The current role of precision surgery in oligometastatic prostate cancer

Oligometastatic prostate cancer (omPCa) is a novel intermediate disease state characterized by a limited volume of metastatic cells and specific locations. Accurate staging is paramount to unmask oligometastatic disease, as provided by prostate-specific membrane antigen-positron emission tomography. Driven by the results of prospective trials employing conventional and/or modern staging modalities, the treatment landscape of omPCa has rapidly evolved over the last years. Several treatment-related questions comprising the concept of precision strikes are under development. For example, beyond systemic therapy, cohort studies have found that cytoreductive radical prostatectomy (CRP) can confer a survival benefit in select patients with omPCa. More importantly, CRP has been consistently shown to improve long-term local symptoms when the tumor progresses across disease states due to resistance to systemic therapies. Metastasis-directed treatments have also emerged as a promising treatment option due to the visibility of oligometastatic disease and new technologies as well as treatment strategies to target the novel PCa colonies. Whether metastases are present at primary cancer diagnosis or detected upon biochemical recurrence after treatment with curative intent, targeted yet decisive elimination of disseminated tumor cell hotspots is thought to improve survival outcomes. One such strategy is salvage lymph node dissection in oligorecurrent PCa which can alter the natural history of progressive PCa. In this review, we will highlight how refinements in modern staging modalities change the classification and treatment of (oligo-)metastatic PCa. Further, we will also discuss the current role and future directions of precision surgery in omPCa.

Intravenous vagal stimulation catheter, JOHAKU, rapidly decreases heart rate and myocardial oxygen consumption without worsening hemodynamics

Background

Rapid reduction of heart rate (HR) is the most evident physiological response of vagal nerve stimulation (VNS). Since HR reduction is the most potent factor to decrease myocardial oxygen consumption rate (MVO2), the appropriate VNS can exert cardio-protective effects. It is also known that VNS reduces inflammation, oxidative stress, and sympathetic overload. In addition, the VNS during ischemia-reperfusion is known to attenuate myocardial damage by studies in various animal species. Despite the presence of preclinical evidence of VNS benefits, the lack of the device has limited the translation of this technology to clinical practice. We have recently developed an intravenous VNS catheter (JOHAKU, Neuroceuticals Inc.) that can stimulate the right vagal nerve via superior vena cava (SVC) (Figure 1) on temporary basis.

Purpose

We aimed to confirm the feasibility of JOHAKU as a device to modulate heart rate and MVO2 rapidly by a canine experiment.

Methods

In eight beagle dogs, JOHAKU was inserted from the right femoral vein and placed at the SVC level. The stimulation intensity was adjusted to 10–20 V (20 Hz). We simultaneously recorded electrocardiogram and intraarterial blood pressure (BP). In three of eight dogs, we measured the left anterior descending coronary artery flow and oxygen saturations of arterial and coronary sinus blood to calculate MVO2. We compared HR, BP, and MVO2 during JOHAKU stimulation to ones at baseline.

Results

As shown in Figure 2, JOHAKU attenuated HR immediately after stimulation. Compared with baseline, JOHAKU significantly reduced HR (baseline: 135±13 vs. 5 min on stimulation: 107±13 bpm, p<0.05), and did not affect mean BP significantly (96.2±22.8 vs. 89.4±26.6 mmHg, P=0.59). HR promptly recovered to baseline level after JOHAKU stopped. JOHAKU also reduced MVO2 (0.57±0.43 vs. 0.48±0.38 ml/min, p<0.05).

Conclusion

JOHAKU rapidly attenuated cardiac metabolism burden via the rapid HR reduction. The controllability of HR by JOHAKU without affecting BP enables us to apply the VNS even for patients with hemodynamic instability, such as heart failure and acute myocardial infarction.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Japan Agency for Medical and Research Development

Letter to the Editor: Childhood Secondhand Smoke Exposure and Risk of Dementia in Adulthood

I read the paper by Zhou et al. with great interest (1). The authors conducted a long-term follow-up study to investigate the associations between exposure to secondhand smoke and the subsequent risk of dementia, Alzheimer's disease (AD), and stroke (1). The adjusted hazard ratios (HRs; 95% confidence intervals [CIs]) of the highest exposure to secondhand smoke compared to individuals with no exposure for dementia, AD, and stroke were 2.86 (2.00–4.09), 3.13 (1.80–5.42), and 1.89 (1.37–2.61), respectively. In addition, a dose–response relationship was also observed in this study. I would like to present some information relevant to their study.

Effective reflection distance and its association with pressure augmentation index under a variety of acute hemodynamic perturbation

 

Effective reflection distance (ERD), a conceptual distance to a major reflection site from the aortic root, is associated with aging and pressure augmentation index (AIx) in clinical population. However, it is poorly understood how ERD varies and associates with AIx within a subject when the hemodynamic condition is changed extensively by acute pharmacological interventions.

Methods

In 13 anesthetized dogs, we measured aortic pressure (AP) and flow (AF) and femoral arterial flow (FF). Using AP, AF and FF, ERD based on an arterial model comprising a tube with frequency-dependent load (ERD_TL) was determined as a physiologically valid reference. ERD was also determined by wave separation (ERD_WSA) and pressure-only analyses (ERD_AW). Hemodynamic condition was changed by administrating zatebradine (bradycardic agent), nitroprusside, noradrenaline, dobutamine, and dextran.

Results

ERD_TL shortened significantly in response to infusion of nitroprusside or dobutamine. ERD_TL was significantly and negatively associated with AIx in multivariate analysis (Figure/Table). Changes in ERD_WSA or ERD_AW, and their association with AIx were not necessarily concordant with those observed in ERD_TL.

Conclusion

For the first time, we demonstrated that under diverse hemodynamic conditions, ERD_TL can change sensitively, and associates with AIx physiologically. This substantiates importance of tight attention to medication at clinical analysis of wave reflection phenomena. ERD_WSA or ERD_AW may not be a surrogate of ERD_TL.

Responses of ERD to drugs

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Japan Society for the Promotion of Science (JSPS)

Donepezil markedly prevents the progression of chronic heart failure and renal dysfunction in renal artery stenosis-induced hypertensive rats

Introduction

Parasympathetic activation by donepezil has been shown to improve prognosis in chronic heart failure (CHF) rats following myocardial infarction. We examined whether donepezil is effective in the treatment of another CHF model complicated with renal artery stenosis (RAS)-induced hypertension.

Methods

RAS was created by ligating the left renal artery up to 50% in SD rats, at the same time, we implanted a blood pressure (BP) transmitter for confirming RAS-induced hypertension (7-week post-RAS: systolic BP = 154±7 mmHg; diastolic BP = 115±8 mmHg). In the 11th week after induction of RAS, surviving animals were randomly assigned to untreated (UT, n=10) or donepezil treated [DT, n=10, dissolved in drinking water (3mg/kg/day)] group. After a 6-week treatment, the effects of donepezil were evaluated by hemodynamics, blood levels of neurohumoral markers, and morphology.

Results

Compared with UT, DT significantly prevented the progression of the left kidney atrophy (2.38±0.13 vs. 1.51±0.34 g/kg, P<0.05) and kidney fibrosis (left: −64%, P<0.001; right: −55%, P<0.01). DT also significantly prevented the progression of CHF, through suppressing cardiac hypertrophy (2.30±0.06 vs. 2.57±0.08 g/kg, P<0.01), cardiac fibrosis (−70%, P<0.01), and cardiac dysfunction [cardiac index: 102±3 vs. 86±3 ml/min/kg, P<0.05; left ventricular (LV) end-diastolic pressure: 12±2 vs. 20±2 mmHg, P<0.05; LV dp/dtmin: 5856±259 vs. 4924±227 mmHg/sec, P<0.05]. DT not only decreased serum levels of creatinine (0.54±0.02 vs. 0.63±0.03 mg/dl, P<0.05) and uric acid (1.4±0.2 vs. 1.9±0.2 mg/dl, P<0.05); but also decreased plasma levels of norepinephrine (273±38 vs. 846±242, P<0.01), AVP (2729±347 vs. 4783±695 pg/ml, P<0.05), BNP (360±13 vs. 460±39 pg/ml, P<0.05), angiotensin II and aldosteron, and suppressed the systemic inflammation.

Conclusions

Donepezil treatment markedly prevented the progression of CHF and renal dysfunction, and improved the neurohumoral markers in the CHF rat model complicated with RAS-induced hypertension, suggesting that donepezil may be used as a new pharmacotherapy for CHF patients complicated with RAS-induced hypertension.

Funding Acknowledgement

Type of funding source: None

A minimally-occlusive cuff method utilizing ultrasound vascular imaging for stress-free blood pressure measurement

Objective

Occlusive cuff inflation in ambulatory blood pressure (BP) monitoring disturbs the daily life of the user, and affects efficacy of monitoring. To overcome this limitation, we have developed a novel minimally-occlusive cuff method for stress-free measurement of BP. This study aimed to experimentally evaluate the reliability of this method, and improve the precision of this method by implementing a machine learning algorithm.

Methods

In this method, a thin-plate-type ultrasound probe (Size: 5.6mm-thickness × 28mm × 26mm; weight: 10g) is placed between the cuff and the skin, and used to measure the ultrasonic dimension of the artery (Figure 1). The cuff pressure (Pc), arterial dimension at systole (Ds) and diastole (Dd), systolic BP (SBP) and diastolic BP (DBP) during cuff inflation are theoretically related by the following equations,

SBP-Pc = P0·Exp[α·Ds]

DBP-Pc = P0·Exp[α·Dd]

Where P0 and α are constants, and α indicates arterial stiffness. Since multiple sets of the two equations can be defined over multiple cardiac beats while measuring Pc, Ds and Dd during mild cuff inflation (Pc is controlled less than 50 mmHg, Figure 1), it is possible to estimate SBP (SBPe) and DBP (DBPe) as solutions of the equations. In 6 anesthetized dogs, we attached the cuff and the probe to the right thigh to get SBPe and DBPe, which were one-time calibrated in each animal against reference SBP and DBP measured by using an intra-arterial catheter. We also determined the pulse arrival time (PAT), which is a commonly employed parameter in cuff-less BP monitoring. In all the dogs, BP was changed extensively by infusing noradrenaline or sodium nitroprusside.

Results

DBPe correlated tightly with DBP with a coefficient of determination (R2) of 0.85±0.08, and predicted DBP with error of 3.9±7.9 mmHg after one-time calibration (Figure 2). PAT correlated poorly with DBP (R2=0.49±0.17), and predicted DBP less accurately than this method. SBPe correlated well with SBP (R2=0.78±0.08) (Figure 3). However, even after one-time calibration, difference between SBPe and SBP was 2.6±18.9 mmHg, which was not acceptable. To improve the precision in SBP prediction, we used supervised machine learning approach with use of a support vector algorithm (Python, Scikit-learn), which regressed feature variables (SBPe, DBPe, Ds, Dd heart rate, and PAT) against teacher signal (reference SBP). The support vector algorithm, once trained, predicted SBP with acceptable accuracy with error of 0.7±6.9 mmHg (Figure 3).

Conclusions

This method reliably tracks BP changes without occlusive cuff inflation. Once calibrated, this method measures DBP accurately. With the aid of machine learning, precision in SBP prediction was greatly improved to an acceptable level. This method with machine learning approach has potential for stress-free BP measurement in ambulatory BP monitoring.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Japan Society for the Promotion of Science

Donepezil as a novel therapy for suppressing the progression of cardiovascular remodeling in obesity-induced hypertensive rats with reperfused myocardial infarction

Introduction

Acetylcholinesterase inhibition by donepezil has been shown to improve long-term survival in permanent myocardial infarction (MI)-induced chronic heart failure rats. This study examined whether donepezil is applicable to the treatment of obesity-induced hypertension with reperfused MI (RMI).

Methods

Four-week-old SD rats were fed a high-fat diet (57% kcal as fat) for 15 weeks. We implanted a blood pressure (BP) telemetry into the animals (8-week-old) for monitoring artery pressure. After a 1-week recovery, RMI was created by occluding the left coronary artery (30min) followed by reperfusion. Surviving animals were randomly assigned to untreated (UT, n=16) or donepezil treated (DT, n=16, 3 mg/kg/day) group. After a 10-week treatment, the effects of donepezil were evaluated by hemodynamics, blood biomarkers, immunohistochemistry, and morphology.

Results

The high-fat diet caused obesity and hypertension (9-week-old: systolic BP = 134±4 mmHg; diastolic BP = 92±2 mmHg) in the normal rats. Compared with UT, DT significantly decreased the heart rate (296±5 vs. 318±8 bpm, P<0.05). DT significantly prevented the progression of cardiac remodeling and dysfunction [cardiac index: 91±4 vs. 73±9 ml/min/kg, P<0.01; left ventricular (LV) end-diastolic pressure: 11±1 vs. 20±2 mmHg, P<0.01; LV dp/dt max: 5347±206 vs. 3637±433 mmHg/sec, P<0.01], through increasing capillary density (+120%/field, P<0.001), reducing cardiac fibrosis (−50%, P<0.01) and myocardial infarcted area (17±2 vs. 24±2%, P<0.05), suppressing cardiac hypertrophy (2.35±0.04 vs. 2.70±0.14 g/kg, P<0.01) and coronary artery remodeling (wall thickness: 30±1 vs. 37±2 mm, P<0.01; media-to-lumen ratio: 2.3±0.2 vs. 6.2±1.6, P<0.001). Additionally, DT not only decreased plasma levels of insulin, norepinephrine, BNP, angiotensin II, but also improved the systemic inflammation.

Conclusions

Donepezil treatment significantly suppressed the progression of cardiovascular remodeling and dysfunction following RMI in obesity-induced hypertensive rats, suggesting that donepezil may be used as a potential candidate for post-RMI therapy in obesity-induced hypertensive patients.

Funding Acknowledgement

Type of funding source: None

P105 Chronic vagal nerve stimulation suppress thirst through decreasing vasopressin secretion in the rats with chronic heart failure

Introduction

Chronic right cervical vagal nerve electric stimulation (VS) exerted prognostic benefits in heart failure rats. Exploring the mechanism is significant for clinical application. This study examined the effect of VS on arginine vasopressin (AVP) secretion and drinking behavior in the rats with chronic heart failure.

Methods

After a week recovery of myocardial infarction (MI), surviving rats after were randomly instrumented to VS group and sham stimulation (SS) group. A drop sensor was used to record real-time fluid consumption. Blood samples were collected weekly from the 3rd week during the 6 weeks treatment.

Results

Vagal stimulation did not change the daily fluid consumption (Mean ± SE, 76.2 ± 1.1 vs. 77.8 ± 2.1 ml/kg/day, n = 6, P < 0.05). Thirst, which is defined as per drinking volume (PDV), significantly increased during the early weeks after MI (Fig A), while VS significantly suppressed PDV (Fig B is the data of 6th week) by increasing the drinking intervals. The level of plasma AVP was increased to about 2 fold during 6 weeks observation in the SS group, however, VS suppressed this upregulation (Fig C).

Conclusion

These results suggest that VS may activate vagal afferent components which related to inhibition of AVP secretion and then suppressed the augmentation of thirst. Frequent drinking small volume may benefit for homeostasis in CHF.

Abstract P105 Figure. Drinking behavior and AVP

P3501Oral administration of donepezil markedly prevents the progression of chronic heart failure in renal artery stenosis-induced hypertensive rats

Introduction

Parasympathetic activation by donepezil has been shown to improve prognosis in chronic heart failure (CHF) rats following myocardial infarction. We examined whether donepezil is effective in the treatment of another CHF model complicated with renal artery stenosis (RAS)-induced hypertension.

Methods

RAS was created by ligating the left renal artery up to 50% in SD rats, at the same time, we implanted a blood pressure (BP) transmitter for confirming RAS-induced hypertension (7-week post-RAS: systolic BP = 154±7 mmHg; diastolic BP = 115±8 mmHg). At the 11th week after induction of RAS, surviving animals were randomly assigned to untreated (UT, n=10) or donepezil treated [DT, n=10, dissolved in drinking water (3mg/kg/day)] group. After a 6-week treatment, the effects of donepezil were evaluated by hemodynamics, blood levels of neurohumoral markers, and morphology.

Results

Compared with UT, DT significantly prevented the progression of the left kidney atrophy (2.38±0.13 vs. 1.51±0.34 g/kg, P<0.05). DT also significantly improved cardiac remodeling, through suppressing the progression of cardiac hypertrophy (2.30±0.06 vs. 2.57±0.08 g/kg, P<0.01), cardiac dysfunction [cardiac index: 102±3 vs. 86±3ml/min/kg, P<0.05; left ventricular (LV) end-diastolic pressure: 12±2 vs. 20±2 mmHg, P<0.05; LV dp/dtmin: 5856±259 vs. 4924±227 mmHg/sec, P<0.05]. DT not only decreased serum levels of creatinine (0.54±0.02 vs. 0.63±0.03 mg/dl, P<0.05) and uric acid (1.4±0.2 vs. 1.9±0.2 mg/dl, P<0.05); but also decreased plasma levels of norepinephrine (273±38 vs. 846±242, P<0.01), angiotensin II (17±2 vs. 23±2 pg/ml, P<0.05), AVP (2729±347 vs. 4783±695 pg/ml, P<0.05) and BNP (360±13 vs. 460±39 pg/ml, P<0.05), and suppressed the systemic inflammation (CRP: 190±12 vs. 382±58 mg/ml, P<0.01).

Conclusions

Donepezil treatment markedly prevented the progression of cardiac remodeling and renal dysfunction, and improved the neurohumoral markers in the CHF rat model complicated with RAS-induced hypertension, suggesting that donepezil may be used as a new pharmacotherapy for CHF patients complicated with RAS-induced hypertension.

P4605Landiolol, a beta-blocker, optimizes cardiac energetics and peripheral microhemodynamics better than ivabradine while reducing heart rate at hemodynamic resuscitation of experimental septic shock

Background

Septic shock is associated with sympathetic over-activation characterized by tachycardia, which is associated with poor survival. Though several kinds of drugs are available to reduce heart rate (HR), it is not clear which drug should be used to reduce HR effectively in initial hemodynamic resuscitation in septic shock.

Purpose

The aim of this study was to experimentally investigate comparative effects of landiolol (a β-blocker) and ivabradine (an If-channel inhibitor) on initial hemodynamic resuscitation in a canine model of endotoxin shock.

Methods

We used 19 anesthetized dogs. Seven dogs were allocated to control (CT) group, six dogs to landiolol (BB) group, and six dogs to ivabradine (IVA) group. In all the groups, endotoxin shock was induced by intravenous infusion of Escherichia coli lipopolysaccharide (4 mg/kg) over 1 h. After induction of endotoxin shock, we started hemodynamic resuscitation to restore mean arterial pressure (AP) and cardiac output (CO) by infusing noradrenaline (NA) and Ringer acetate solution (RiA). Dose of NA and RiA were automatically titrated with use of a computer-controlled drug infusion system that we developed previously. Hemodynamic resuscitation was continued for 4 h. During resuscitation, the BB group was given landiolol infusion at a low-dose range (1–10 μg/kg/min, manually titrated), while the IVA group was given ivabradine at 0.25 mg/kg bolus-injected every 2 h.

Results

The drug infusion system automatically restored AP to 70 mmHg and CO to greater than 90% of baseline level in all the groups. The restored AP and CO were not significantly different among the three groups (Figure A, B). There were no significant differences in the computer-controlled infusion rate of NA and cumulated volume of RiA infused among the three groups (Figure C). During the first 2 h of resuscitation, HR was significantly reduced in the BB and IVA groups in comparison to the CT group (Figure D). However, only in the BB group, cardiac oxygen consumption was significantly lower than that in the CT group (Figure E). Blood lactate level decreased significantly after hemodynamic resuscitation only within the BB group (Figure F).

Figure 1

Conclusions

In the initial hemodynamic resuscitation of septic shock, both low-dose landiolol infusion and ivabradine injection may be used to reduce HR. However, to optimize cardiac energetics and peripheral microhemodynamics, low-dose landiolol infusion may be preferable to ivabradine injection.

Acknowledgement/Funding

This work was supported by JSPS KAKENHI Grant Number 15K01307, 18K12126.

Estimation of Arterial Mechanical Properties from Aortic and Tonometric Arterial Pressure Waveforms

Although arterial mechanical properties have been evaluated using arterial input impedance, the relative difficulty in accurate flow measurement made the value of impedance somewhat limited. To develop an alternative method to evaluate arterial mechanical properties, we analyzed the aortic pressure (AoP)-radial arterial pressure (RAP) relationship because of relative ease in obtaining peripheral pressure waveform by tonometry. In 8 patients we simultaneously recorded aortic root and radial arterial pressure waveforms. We calculated the transfer function from AoP to RAP. We then fitted the transfer function to a model of a lossless uniform elastic tube terminated with a modified Windkessel model. The fact that the model transfer function predicted AoP from RAP waveform with considerable accuracy indicated that the model represented the arterial mechanical properties well. We conclude that we can estimate the arterial mechanical properties by the pressure-pressure transfer function analysis.