Factors associated with lack of clinical improvement after vein ablation in the vascular quality initiative

BACKGROUND

Insurance companies have adopted variable and inconsistent approval criteria for chronic venous disease (CVD) treatment. Although vein ablation (VA) is accepted as the standard of care for venous ulcers, the treatment criteria for patients with milder forms of CVD remain controversial. This study aims to identify factors associated with a lack of clinical improvement (LCI) in patients with less severe CVD without ulceration undergoing VA to improve patient selection for treatment.

METHODS

We performed a retrospective analysis of patients undergoing VA for CEAP C2 to C4 disease in the Vascular Quality Initiative varicose veins database from 2014 to 2023. Patients who required intervention in multiple veins, had undergone prior interventions, or presented with CEAP C5 to C6 disease were excluded. The difference (Δ) in venous clinical severity score (VCSS; VCSS before minus after the procedure) was used to categorize the patients. Patients with a ΔVCSS of ≤0 were defined as having LCI after VA, and patients with ≥1 point decrease in the VCSS after VA (ΔVCSS ≥1) as having some benefit from the procedure and, therefore, "clinical improvement." The characteristics of both groups were compared, and multivariable regression analysis was performed to identify factors independently associated with LCI. A second analysis was performed based on the VVSymQ instrument, which measures patient-reported outcomes using five specific symptoms (ie, heaviness, achiness, swelling, throbbing pain, and itching). Patients with LCI showed no improvement in any of the five symptoms, and those with clinical improvement had a decrease in severity of at least one symptom.

RESULTS

A total of 3544 patients underwent initial treatment of CVD with a single VA. Of the 3544 patients, 2607 had VCSSs available before and after VA, and 420 (16.1%) had LCI based on the ΔVCSS. Patients with LCI were more likely to be significantly older and African American and have CEAP C2 disease compared with patients with clinical improvement. Patients with clinical improvement were more likely to have reported using compression stockings before treatment. The vein diameters were not different between the two groups. The incidence of complications was overall low, with minor differences between the two groups. However, the patients with LCI were significantly more likely to have symptoms after intervention than those with improvement. Patients with LCI were more likely to have technical failure, defined as vein recanalization. On multivariable regression, age (odds ratio [OR], 1.01; 95% confidence interval [CI], 1.00-1.02) and obesity (OR, 1.47; 95% CI, 1.09-2.00) were independently associated with LCI, as was treatment of less severe disease (CEAP C2; OR, 1.82; 95% CI, 1.30-2.56) compared with more advanced disease (C4). The lack of compression therapy before intervention was also associated with LCI (OR, 6.05; 95% CI, 4.30-8.56). The analysis based on the VVSymQ showed similar results.

CONCLUSIONS

LCI after VA is associated with treating patients with a lower CEAP class (C2 vs C4) and a lack of compression therapy before intervention. Importantly, no significant association between vein size and clinical improvement was observed.

Single-Nuclei RNA-Sequencing of the Gastrocnemius Muscle in Peripheral Artery Disease

BACKGROUND

Lower extremity peripheral artery disease (PAD) is a growing epidemic with limited effective treatment options. Here, we provide a single-nuclei atlas of PAD limb muscle to facilitate a better understanding of the composition of cells and transcriptional differences that comprise the diseased limb muscle.

METHODS

We obtained gastrocnemius muscle specimens from 20 patients with PAD and 12 non-PAD controls. Nuclei were isolated and single-nuclei RNA-sequencing was performed. The composition of nuclei was characterized by iterative clustering via principal component analysis, differential expression analysis, and the use of known marker genes. Bioinformatics analysis was performed to determine differences in gene expression between PAD and non-PAD nuclei, as well as subsequent analysis of intercellular signaling networks. Additional histological analyses of muscle specimens accompany the single-nuclei RNA-sequencing atlas.

RESULTS

Single-nuclei RNA-sequencing analysis indicated a fiber type shift with patients with PAD having fewer type I (slow/oxidative) and more type II (fast/glycolytic) myonuclei compared with non-PAD, which was confirmed using immunostaining of muscle specimens. Myonuclei from PAD displayed global upregulation of genes involved in stress response, autophagy, hypoxia, and atrophy. Subclustering of myonuclei also identified populations that were unique to PAD muscle characterized by metabolic dysregulation. PAD muscles also displayed unique transcriptional profiles and increased diversity of transcriptomes in muscle stem cells, regenerating myonuclei, and fibro-adipogenic progenitor cells. Analysis of intercellular communication networks revealed fibro-adipogenic progenitors as a major signaling hub in PAD muscle, as well as deficiencies in angiogenic and bone morphogenetic protein signaling which may contribute to poor limb function in PAD.

CONCLUSIONS

This reference single-nuclei RNA-sequencing atlas provides a comprehensive analysis of the cell composition, transcriptional signature, and intercellular communication pathways that are altered in the PAD condition.

N-acetylcysteine treatment attenuates hemodialysis access-related limb pathophysiology in mice with chronic kidney disease

The objective of the present study was to determine if treatment with N-acetylcysteine (NAC) could reduce access-related limb dysfunction in mice. Male and female C57BL6J mice were fed an adenine-supplemented diet to induce chronic kidney disease (CKD) prior to the surgical creation of an arteriovenous fistula (AVF) in the iliac vascular bundle. AVF creation significantly increased peak aortic and infrarenal vena cava blood flow velocities, but NAC treatment had no significant impact, indicating that fistula maturation was not impacted by NAC treatment. Hindlimb muscle and paw perfusion recovery and muscle capillary density in the AVF limb were unaffected by NAC treatment. However, NAC treatment significantly increased the mass of the tibialis anterior (P = 0.0120) and soleus (P = 0.0452) muscles post-AVF. There was a significant main effect of NAC treatment on hindlimb grip strength at postoperative day 12 (POD 12) (P = 0.0003), driven by significantly higher grip strength in both male (P = 0.0273) and female (P = 0.0031) mice treated with NAC. There was also a significant main effect of NAC treatment on the walking speed at postoperative day 12 (P = 0.0447), and post hoc testing revealed an improvement in NAC-treated male mice (P = 0.0091). The area of postsynaptic acetylcholine receptors (P = 0.0263) and motor endplates (P = 0.0240) was also increased by NAC treatment. Interestingly, hindlimb skeletal muscle mitochondrial oxidative phosphorylation trended higher in NAC-treated female mice but was not statistically significant (P = 0.0973). Muscle glutathione levels and redox status were not significantly impacted by NAC treatment in either sex. In summary, NAC treatment attenuated some aspects of neuromotor pathology in mice with chronic kidney disease following AVF creation.NEW & NOTEWORTHY Hemodialysis via autogenous arteriovenous fistula (AVF) is the preferred first-line modality for renal replacement therapy in patients with end-stage kidney disease. However, patients undergoing AVF surgery frequently experience a spectrum of hand disability symptoms postsurgery including weakness and neuromotor dysfunction. Unfortunately, no treatment is currently available to prevent or mitigate these symptoms. Here, we provide evidence that daily N-acetylcysteine supplementation can attenuate some aspects of limb neuromotor function in a preclinical mouse model of AVF.

Soft robot-mediated autonomous adaptation to fibrotic capsule formation for improved drug delivery

The foreign body response impedes the function and longevity of implantable drug delivery devices. As a dense fibrotic capsule forms, integration of the device with the host tissue becomes compromised, ultimately resulting in device seclusion and treatment failure. We present FibroSensing Dynamic Soft Reservoir (FSDSR), an implantable drug delivery device capable of monitoring fibrotic capsule formation and overcoming its effects via soft robotic actuations. Occlusion of the FSDSR porous membrane was monitored over 7 days in a rodent model using electrochemical impedance spectroscopy. The electrical resistance of the fibrotic capsule correlated to its increase in thickness and volume. Our FibroSensing membrane showed great sensitivity in detecting changes at the abiotic/biotic interface, such as collagen deposition and myofibroblast proliferation. The potential of the FSDSR to overcome fibrotic capsule formation and maintain constant drug dosing over time was demonstrated in silico and in vitro. Controlled closed loop release of methylene blue into agarose gels (with a comparable fold change in permeability relating to 7 and 28 days in vivo) was achieved by adjusting the magnitude and frequency of pneumatic actuations after impedance measurements by the FibroSensing membrane. By sensing fibrotic capsule formation in vivo, the FSDSR will be capable of probing and adapting to the foreign body response through dynamic actuation changes. Informed by real-time sensor signals, this device offers the potential for long-term efficacy and sustained drug dosing, even in the setting of fibrotic capsule formation.

Dynamic actuation enhances transport and extends therapeutic lifespan in an implantable drug delivery platform

Fibrous capsule (FC) formation, secondary to the foreign body response (FBR), impedes molecular transport and is detrimental to the long-term efficacy of implantable drug delivery devices, especially when tunable, temporal control is necessary. We report the development of an implantable mechanotherapeutic drug delivery platform to mitigate and overcome this host immune response using two distinct, yet synergistic soft robotic strategies. Firstly, daily intermittent actuation (cycling at 1 Hz for 5 minutes every 12 hours) preserves long-term, rapid delivery of a model drug (insulin) over 8 weeks of implantation, by mediating local immunomodulation of the cellular FBR and inducing multiphasic temporal FC changes. Secondly, actuation-mediated rapid release of therapy can enhance mass transport and therapeutic effect with tunable, temporal control. In a step towards clinical translation, we utilise a minimally invasive percutaneous approach to implant a scaled-up device in a human cadaveric model. Our soft actuatable platform has potential clinical utility for a variety of indications where transport is affected by fibrosis, such as the management of type 1 diabetes.

Drug delivery implants suffer from diminished release profiles due to fibrous capsule formation over time. Here, the authors use soft robotic actuation to modulate the immune response of the host to maintain drug delivery over the longer-term and to perform controlled release in vivo.

Outcomes of EVAR Conversion in Octogenarians Treated at a High-Volume Aorta Center

INTRODUCTION

Endovascular aortic aneurysm repair(EVAR) is the dominant treatment strategy for infrarenal abdominal aortic aneurysms(AAA) but is especially preferred among octogenarian(age ≥80-years) patients due to concerns surrounding comorbidity severity and physiological frailty. Correspondingly, EVAR failure resulting in subsequent open conversion(EVAR-c) has been increasingly reported in older patients but there is a paucity of literature focusing on outcomes in this subgroup. The purpose of this analysis was to evaluate our experience with EVAR-c in octogenarians(≥80-years) compared to younger patients(age <80-years).

METHODS

A retrospective review of all non-mycotic EVAR-c procedures(2002-2020) at a single high-volume academic hospital with a dedicated aorta center(https://www.uf-health-aortic-disease-center) was performed. Patients(n=162) were categorized into octogenarian(age ≥80; n=43) and non-octogenarian(age<80; n=119) cohorts and subsequently compared. The primary end-point was 30-day mortality. Secondary end-points included complications, 90-day mortality, and overall survival. Cox regression determined effects of selected covariates on mortality risk. Kaplan-Meier methodology estimated survival.

RESULTS

No difference in pre-admission EVAR re-intervention rates was present(octogenerians-42% vs. non-octogenerians-43%;p=1) although time to first re-intervention was greater in octogenarians(41 vs. non-octogenarians, 15-months;p=.01). Concordantly, time to EVAR-c was significantly longer among octogenarian patients(61 vs. non-octogenarians, 39-months;p<.01). No difference in rupture presentation was evident(14% vs. 10%;p=.6); however, elective EVAR-c occurred less frequently(octogenerians-42% vs. non-octogenerians-59%;p=.07). AAA diameter was significantly larger for elective octogenarian EVAR-c(7.8±1.9cm vs. non-octogenarians, 7.0±1.5cm;p=.02) and type 1a endoleak was the most common indication overall(58%;n=91). Among all presentations, a trend in higher 30-day mortality was evident for octogenarian patients(16% vs. non-octogenarians, 7%;p=.06). Similarly 90-day mortality was greater among octogenarians(26% vs. non-octogenarians, 10%;p=.02). However, incidence of any complication(56% vs. 49%;p=.5), readmission(12% vs. 6%;p=.3), unplanned re-operation(10% vs. 5%;p=.5) and LOS(11 vs. 9 days;p=.3) was not significantly different. Age ≥80 was predictive of short-term mortality after non-elective but not elective cases; however, increasing comorbidity number, non-elective admission and renal/mesenteric revascularization had the strongest association with mortality risk. One- and three-year survival was not different between groups when comparing all patients after the first 90-days postoperatively.

CONCLUSION

Although higher unadjusted peri-operative mortality occurred among octogenarian patients, risk-adjusted elective outcomes were comparable to younger EVAR-c subjects when treated at a high-volume aortic surgery center. This underscores the importance of appropriate patient selection and modulation of operative complexity when feasible to achieve optimal results. Providers caring for octogenarian patients with EVAR failure should consider timely elective referral to high-volume aorta centers to reduce resource utilization and frequency of non-elective presentations.

Additive Manufacturing of Multi-Scale Porous Soft Tissue Implants That Encourage Vascularization and Tissue Ingrowth

Medical devices, such as silicone-based prostheses designed for soft tissue implantation, often induce a suboptimal foreign-body response which results in a hardened avascular fibrotic capsule around the device, often leading to patient discomfort or implant failure. Here, it is proposed that additive manufacturing techniques can be used to deposit durable coatings with multiscale porosity on soft tissue implant surfaces to promote optimal tissue integration. Specifically, the "liquid rope coil effect", is exploited via direct ink writing, to create a controlled macro open-pore architecture, including over highly curved surfaces, while adapting atomizing spray deposition of a silicone ink to create a microporous texture. The potential to tailor the degree of tissue integration and vascularization using these fabrication techniques is demonstrated through subdermal and submuscular implantation studies in rodent and porcine models respectively, illustrating the implant coating's potential applications in both traditional soft tissue prosthetics and active drug-eluting devices.

Implantable Therapeutic Reservoir Systems for Diverse Clinical Applications in Large Animal Models

Regenerative medicine approaches, specifically stem cell technologies, have demonstrated significant potential to treat a diverse array of pathologies. However, such approaches have resulted in a modest clinical benefit, which may be attributed to poor cell retention/survival at the disease site. A delivery system that facilitates regional and repeated delivery to target tissues can provide enhanced clinical efficacy of cell therapies when localized delivery of high doses of cells is required. In this study, a new regenerative reservoir platform (Regenervoir) is described for use in large animal models, with relevance to cardiac, abdominal, and soft tissue pathologies. Regenervoir incorporates multiple novel design features essential for clinical translation, with a focus on scalability, mechanism of delivery, fixation to target tissue, and filling/refilling with a therapeutic cargo, and is demonstrated in an array of clinical applications that are easily translated to human studies. Regenervoir consists of a porous reservoir fabricated from a single material, a flexible thermoplastic polymer, capable of delivering cargo via fill lines to target tissues. A radiopaque shear thinning hydrogel can be delivered to the therapy reservoir and multiple fixation methods (laparoscopic tacks and cyanoacrylate bioadhesive) can be used to secure Regenervoir to target tissues through a minimally invasive approach.

An actuatable soft reservoir modulates host foreign body response

The performance of indwelling medical devices that depend on an interface with soft tissue is plagued by complex, unpredictable foreign body responses. Such devices-including breast implants, biosensors, and drug delivery devices-are often subject to a collection of biological host responses, including fibrosis, which can impair device functionality. This work describes a milliscale dynamic soft reservoir (DSR) that actively modulates the biomechanics of the biotic-abiotic interface by altering strain, fluid flow, and cellular activity in the peri-implant tissue. We performed cyclical actuation of the DSR in a preclinical rodent model. Evaluation of the resulting host response showed a significant reduction in fibrous capsule thickness (P = 0.0005) in the actuated DSR compared with non-actuated controls, whereas the collagen density and orientation were not changed. We also show a significant reduction in myofibroblasts (P = 0.0036) in the actuated group and propose that actuation-mediated strain reduces differentiation and proliferation of myofibroblasts and therefore extracellular matrix production. Computational models quantified the effect of actuation on the reservoir and surrounding fluid. By adding a porous membrane and a therapy reservoir to the DSR, we demonstrate that, with actuation, we could (i) increase transport of a therapy analog and (ii) enhance pharmacokinetics and time to functional effect of an inotropic agent. The dynamic reservoirs presented here may act as a versatile tool to further understand, and ultimately to ameliorate, the host response to implantable biomaterials.

A novel platelet lysate hydrogel for endothelial cell and mesenchymal stem cell-directed neovascularization

Mesenchymal stem cells (MSC) hold promise in promoting vascular regeneration of ischemic tissue in conditions like critical limb ischemia of the leg. However, this approach has been limited in part by poor cell retention and survival after delivery. New biomaterials offer an opportunity to localize cells to the desired tissue after delivery, but also to improve cell survival after delivery. Here we characterize the mechanical and microstructural properties of a novel hydrogel composed of pooled human platelet lysate (PL) and test its ability to promote MSC angiogenic activity using clinically relevant in vitro and in vivo models. This PL hydrogel had comparable storage and loss modulus and behaved as a viscoelastic solid similar to fibrin hydrogels despite having 1/4-1/10th the fibrin content of standard fibrin gels. Additionally, PL hydrogels enabled sustained release of endogenous PDGF-BB for up to 20days and were resistant to protease degradation. PL hydrogel stimulated pro-angiogenic activity by promoting human MSC growth and invasion in a 3D environment, and enhancing endothelial cell sprouting alone and in co-culture with MSCs. When delivered in vivo, the combination of PL and human MSCs improved local tissue perfusion after 8days compared to controls when assessed with laser Doppler perfusion imaging in a murine model of hind limb ischemia. These results support the use of a PL hydrogel as a scaffold for MSC delivery to promote vascular regeneration.

STATEMENT OF SIGNIFICANCE

Innovative strategies for improved retention and viability of mesenchymal stem cells (MSCs) are needed for cellular therapies. Human platelet lysate is a potent serum supplement that improves the expansion of MSCs. Here we characterize our novel PL hydrogel's desirable structural and biologic properties for human MSCs and endothelial cells. PL hydrogel can localize cells for retention in the desired tissue, improves cell viability, and augments MSCs' angiogenic activity. As a result of these unique traits, PL hydrogel is ideally suited to serve as a cell delivery vehicle for MSCs injected into ischemic tissues to promote vascular regeneration, as demonstrated here in a murine model of hindlimb ischemia.

The Role of Osteopontin in Recovery from Hind Limb Ischemia

Objective— Osteopontin (OPN) is a highly phosphorylated extracellular matrix glycoprotein that is involved in a diversity of biological processes. In the vascular wall, OPN is produced by monocytes/macrophages, endothelial cells, and smooth muscle cells, and it is thought to mediate adhesion, migration, and survival of these cell types. In this study, we hypothesized that OPN plays a critical role in recovery from limb ischemia.

Methods and Results— We induced hind limb ischemia in wild-type and OPN −/− mice. OPN −/− mice exhibited significantly delayed recovery of ischemic foot perfusion as determined by LDPI, impaired collateral vessel formation as measured using micro-CT, and diminished functional capacity of the ischemic limb. In the aortic ring assay, normal endothelial cell sprouting was found in OPN −/− mice. However, OPN −/− peritoneal monocytes/macrophages were found to possess significantly reduced migration in response to chemoattraction.

Conclusions— This study provides evidence that a definitive biological role exists for OPN during ischemic limb revascularization, and we have suggested that this may be driven by impaired monocyte/macrophage migration in OPN −/− mice. These findings provide the first in vivo evidence that OPN may be a key regulator in postnatal vascular growth.

Oxygen metabolism during liver transplantation: the effect of dichloroacetate

Dichloroacetate (DCA) stimulates pyruvate dehydrogenase (PDH), accelerating recovery of the postischemic heart. Because DCA also stimulates hepatic PDH, it may facilitate graft recovery during liver transplantation (OLT). Hepatic removal and replacement during OLT produce major changes in O2 consumption (VO2), and return of baseline VO2 has been used to index early graft function. We examined the effect of DCA on O2 metabolism during OLT. Forty patients received DCA 80 mg/kg intravenously in divided doses, and 40 served as controls. Serial measurements were made for body temperature, hemodynamics, O2 metabolic indices, and plasma substrate and hormonal concentrations. Oxygen delivery (DO2I) and consumption (VO2I) indices were calculated. Patients exhibited stable hemodynamics, with similar fluid and blood product requirements. Compared with the dissection stage, DO2I and VO2I were decreased during the anhepatic stage (31% and 36%, respectively), then returned to dissection stage values soon after portal vein unclamping. Temperature decreased during the anhepatic stage and returned toward dissection stage value after graft perfusion. DCA reduced lactic acidosis and NaHCO3 use but did not alter hemodynamics or measures of O2 metabolism or body temperature. VO2 is decreased during the anhepatic stage largely due to loss of hepatic metabolism. Restoration of VO2 by 30 min after portal vein unclamping reflects rapid recovery of O2 metabolism by the graft liver, but DCA does not accelerate recovery of VO2. DCA does not seem to facilitate early graft hepatic function as indexed by VO2.

IMPLICATIONS

We evaluated whether dichloroacetate, which stimulates pyruvate dehydrogenase, can accelerate recovery of graft liver hepatic function during liver transplantation, as indexed by oxygen consumption. We found that despite evidence that it activated pyruvate dehydrogenase, dichloroacetate did not affect recovery of transplanted liver function.

Amelioration of lactic acidosis with dichloroacetate during liver transplantation in humans

BACKGROUND

Marked lactic acidosis occurs during orthotopic liver transplantation (OLT), especially during the anhepatic phase. Current standard therapy is NaHCO3, although it may exacerbate intracellular acidosis, increase plasma lactate, and contribute to hypernatremia. Alternatively, dichloroacetate (DCA) stimulates pyruvate oxidation in vivo, reduces plasma lactate, and moderates intracellular acidosis. The aims of this study were to test the efficacy of DCA to control lactic acidosis, reduce the NaHCO3 requirement and incidence of hypernatremia, and stabilize perioperative acid-base homeostasis. Others aims were to examine the DCA pharmacokinetic profile during OLT and the role of lactate metabolism in OLT-associated hyperglycemia.

METHODS

Patients (n = 66) for OLT were divided into two equal groups to receive or not receive DCA during OLT. DCA 40 mg.kg-1 was infused over 60 min after induction of anesthesia and 4 h later. Plasma DCA concentration was measured by gas chromatography-mass spectroscopy, and pharmacokinetics were assessed by a one-compartment model. Serial arterial blood gases, lactate, Na+, glucose, and hemodynamic measurements were compared, as were intraoperative utilization of blood products, CaCl2, and NaHCO3.

RESULTS

Plasma DCA concentration was maintained between 0.28 and 1.18 mM during OLT, with peak concentrations of 0.73 +/- 0.06 (mean +/- SE) and 1.18 +/- 0.09 mM, respectively after the first and second doses. In control patients, plasma lactate was 1.07 +/- 0.04 at baseline and 1.20 +/- 0.06 before incision and reached a peak of 7.30 +/- 0.41 mM after graft reperfusion. In DCA-treated patients, the respective values were 1.07 +/- 0.06 (difference not significant), 0.63 +/- 0.05 (P < 0.001), and 3.39 +/- 0.20 (P < 0.001) mM. Intraoperative changes in arterial blood pH, HCO3(-1), and base excess were comparable though less marked in DCA-treated patients, whose NaHCO3 requirement was reduced (0.59 +/- 0.36 vs. 2.83 +/- 0.53 mEq.kg-1 in control patients, P < 0.001). There was no difference between groups in requirements for CaCl2 or blood products, in intraoperative hemodynamics, in duration of the surgical stages, or in graft ischemia times. Twelve control and 4 DCA-treated patients exhibited a plasma Na+ concentration > 145 mEq/1 at completion of surgery (P < 0.05). Hyperglycemia was not attenuated by DCA despite decreased plasma lactate concentration. Sixteen and 28 h after graft reperfusion, when plasma DCA had been eliminated, plasma lactate and degree of metabolic alkalosis did not differ between groups.

CONCLUSIONS

DCA safely and effectively attenuated lactic acid accumulation and moderated acidosis during OLT. DCA decreased the requirement for NaHCO3 therapy and the incidence of hypernatremia. OLT-associated hyperglycemia did not result from lactate-induced stimulation of hepatic gluconeogenesis. Postoperative metabolic alkalosis was not substantially influenced by lactate metabolism.

The hemodynamic effects of intraoperative injection of muromonab CD3

During anesthesia 5 mg of muromonab CD3 (OKT3), an anti-CD3 monoclonal antibody, was administered prophylactically to twelve patients undergoing cadaveric renal transplantation. Preoperatively, all patients were at or near their dry body weights. Methylprednisolone 500 mg on call to or in the operating room, azathioprine 2 mg kg-1 and diphenhydramine 50 mg were administered intraoperatively to reduce the probability and severity of reported effects of OKT3. After induction of anesthesia, the patients were monitored for changes in cardiovascular variables for up to 120 min after OKT3 administration. All patients had uneventful anesthetic courses. Analysis of variance showed no significant changes from pre-OKT3 administration in heart rate, mean blood pressure, mean pulmonary artery pressure, central venous pressure (CVP), pulmonary capillary wedge pressure (PCWP), and pulmonary vascular resistance (PVRI). CVP values were a reliable indicator of PCWP with the correlation coefficient of CVP to PCWP or r = 0.78 (P < 0.00005) and PCWP = .89 x CVP + 3.78. Cardiac index (CI) increased 22% at 105 min (P < 0.05). Systemic vascular resistance index (SVRI) decreased 21% at 105 min (P < 0.05). SVRI was increased 16% at 10 min post-OKT3 (P < 0.05). All of these statistically significant values were within acceptable clinical limits. Euvolemic cadaveric renal transplant recipients receiving prophylactic steroids and diphenhydramine may receive OKT3 in the operating room for induction immunosuppression without any appreciable risk of cardiovascular compromise.