age: 13.6% (patients <50 yr) vs. 25% (patients ≥50 yr) (p = 0.03). Advanced neoplasia was found only in patients older than 40 yr. No major complications were observed; post‐interventional hemorrhage was observed in 1.7% and controlled by clipping or injection therapy. In conclusion, lower gastrointestinal endoscopy is safe and effective in LT candidates. Due to the age dependency of neoplastic polyps, a screening colonoscopy should be performed in LT candidates older than 40 yr or with symptoms or additional risk factors.     

Potential clinical impact of reporting breast arterial calcifications on screening mammograms in women without known coronary artery disease

Cardiovascular disease remains a leading cause of death in women. 10-year likelihood for a cardiovascular event is determined by the American College of Cardiology Atherosclerotic Cardiovascular disease risk score calculator (ASVCD); however, this does not encompass risk factors unique to women. Breast arterial calcifications (BAC) detected on screening mammography may serve as a proxy for coronary atherosclerosis (CAC) in women. Our purpose was to investigate the correlation between BAC and CAC on imaging in women without a diagnosis of atherosclerosis to determine the potential clinical impact. Retrospective review was performed on a cohort of females evaluated by internists at our institution in 2019. Study patients had a screening mammogram within 1 year of a noncardiac chest CT. Clinical data were collected to determine ASCVD risk score. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of BAC in detecting CAC were determined. 222 women met inclusion criteria, ranging from 41 to 77 years of age, among which 25% (56/222) had BAC. 84% (47/56) of women with BAC had CAC on CT, yielding a sensitivity, specificity, PPV, and NPV of 51%, 93%, 84%, and 72%, respectively. Of the 47 patients who had both BAC and CAC, 66% had an unknown or low-to-borderline ASCVD score. Women with BACs have a high specificity for CAC. The reporting of BACs should prompt clinicians to risk stratify women for atherosclerotic disease. These women may otherwise be undetected by conventional risk calculators.     

Combined off-pump coronary bypass grafting without heparin and liver transplantation: A novel approach to a complex dilemma

Cardiac disease is a leading cause of early mortality for patients undergoing liver transplantation (LT), and severe coronary artery disease (CAD) is usually considered a contraindication for LT in patients with cirrhosis. Incidence of CAD in LT candidates has increased in recent years. While stable patients might be candidates for percutaneous interventions, patients with decompensated liver failure, or critical coronary lesions present a therapeutic challenge, and are often not considered candidates for LT. We present the case of a 60 year old male patient with decompensated liver failure, and critical CAD, who received successful combined off-pump coronary bypass grafting without heparin and LT using ex vivo normothermic liver perfusion machine. This approach represents a novel strategy to offer LT to this very selective group of patients.     

The Role of Coronary Calcium Score in the Risk Assessment of Liver Transplant Candidates

Background

Coronary artery disease (CAD) is a common cause of morbidity and mortality in liver transplant (LT) recipients. To date there is no consensus on the preferred screening tests to detect CAD in the pre-LT population. Therefore the aim of this study was to: 1) evaluate the utility of a noninvasive tool (cardiac computerized tomography [CT] scan); and 2) determine the prevalence of CAD in low-risk LT candidates.

Methods

Using our transplant database we identified all LT candidates classified as low risk for CAD. All low-risk candidates underwent cardiac CT scan for coronary calcium score (CCS) estimation. Those with CCS >100 underwent coronary angiogram, and those with <100 underwent stress test and if stress test was positive then coronary angiography was performed. The Agatston calcium score was classified as: normal (0), mild (1–100), moderate (101–400), severe (401–1,000), or extensive (>1,000).

Results

Eighty-five LT candidates were classified as low risk and underwent cardiac CT scan. The mean calcium score was 325 (range, 0–3,707). In our study cohort, 21% had normal CCS score, 43% mild, 13% moderate, 11% severe, and 12% extensive. A calcium score >400 was significantly associated with CAD on angiography (P = .02). Although male sex was significantly associated with the presence of CAD (P = .006), there was no correlation with age, ethnicity, liver diagnosis, or Model for End-Stage Liver Disease score.

Conclusions

Prevalence of asymptomatic CAD in this low-risk population is relatively high. Cardiac CT is well tolerated and is a useful noninvasive screening tool in LT candidates. Future studies to determine its utility as a prognostic tool after LT will be invaluable.     

Negative outcomes after liver transplantation in patients with alcoholic liver disease beyond the fifth post‐transplant year

Although up to 50% of patients with alcoholic liver disease (ALD) resume alcohol consumption after liver transplantation (LT), numerous studies indicate that long‐term results are not compromised. This study focused on evaluating the impact of ALD on outcomes up to and beyond the fifth year after LT. Among the 432 primary LT recipients included in this study, 97 underwent transplantation for ALD. Alcohol relapse rate at 10 yr was 33.5%, with younger recipient age being the only independent predictor (p = 0.019). Survival of patients with ALD (77.0%) was similar to those without (79.0%) up to the fifth post‐transplant year (p = 0.655) but worse during the five subsequent years among the five‐yr survivors (70.6% vs. 92.9%; p = 0.002). ALD was an independent risk factor for poorer survival beyond the fifth post‐transplant year (p = 0.049), but not earlier (p = 0.717). Conversely, alcohol relapse increased the risk of death only during the first five post‐transplant years (p = 0.039). There were no significant differences regarding graft failure incidence between ALD and non‐ALD recipients up to the fifth post‐transplant year (7.3% vs. 11.6%; p = 0.255) and beyond (12.9% vs. 5.0%; p = 0.126). In conclusion, pre‐transplant diagnosis of ALD yields negative effects on post‐transplant outcomes beyond the fifth post‐transplant year, not attributable to recidivism.     

Noninvasive estimation of pulmonary vascular resistance improves portopulmonary hypertension screening in liver transplant candidates

Despite limitations in sensitivity and specificity, estimation of the pulmonary artery systolic pressure (ePASP) on echocardiography is used for portopulmonary hypertension (PoPH) screening in liver transplant (LT) candidates. We proposed that alternative echocardiographic models, such as estimated pulmonary vascular resistance (ePVR), may provide improved testing characteristics in PoPH screening. In a retrospective analysis of 100 LT candidates, we found that the formula ePVR = ePASP/VTI_RVOT + 3 if MSN (VTI_RVOT = right ventricular outflow tract time velocity integral; MSN = mid‐systolic notching of the VTI_RVOT Doppler signal) significantly improves accuracy of PoPH screening compared to ePASP. We determined the optimal ePVR cutoff for PoPH screening to be 2.76 Wood units, as this cutoff provided 100% sensitivity and 73% specificity in screening for clinically significant PoPH. Comparatively, ePASP at a cutoff of 40 mm Hg provided 91% sensitivity and 48% specificity. We devised a new screening algorithm based on the use of ePVR at intermediate ePASP values (35‐54 mm Hg), and we confirmed the testing characteristics of this algorithm in a separate validation cohort of 50 LT candidates. In screening LT candidates for PoPH, the ePASP lacks accuracy, leading to unnecessary RHCs and undiagnosed cases of PoPH. A screening algorithm which incorporates the ePVR may be more reliable.     

Presence of any degree of coronary artery disease among liver transplant candidates is associated with increased rate of post-transplant major adverse cardiac events

The impact of coronary artery disease (CAD) among liver transplant candidates (LTC) on post-LT clinical outcomes remains unclear. The aim of this study is to determine association of presence and severity of CAD on post-LT major adverse cardiac events (MACE) including cardiac-associated mortality. We conducted a retrospective cohort analysis of 231 patients who underwent diagnostic coronary angiogram (DCA) during their LT evaluation at a tertiary medical center from 2012-2017. Patients were analyzed based on degree of CAD (no CAD, non-obstructive CAD [< 50% stenosis], obstructive CAD [≥50% stenosis]) per DCA results. MACE were noted at 30 days, 1 year, 3 years, and 5 years post-LT, and Kaplan-Meier curves were used to determine post-LT MACE-free probability. LTC with any CAD, including non-obstructive CAD, had lower MACE-free probability at all post-LT time points (0.94 vs 0.65 at 30 days, P = .001; 0.87 vs 0.59 at 1 year, P = .002; 0.87 vs 0.41 at 3 years, P < .001; 0.87 vs 0.37 at 5 years, P < .001). Identification of and medical intervention for non-obstructive CAD should be considered in all LTC, though further studies are necessary to determine optimal medical interventions to mitigate MACE risk in this cohort.     

Discovery and validation of a novel blood‐based molecular biomarker of rejection following liver transplantation

Noninvasive biomarker profiles of acute rejection (AR) could affect the management of liver transplant (LT) recipients. Peripheral blood was collected following LT for discovery (Northwestern University [NU]) and validation (National Institute of Allergy and Infectious Diseases Clinical Trials in Organ Transplantation [CTOT]‐14 study). Blood gene profiling was paired with biopsies showing AR or ADNR (acute dysfunction no rejection) as well as stable graft function samples (Transplant eXcellent—TX). CTOT‐14 subjects had serial collections prior to AR, ADNR, TX, and after AR treatment. NU cohort gene expression (46 AR, 45 TX) was analyzed using random forest models to generate a classifier training set (36 gene probe) distinguishing AR vs TX (area under the curve 0.92). The algorithm and threshold were locked and tested on the CTOT‐14 validation cohort (14 AR, 50 TX), yielding an accuracy of 0.77, sensitivity 0.57, specificity 0.82, positive predictive value (PPV) 0.47, and negative predictive value (NPV) 0.87 for AR vs TX. The probability score line slopes were positive preceding AR, and negative preceding TX and non‐AR (TX + ADNR) (P ≤ .001) and following AR treatment. In conclusion, we have developed a blood biomarker diagnostic for AR that can be detected prior to AR‐associated graft injury as well a normal graft function (non‐AR). Further studies are needed to evaluate its utility in precision‐guided immunosuppression optimization following LT.     

Comparing 10‐yr renal outcomes in deceased donor and living donor liver transplants

Few studies have explored whether the type of LT, deceased donor LT (DDLT) or living donor LT (LDLT), impacts long‐term renal outcomes. We performed a retrospective analysis of 220 LT recipients at our institution to study their renal outcomes at 10 yr. Exclusion criteria were age ≤ 18 yr, graft survival ≤6 months, and multiorgan transplants; 108 DDLTs and 62 LDLTs were eligible. At baseline, DDLTs had a lower eGFR than LDLTs and 10.2% of DDLTs were on dialysis as compared to 0% of LDLTs. At 10 yr, seven DDLT and three LDLT recipients required dialysis or renal transplant (p = 0.75). In recipients with graft survival >6 months, DDLTs had a slower decline in eGFR as compared to LDLTs (p < 0.01). Among LDLTs, the decline in eGFR continued over the entire 10‐yr period, whereas among DDLTs, the decline in eGFR slowed significantly after six months (p = 0.01). This difference between the two groups was not seen among patients in the highest quartile of baseline eGFR. Patient survival and graft survival were similar. In conclusion, the incidence of end‐stage renal disease was similar in both DDLT and LDLT patients, but LDLT recipients seem to have a more sustained decline in eGFR when compared with DDLT recipients.     

Influence of coronary artery disease assessment and treatment in the incidence of cardiac events in renal transplant recipients

De Lima JJG, Gowdak LHW, de Paula FJ, Arantes RL, Ianhez LE, Ramires JAF, Krieger EM. Influence of coronary artery disease assessment and treatment in the incidence of cardiac events in renal transplant recipients.
Clin Transplant 2010: 24: 474–480.
© 2009 John Wiley & Sons A/S. Abstract: Background: The best strategy for pre‐transplant investigation and treatment of coronary artery disease (CAD) is controversial. Methods: We evaluated 167 renal transplant recipients before transplantation to determine the incidence of cardiac events and death. We performed clinical evaluations and myocardial scans in all patients and coronary angiography in select patients. Results: Asymptomatic patients with normal myocardial scans (n = 57) had significantly fewer cardiac events (log‐rank = 0.0002) and deaths (log‐rank = 0.0005) than did patients with abnormal scans but no angiographic evidence of CAD (n = 76) and individuals with CAD (n = 34) documented angiographically. CAD increased the probability of events (HR = 2.27, % CI 1.007–5.11; p = 0.04). The incidence of cardiac events (log‐rank = 0.349) and deaths (log‐rank = 0.588) was similar among patients treated medically (n = 23) or by intervention (n = 11). Conclusion: Asymptomatic patients with normal myocardial scans had a better cardiac prognosis than did patients with or without CAD and positive for myocardial ischemia. Patients with altered scan and CAD had the poorer outcome. Guideline‐oriented medical treatment is safe and yields results comparable to coronary intervention in renal transplant patients with CAD. The data do not support pre‐emptive myocardial revascularization for renal transplant candidates.     

Clinical Burden of Screening Asymptomatic Patients for Coronary Artery Disease Prior to Liver Transplantation

The aim of this study is to assess the clinical burden of silent coronary artery disease (CAD) in cirrhotic candidates for liver transplantation (LT), and to evaluate the usefulness of a CAD screening approach. Between July 1999 and January 2006, we evaluated 627 LT candidates. All of them underwent a detailed clinical history. Sixteen had a previous diagnosis of CAD or symptoms suggestive (2.5%). The remaining 611 underwent further tests according to a predefined protocol, including EKG, echocardiogram and, on the basis of CAD risk factors, heart stress tests. Selective coronary angiography (SCA) was performed in the 30 patients with positive heart stress test: in only 2 did SCA show any CAD, and in both it was subcritical disease requiring neither intervention nor contraindicating LT. The 611 screened patients continued their follow-up until study closure or death. No coronary events occurred in the study population in a mean follow-up of 32.50 months (+/− 23.67 DS). No perioperative mortality related to CAD occurred in the 233 transplanted patients. In conclusion, no prognostic advantage was achieved by following a strict CAD screening protocol, leading us to believe that the cost-effectiveness of a similar screening can be unacceptably high in our setting.     

Outcomes of Endovascular Aortic Aneurysm Repair in Kidney Transplant Recipients: Results From a National Quality Initiative

Contrast‐induced nephropathy after endovascular aortic aneurysm repair (EVAR) in kidney transplant recipients (KTRs) can have devastating consequences. The Vascular Quality Initiative (VQI) database was queried to select all KTRs who underwent EVAR between January 2003 and December 2014. Our primary outcome was renal dysfunction, defined as acute kidney injury (AKI; elevation of serum creatinine >0.5 mg/dL from baseline) or new postoperative hemodialysis requirement. Within the EVAR VQI dataset, 40 patients were KTRs (40 of 17 213, or 0.2%). Renal dysfunction occurred in five of 40 patients in the KTR group in comparison to 779 of 17 173 patients in the nontransplanted group (12.5% versus 4.5%, p < 0.01). Emergent EVAR was required in 2 (5%) patients, one of whom required dialysis after surgery and subsequently died. One‐year survival after EVAR was similar in the two groups (92.9% versus 93.1%, p = 0.73). KTRs who developed renal dysfunction had significantly lower preoperative estimated glomerular filtration rates (eGFRs) (29.5 versus 54.7, p = 0.007) and a significantly higher iodine:eGFR ratio (0.78 versus 0.39, p = 0.02) despite receiving a similar volume of contrast (70.0 versus 68.8, p = 0.97). Renal dysfunction is 3 times more frequent in KTRs treated with EVAR, though overall survival did not differ between the groups. Decreased preoperative eGFR and a higher iodine:eGFR ratio are associated with postoperative renal dysfunction.     

Cardiogenic shock and coronary endothelial dysfunction predict cardiac allograft vasculopathy after heart transplantation

Cardiac allograft vasculopathy remains one of the major causes of death post‐heart transplantation. Its etiology is multifactorial and prevention is challenging. The aim of this study was to prospectively determine factors related to cardiac allograft vasculopathy after heart transplantation. This research was planned on 179 patients submitted to heart transplant. Performance of an early coronary angiography with endothelial function evaluation was scheduled at three‐month post‐transplant. Patients underwent a second coronary angiography after five‐yr follow‐up. At the 5‐ ± 2‐yr follow‐up, 43% of the patients had developed cardiac allograft vasculopathy (severe in 26% of them). Three independent predictors of cardiac allograft vasculopathy were identified: cardiogenic shock at the time of the transplant operation (OR: 6.49; 95% CI: 1.86–22.7, p = 0.003); early coronary endothelial dysfunction (OR: 3.9; 95% CI: 1.49–10.2, p = 0.006), and older donor age (OR: 1.05; 95% CI: 1.00–1.10, p = 0.044). Besides early endothelial coronary dysfunction and older donor age, a new predictor for development of cardiac allograft vasculopathy was identified: cardiogenic shock at the time of transplantation. In these high‐risk patient subgroups, preventive measures (treatment of cardiovascular risk factors, use of novel immunosuppressive agents such as mTOR inhibitors) should be earlier and much more aggressive.     

Pre‐existing diabetes significantly increases the risk of graft failure and mortality following renal transplantation

The aim of this study was to examine the impact of pre‐existing diabetes mellitus (DM) on acute rejection, graft loss, and mortality following kidney transplant and whether glycemic control or cardiovascular disease (CVD) risk control with medications influenced outcomes. This was a cohort study of 1002 renal transplants conducted between 2000 and 2008. Patients were included if they received a kidney transplant within the allotted time and were at least 18 yr of age. Cox regression was used to assess acute rejection, graft failure, or death controlling for relevant sociodemographic, clinical, and post‐transplant variables. Five‐yr patient survival (83% vs. 93%, p < 0.001) and graft survival (74% vs. 79%, p = 0.005) were significantly lower in patients with pre‐existing DM. Sequential Cox regression models demonstrated that pre‐existing DM was consistently associated with a higher risk of death (HR 2.3–3.0, p < 0.01) and graft failure (HR 1.5–1.8, p < 0.04) in all models except after adjusting for CVD medication use (HR 1.9, p = 0.174 and HR 1.5, p = 0.210, respectively). These data suggest pre‐existing DM is a significant risk factor for graft failure and death following renal transplantation and aggressive CVD risk reduction with medications may be an important strategy to reduce mortality and graft failure.     

Hepatocellular carcinoma in Child's A cirrhosis: a retrospective analysis of matched pairs following liver transplantation vs. liver resection according to the intention‐to‐treat principle

This is the first matched pair analysis on the puzzling clinical problem of whether to perform liver transplantation (LT) or liver resection (LR) for Child's A hepatocellular carcinoma (HCC) patients. A total of 201 patients diagnosed with HCC and Child's A liver cirrhosis were treated with LT transarterial chemoembolization (TACE) or LR between 1998 and 2012. To achieve the most accurate study design, two groups of 57 patients were matched retrospectively according to their tumor characteristics detected by the initial computerized tomography (CT) scan. Sixteen of 57 LT candidates were not transplanted due to tumor progress during pre‐treatment (TACE). Nevertheless, the retrospective analysis of the matched pairs according to the intention‐to‐treat principle resulted in a better five‐yr overall survival (OS) rate of 54.3% for the group of LT candidates compared with 35.7% for those receiving LR (p = 0.19). In patients meeting the University of California, San Francisco (UCSF) criteria, five‐yr OS reached 58.4% after LT and 45.1% after LR (p = 0.56). For Milan criteria (MC) patients, LT resulted in 57.9% and LR in 42% five‐yr OS rate (p = 0.29). In conclusion, the finding of a better OS rate in LT was not statistically significant. There was also a selection bias in favor of LT, which may have influenced the OS. Therefore, particularly in regard to organ scarcity, LR remains a viable treatment option for respectable HCC in Child's A cirrhosis.     

The clinical significance of intrapulmonary vascular dilations in liver transplant candidates

Intrapulmonary vascular dilations (IPVD) are common in patients with cirrhosis, but the majority do not have hepatopulmonary syndrome (HPS). The clinical significance of IPVD is unknown. Our aim was to determine the clinical impact due to the entire spectrum of IPVD in liver transplant (LT) candidates. A total of 122 evaluees for LT underwent contrast transthoracic echocardiography (cTTE). The degree of shunting was graded 1–3 (severe). HPS was defined as PaO₂ < 70 mmHg in the presence of IPVD and exclusion of other causes of hypoxemia. IPVD were detected in 57/122 (47%), and of these HPS was found in 5. IPVD were associated with higher Alveolar‐arterial (A‐a) gradients, with the highest occurring in patients with HPS (IPVD vs. no IPVD: p = 0.003; HPS vs. no IPVD: p = 0.004). All patients with HPS had grade 3 shunting, and had significantly widened A‐a gradient and lower PaO₂ compared with grade 1 or 2 IPVDs. Presence of IPVD did not affect survival measured from evaluation or after LT. Other clinical outcomes were also similar among patients with and without IPVD. IPVD are common among LT candidates. HPS is unlikely in presence of only mild to moderate shunting. Clinical outcomes are similar among patients with and without IPVD.     

Ultrasonography in the evaluation of renal scarring using DMSA scan as the gold standard

Dimercaptosuccinic acid (DMSA) renal scan is presently the technique of choice for assessing renal scars. Recent advances suggest that ultrasonography could replace DMSA scan for this purpose. This paper describes the experience of a tertiary pediatric referral hospital performing ultrasonography and DMSA scans in the assessment of renal scarring. Investigations were conducted 3–6 months after patients presented with urinary tract infection (UTI). Results were extracted from the radiology information system and recorded for analysis. All children with a UTI who had undergone DMSA and ultrasound examination on the same day between January 1995 and December 1999 were included; 930 kidneys were compared. DMSA scan was utilized as the reference method. When used to detect focal renal scarring, ultrasonography had a sensitivity of 5.2%, specificity of 98.3%, a positive predictive value (PPV) of 50% and a negative predictive value (NPV) of 75.8%. When used to detect diffuse renal scarring, ultrasonography had a sensitivity of 47.2%, specificity of 91.8%, PPV of 60.8% and NPV of 86.6%. Our results demonstrate that although ultrasonography has a good specificity for the detection of renal scarring compared with DMSA, it has low sensitivity, PPV and NPV. Ultrasonography cannot be substituted for DMSA scan in the evaluation of focal renal scarring.