Disparities over Time in Volume, Day of the Week, and Patient Complexity between Paracentesis and Thoracentesis Procedures Performed by Radiologists versus Those Performed by Nonradiologists

Clinical question
Does complexity or day of the week affect whether a radiologist or non-radiologist performs a paracentesis or thoracentesis?

Take-away point
Radiologists are performing an increasingly larger portion of paracenteses and thoracenteses over time, however the proportion is higher on weekdays.

Reference
Gottumukkala, RV et al. Disparities over Time in Volume, Day of the Week, and Patient Complexity between Paracentesis and Thoracentesis Procedures Performed by Radiologists versus Those Performed by Nonradiologists. Journal of Vascular and Interventional Radiology. Nov, 2019: 30; 11, 1769-1778

Click here for abstract

Study design
Retrospective

Funding source
Self-funded or unfunded

Setting
Patient-level 5% Medicare Part B Research Identifiable Files





Figure 1. Proportion of total weekend and weekday volumes of paracenteses performed by radiologists compared with those performed by nonradiologists from 2004 to 2016. The vertical axis scale on the left reflects the percentages of the weekday volume performed by radiologists and nonradiologists (solid lines). The vertical axis scale on the right reflects the percentages of weekend volume performed by radiologists and nonradiologists (dashed lines).

Summary

Paracenteses and thoracenteses are common procedures that can be performed by radiologists and non-radiologists. Many radiologists have surmised that these procedures are being disproportionally referred to radiology after hours and on weekends. A 5% Medicare beneficiary cohort was evaluated over a 12 year period of time. The proportion of radiology performed paracenteses increased from 70% in 2004 to 80% in 2016. Likewise, the proportion of radiology performed thoracenteses increased from 45% to 65% over the same time period. Weekday paracenteses performed by radiologists increased from 71% to 80%, while weekend proportion increased from 57% to 68%. Weekday thoracentesis performed by radiologists increased from 47% to 66%, while weekend proportion increased from 29% to 54%. There was no difference in patient comorbidities over the final three years of the study for the patients who underwent a procedure by radiology versus other services.

The authors hypothesize that the increasing referral of these procedures to radiologists could be secondary to atrophy of procedural skill amongst Internal Medicine physicians, duty hour restrictions, competing clinical responsibilities, poor reimbursement of the procedures, and lack of available ultrasounds. The study also concluded that while radiologists and performing and increasing larger proportion of procedures over time, a greater share is still performed on weekdays than weekends. This finding differs compared to similar study of diagnostic procedures with similar inter-specialty dynamics. The results imply that selective referral of procedures to radiologists after and on more complex patients does not apply to paracenteses and thoracenteses.

Commentary

While the authors concluded that there is not a selective referral bias on paracenteses and thoracenteses, proportional rate of growth was greater on weekends than weekdays, suggesting that if this trend continues, a referral bias could be proven in the future. The overall percentages and volume speaks to the need of small procedure rooms within radiology to perform small procedures in a timely and cost effective manner. Dynamics are incredibly variable between institutions, and how nationwide trends applies to a singular institution is unclear.

Post Author
David M Mauro, MD
Assistant Professor
Department of Radiology, Vascular and Interventional Radiology
University of North Carolina

@DavidMauroMD

Sedation with Propofol During Catheter-Directed Thrombolysis for Acute Submassive Pulmonary Embolism Is Associated with Increased Mortality

Clinical Question
Does the type of sedation used during catheter directed thrombolysis for patients with acute submassive pulmonary embolism (PE) impact survival?

Reference
Manchec, B. et al. Sedation with Propofol During Catheter-Directed Thrombolysis for Acute Submassive Pulmonary Embolism Is Associated with Increased Mortality. J. Vasc. Interv. Radiol. 30, 1719–1724 (2019).

Study Design
Single-institution, retrospective study with 136 patients from 2011-2017 who underwent catheter directed thrombolysis for submassive PE. Primary endpoint was in-hospital mortality.

Funding Source
None

Setting
AdventHealth Medical Group, Orlando, Florida

Summary

Most catheter directed thrombolysis (CDT) is performed with the use of intravenous anesthetics such as propofol and benzodiazepines often combined with opioids such as fentanyl for analgesia. The authors describe that propofol has been shown to decrease blood pressure and dampen baroreceptor reflex among other cardiovascular/cardiopulmonary side effects. Coupled with altered hemodynamics in patients with submassive PE (right heart failure, which may progress to left heart failure and systemic hypotension) selection of sedation must be carefully considered.

This study explores whether the type of sedation (propofol versus midazolam/fentanyl) used during CDT for patients with submassive PE impacts in-hospital mortality.

Inclusion criteria were right to left ventricular (RV/LV) ratio > 0.9, symptom onset within 14 days, CDT during hospitalization, and sedation with propofol or midazolam and/or fentanyl during CDT. Exclusion criteria were acute massive PE, procedure performed without sedation or sedation was not clearly recorded. Of the 136 patients who met inclusion criteria, 25 received propofol and 111 received midazolam/fentanyl. In-hospital mortality was 28% in the propofol group compared to 3% in the midazolam/fentanyl group (P=0.0003). Patients sedated with propofol had 10.4 times the risk of cardiopulmonary arrest or dying during hospitalization compared with patients receiving fentanyl and/or midazolam (95% confidence interval, 2.9-37.3, P=0.0003).

There was no significant difference in comorbidities such as malignancy, heart failure and chronic obstructive pulmonary disease between groups. While patients in the propofol group were younger, with more ASA IV classification and were more likely to be intubated prior to the procedure, propensity-matched analysis showed a persistent statistically significant increase in mortality (P=0.01). Logistic regression showed that PESI score, RV/LV ratio and age were not predictive of mortality (P=0.19). The number needed to harm was 4 (95% confidence interval, 2.8-6.8).

Similar results have been described with other procedures outside IR (such as with bronchoscopy and endoscopy); however, the reason why patients sedated with propofol have worse outcomes is unknown. Nonetheless, these preliminary results prompted the authors to recommend against the use of propofol during CDT for submassive PE until further studies can establish clear guidelines.

Commentary 

Increased use of CDT for acute submassive pulmonary embolism has led to important questions regarding all aspects of treatment to optimize patient outcomes and to minimize risks. However, lack of standardization of CDT in practice (type of catheter used, tPA dose, duration of infusion) makes the establishment of guidelines difficult. Similarly, these variables in practice patterns were not elucidated in this retrospective review. Additionally, it would be interesting to identify what percentage of patients did not require sedation or anesthesia support and to document those outcomes. This preliminary data will undoubtedly prompt meaningful discussion prior to CDT when sedation is required.

Post AuthorTeodora Bochnakova MD
Assistant Professor
Department of Interventional Radiology
Oregon Health and Science University, Portland, OR
@T_bochnakova

Randomized clinical trial of Balloon Occlusion versus Conventional Microcatheter Prostatic Artery Embolization (PAE) for Benign Prostatic Hyperplasia (BPH)

Clinical question
What is the safety and efficacy of balloon occlusion PAE (bPAE) versus conventional microcatheter PAE (cPAE)?

Take-away point
bPAE is as effective as cPAE in treating BPH with the potential to reduce non target embolization. 

Reference
Bilhim, Tiago et al. Randomized Clinical Trial of Balloon Occlusion versus Conventional Microcatheter Prostatic Artery Embolization for Benign Prostatic Hyperplasia. Journal of Vascular and Interventional Radiology, Volume 30, Issue 11, 1798 - 1806.

Click here for abstract

Study design

Prospective randomized single-blind clinical trial

Funding source

Self-funded or unfunded 

Setting
Single-center






Figure 5. DSA images with balloon catheter not inflated (a) and then with balloon catheter inflated (b).


Summary

Prostatic artery embolization is gaining increasing acceptance as a minimally invasive treatment for men with benign prostatic hypertrophy. Despite, its increased utilization, clinical failure rates approach 25%. Additionally, complex arterial anatomy and the presence of arterial anastomoses which may lead to non target embolization remains a concern and makes this one of the more challenging procedures we offer our patients. Balloon occlusion PAE (bPAE) may reduce this risk of non target embolization and also increase the efficacy of PAE by improving embolic penetration.

In this prospective randomized single-blind clinical trial, 89 patients were randomly assigned to cPAE (Maestro; n=43) or bPAE (Sniper; n=46), with no difference in efficacy variables between the two groups. In the cPAE group, embolization was performed after advancing the microcatheter as distal as possible into the intraprostatic branches. In the bPAE group, embolization was performed via the balloon occlusion catheter positioned within the middle third of the prostatic artery. Coil embolization was performed when necessary. No patients crossed over from bPAE to cPAE or vice versa. Patients were reevaluated at 1 month and 6 months post PAE. The parameters assessed were IPSS (primary outcome)/quality of life and International Index of Erectile Function scores, prostate volume measured with transrectal ultrasound, prostate-specific antigen (PSA), uroflowmetry measuring peak flow rate, and post-void residual.

Procedural time and radiation dose did not differ between the cPAE and bPAE groups. Perhaps somewhat unexpectedly, there was no difference in coil usage or in embolic volume between cPAE and bPAE. Relating to outcomes, the change in baseline of IPSS was not statistically significant between the cPAE and bPAE groups (mean change from baseline was 7.58 points ± 6.88 and 8.30 points ± 8.12 in the cPAE and bPAE groups, respectively). The reduction in prostate volume was 21.9 cm3 ± 51.6 and 6.15 cm3 ± 14.6 in the cPAE and bPAE groups, respectively (P =.05). None of the other outcome variables showed statistical significance between the two groups.

There were no major adverse events in either group. Minor adverse events were seen in both groups. Of note, penile skin lesions (n=3; 7.0%) and rectal bleeding (n=2; 4.7%) were only seen in patients in the cPAE group (11.7%, P=.01).

Commentary

While bPAE did not demonstrate a significant improvement from baseline IPSS compared to cPAE in this trial, it appears to be just as efficacious as cPAE with a decreased potential for non-target embolization (bPAE showed significantly less penile lesions and rectal bleeding compared to cPAE; other minor adverse events were similar). Further investigations into catheter size and type, embolic type, size and volume, and the use of adjunct pharmacotherapy in PAE are necessary but this trial is important because it gives us the ability to further refine our techniques for this emerging treatment and achieve less morbidity for our patients.

Post Author
Zagum Bhatti, MD
Assistant Professor
Department of Vascular & Interventional Radiology
University of Texas Health Science Center at Houston-McGovern Medical School, Houston, TX
@ZagumBhatti

Chemoembolization Combined with Radiofrequency Ablation for Medium-Sized Hepatocellular Carcinoma: A Propensity-Score Analysis

 
Clinical question
Compare the effectiveness of combined chemoembolization and RF ablation, chemoembolization alone, and RF ablation alone in the treatment of patients with medium-sized HCC’s (3-5cm in size).

Take away point
Large-bore aspiration mechanical thrombectomy is safe with a high technical (100%) and clinical success (88%) rates.

Reference
Chu, Hee Ho et al. Chemoembolization Combined with Radiofrequency ablation for Medium-Sized Hepatocellular Carcinoma: A Propensity-Score Analysis. Journal of Vascular and Interventional Radiology, Volume 30, Issue 10, 1533-43

Click here for abstract

Study design
Single center, retrospective, cohort study of 538 patients treated between March 2000 – December 2016, with follow up until March 2018

Funding Source
None

Setting
Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.





Figure 2
Flow chart to determine treatment of a single medium-sized (3.1-5.0 cm) HCC. Patients included in this study were unsuitable for surgery or liver transplantation and had one the three treatments.

Summary

Definitive treatment of single medium-sized HCC, according to Barcelona Clinic Liver Cancer (BCLC), is surgical resection. However, this is not always feasible secondary to patient comorbidities and/or tumor location. Radiofrequency (RF) ablation is considered as curative in patients with small (<3cm) HCC’s. However, no such definitive literature exits for single lesions that fall in the medium-size range, between 3-5 cm. Multiple treatment modalities have been used to treat these medium sized lesions including a combination of TACE and RF ablation, TACE alone, and RF alone. The authors performed a retrospective analysis of these treatment types in patients with single medium sized HCC. Additionally they took their data and performed a propensity-score analysis with inverse probability weighting to reduce bias in treatment selection and other confounding variables.

All patients in this study has single medium sized HCC’s and were treated with one of the three therapies. The treatment pathways were chosen as the digression of the interventionist. TACE was performed with a combination of Lipiodol and Cisplatin (1:1 ratio) with a cisplatin dose of 2mg/kg body weight. Gel-foam slurry was infused after administration until arterial stasis was achieved. RF ablation was performed under ultrasound guidance within 2 weeks of chemoembolization (if performed). Of note there were statistically significant differences in the patient population with regards to Child-Pugh class, serum albumin level and tumor size. No major complications were reported as defined by SIR criteria.

The primary endpoint was overall survival (OS) from initial procedure to death. The secondary endpoint was recurrence free survival (RFS), which was determined from initial treatment to recurrence or death. Recurrence included local or distant recurrence and local was defined by a margin of 1 cm.

The mean follow up time for all patients was 59.6 months (SD – 46.9 mo; range: 2-208). Overall survival in combined, chemoembolization-only, and RF-only were 85 mo (95% CI: 51.2-118.8 mo), 56.5 mo (95% CI: 51.7-61.3 mo), and 52.1 mo (95% CI: 40.7-63.5 mo), respectively. Treatment was found to be a significant independent factor associated with OS (P=0.023). During follow up recurrent disease was found in 68.8% of combined group, 78% of the chemoembolization-only group, and 74.8% of the RF-only group. RFS in the combined, chemoembolization-only, and RF-only were 26.5 mo (95% CI: 22-31 mo), 14.1 mo (95% CI: 10.9-17.3 mo), and 14.1 mo (95% CI 9.7-18.5 mo), respectively.

Inverse probability weighting was performed to balance baseline characteristics. The differences in OS remained statistically significant with a P value of 0.022 (Fig 4a). Additionally the differences in RFS values were statistically significant with a P value of 0.002 (Fig 4b).

Commentary

The authors performed a similar study to multiple previous authors, with a much larger patient sample. The findings of this study fit and reinforce all of the current data in treating “unresectable” medium-sized HCC’s. However, the retrospective nature of the study and single center analysis limits its broad applications. Taking this into consideration we now have a larger pool of retrospective data to help reinforce the current trend in treating medium-sized HCC’s. This study provides evidence for future prospective studies to look at this question and help solidify an evolving treatment paradigm.

Post Author
Hasnain Hasham, MD
Interventional Radiology Fellow
Dotter Interventional Institute
Oregon Health and Science University, Portland, OR
@irhasham