Paul A Armstrong

University of South Florida, Tampa, Florida, United States

Are you Paul A Armstrong?

Claim your profile

Publications (41)74.05 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Most clinicians feel that treatment for patients with acute primary axillosubclavian vein thrombosis ("effort thrombosis") is catheter-directed thrombolysis followed by thoracic outlet decompression. Several investigators feel that first rib resection is not indicated in every case. No randomized data exist to answer this question. A Medline search was done using the terms "Paget-Schroetter syndrome," "upper extremity DVT," "first rib resection," "effort thrombosis," and "primary upper extremity thrombosis," with thrombolysis used as an "AND" term. We also specifically explored references cited to support either side of this argument in the past. Analysis was limited to patients 18 years of age or greater with symptoms of 14 days' duration or less undergoing thrombolysis for primary axillosubclavian vein thrombosis. Those studies that did not report follow-up, duplicate series from the same institution, and those in which patients were stented were excluded. Results were analyzed on an intent-to-treat basis, with groups assigned according to each authors' prospectively described algorithm. Twelve series were included. Patients were divided into three groups according to treatment after thrombolysis: first rib resection (FRR; 448 patients), first rib resection plus endovenous balloon venoplasty (FRR+PLASTY; 68 patients), and those with no further intervention after thrombolysis (RIB NOT REMOVED; 168 patients). Symptom relief at last follow-up was significantly more likely in the FRR (95%) and FRR+PLASTY (93%) groups than in the RIB NOT REMOVED (54%) group (both <.0001) as was patency (98%, 86%, and 48%, respectively; both <.0001 vs RIB NOT REMOVED). Over 40% of patients in the RIB NOT REMOVED group eventually required rib resection for recurrent symptoms. No differences in symptom free rates were seen when comparing FRR to FRR+PLASTY. In patients with acute effort thrombosis who undergo thrombolysis, permanent symptom relief and long-term patency are more likely to be achieved in patients who undergo first rib resection with or without endovenous balloon venoplasty than those whose rib is left intact. Copyright © 2015 Elsevier Inc. All rights reserved.
    No preview · Article · May 2015 · Annals of Vascular Surgery
  • [Show abstract] [Hide abstract]
    ABSTRACT: A substantial number of patients with autologous arteriovenous fistulas (AVF) develop diffuse aneurysmal degeneration, which frequently interferes with successful access. These AVF are often deemed unsalvageable. We hypothesize that long segment plication in these patients can be performed safely with acceptable short-term AVF salvage rates. We reviewed a prospectively maintained database to identify all patients with extensive AVF aneurysmal disease operated on for this problem. Thirty-five patients, 25 (71%) male and 10 (29%) female were operated upon between July 2012 and January 2014. AVFs included 23 (66%) brachiocephalic, 5 (14%) radiocephalic, and 7 brachiobasilic (20%) fistulae (one first stage only but in use). The cohort had one or a combination of local pain, arm edema, cannulation issue, recurrent thrombosis, dysfunctional during dialysis, or extreme tortuousity. Time range for AVF creation to consultation ranged from 3 months to 11 years.All underwent long segment plication over a 20Fr Bougie with or without segmental vein resection; 3 underwent concomitant first rib resection for costoclavicular stenosis. 21 patients had tunneled catheter placement for use while healing, while 13 were allowed segmental use of their AVF during the perioperative period (one patient was not yet on dialysis). Early in our experience AVF were left under the wound, while all but one repaired since early 2013 were left under a lateral flap.All patients were followed by clinical exam and duplex. In the 30 day postoperative period, 2 AVF (5.7%) became infected requiring excision, 2 occluded (5.7%), one day 1 and the other at 24 days out, 1 patient developed steal and required DRIL one week post operatively, and 1 patient died, unrelated to his surgery. Postoperative functional primary patency was 88% (30 of 34). Of the patients needing temporary access catheter, mean time to first fistula use was 44 days. No wound or bleeding complications have occurred in repaired AVF left under skin flaps. In this group of patients whose access was threatened by diffuse aneurysmal degeneration, long-segment placation allowed salvage of 88% of fistulae with relatively low morbidity. Fewer complications are associated by covering the revised fistula with intact skin. Copyright © 2015 Elsevier Inc. All rights reserved.
    No preview · Article · Mar 2015 · Annals of Vascular Surgery
  • Aurelia Calero · Paul A. Armstrong
    [Show abstract] [Hide abstract]
    ABSTRACT: Venous invasion is a common characteristic of renal cell carcinoma (RCC) manifesting as tumor thrombus with possible extension into the renal vein, and in extensive cases the thrombus can extend from renal vein to the right atrium. Presently, cytoreductive nephrectomy and tumor thrombectomy are the foundation for improving quality of life and survival in the treatment of RCC, therefore there has emerged a role for a vascular specialist to become an integral part of operative planning and therapy.
    No preview · Article · Sep 2014 · Seminars in Vascular Surgery
  • [Show abstract] [Hide abstract]
    ABSTRACT: To determine whether the formation of an integrated vascular surgery residency (0 + 5) has negatively impacted the case volume and diversity of the vascular surgery fellows (5 + 2) and chief general surgeons at the same institution. Operative data from the vascular integrated (0 + 5), independent (5 + 2), and general surgery residencies at a single institution were retrospectively reviewed and analyzed to determine vascular surgery case volumes from 2006-2012. National operative data (Residency Review Committee) were used for comparison of diversity and volume. Standard statistical methods were applied. During this period, the 5 + 2 fellows at our institution performed on average 741 (range, 554-1002) primary cases and 1091 (range, 844-1479) combined primary and secondary cases for the 2-year fellowship. Our integrated residency began in July 2007. Our fellows' primary case volumes remained relatively stable between 2006 and 2011, with a 4% increase in the number of cases, although their total (primary and secondary) case volumes fell 15%; by comparison, the equivalent national 50th percentile rates rose 16% during this time frame. Our institution's general surgery residents performed an average of 116 (range, 56-221) vascular cases individually during their 5-year residency from 2005-2011. From 2006-2011, the total case volume fell only 5%, while the national 50th percentile rate fell 24%. Across all years, however, resident and fellow volumes both continue to be above Accreditation Council for Graduate Medical Education minimum requirements, and the major vascular case volume at our institution in all groups studied remained statistically greater than or equal to the national 50th percentile of cases. Our first integrated resident to graduate finished in June 2012 with 931 total vascular cases and 249 general surgery cases for a total operative experience of 1180 cases during the 5-year residency. Finally, after an 8-year period (2003-2010) in which none of our general surgery residents pursued vascular training, 1 resident in each of the 2011, 2012, and 2013 graduating years has now done so. At our institution, the introduction of a 0 + 5 vascular residency has correlated with a modest drop (15%) in overall case volume for the 5 + 2 fellows, but the number of primary cases have actually increased slightly and they continue to meet or exceed Accreditation Council for Graduate Medical Education requirements and national 50th percentile rates. General surgery residents' vascular volumes, by contrast, have remained stable, and interest in vascular surgery by residents has increased. Our integrated vascular residents are projected to exceed the fellows' 50th percentile case volume and diversity targets during their residency experience.
    No preview · Article · Oct 2013 · Annals of Vascular Surgery

  • No preview · Article · Apr 2013 · The Journal of Urology
  • Paul A. Armstrong · Alexis Powell · Dennis F. Bandyk
    [Show abstract] [Hide abstract]
    ABSTRACT: The outcome of carotid interventions depends on technical precision of the arterial repair which can be assessed accurately using ultrasound imaging. Following carotid endarterectomy, duplex ultrasound provides both anatomic (real-time B-mode imaging) and hemodynamic (pulsed Doppler spectral analysis) assessment of the repair, allowing detection of residual stenosis, lumen debris, plaque dissection, and verification of normal low resistance flow in the distal internal carotid artery. Intravascular ultrasound is suited for monitoring carotid stent-angioplasty as the over-the-wire catheter provides high-resolution real-time imaging of the extracranial carotid artery for vessel diameter measurements, selection of stent landing zones, and alerting the interventionist to incomplete stent expansion (residual stenosis) or other abnormalities such as lumen thrombus or vessel dissection proximal or distal to the stent. Intraprocedural ultrasound imaging will identify abnormalities that should be corrected in approximately 5–10% of cases. Detection and immediate repair of detected abnormalities is associated with clinical outcomes similar to reconstructions judged “normal” on initial ultrasound assessment, including perioperative neurologic events and reintervention for restenosis.
    No preview · Chapter · Jan 2013
  • Source

    Full-text · Article · Dec 2012 · Journal of Vascular Surgery
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background This report details the experience of a multidisciplinary surgical team in the management of stage III and stage IV renal cell carcinoma (RCC) with concomitant inferior vena cava (IVC) tumor thrombus. Methods A retrospective inquiry of our vascular database from 2003 to 2012 identified 55 surgical cases of stage III (n = 40) and stage IV (n = 15) RCC presenting with IVC tumor thrombus. Tumor characteristics and IVC tumor thrombus were evaluated by clinical staging and postoperative pathology staging. Patient demographics and surgical reconstruction are detailed. Cancer-specific outcomes consisted of oncologic surveillance with computed tomography or magnetic resonance imaging. A Clavien-Dindo classification of early (<30 days) complications and mortality was recorded, including a review of secondary surgical interventions. Results According to the Novick classification of IVC tumor thrombus, there were 10 supradiaphragmatic (level IV), 20 intrahepatic (level III), and 25 infrahepatic (level II or I) tumor thrombi. Vena cava reconstruction was completed in 54 patients (98%), with one patient deemed unresectable. Vena cava control required cardiac bypass (n = 10), venovenous bypass (n = 4), or infrahepatic IVC control (n = 40). Reconstruction of the IVC was completed with two prosthetic interposition grafts for one stage IV thrombus and one stage III thrombus; two patch repairs were done for stage III thrombus, and there were 50 primary IVC repairs. All other IVC reconstructions were patent at a mean follow-up of 23 months. A single asymptomatic patient with primary IVC repair had estimated 30% IVC narrowing but no other measurable stenosis as detected by postoperative imaging. Three patients required reoperation (two for surgical site bleeding, one for small bowel fistula). Early surgical complications included Clavien-Dindo grades I (n = 3), II (n = 6), IIIa (n = 2), IIIb (n = 3), and V (n = 2). Regional retroperitoneal or distant recurrent RCC occurred in 26 patients (48%); a single patient demonstrating recurrent IVC tumor thrombus at 8 months required secondary IVC thrombectomy. All patients with tumor invasion of the IVC wall developed recurrent RCC, and no patient survived beyond 5 years. Early mortality was 3.6% (n = 2), with 27 patients (49%) dying within 24 months, resulting in an overall mortality for the cohort of 80% (n = 44) as established on routine regular postoperative surveillance. Conclusions A multidisciplinary approach for the management of advanced RCC and IVC tumor thrombus helps optimize outcomes. Primary IVC repairs are possible in most patients, and IVC patency is good. Recurrent tumor thrombus rates are low; however, RCC tumor recurrence and mortality are high, especially among patients with advanced cancer with IVC wall invasion.
    Preview · Article · Dec 2012
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: What's known on the subject? and What does the study add? Historically, the surgical management of renal tumours with intravascular tumour thrombus has been associated with high morbidity and mortality. In addition, few cases are treated, and typically at tertiary care referral centres, hence little is known and published about the ideal surgical management of such complex cases. The present comprehensive review details how a multidisciplinary surgical approach to renal tumours with intravascular tumour thrombus can optimise patient outcomes. Similarly, we have developed a treatment algorithm in this review that can be used in the surgical planning of such cases.
    Full-text · Article · Apr 2012 · BJU International
  • [Show abstract] [Hide abstract]
    ABSTRACT: To compare the accuracy of inferior vena cava (IVC) filter placement using a bedside technique guided by intravascular ultrasound (IVUS) with a concurrent experience of filter deployment with fluoroscopic venogram imaging. From November 2006 to December 2009, 195 consecutive IVC filters were placed to prevent pulmonary embolism in 120 high-risk patients without lower limb deep vein thrombosis (DVT) and 75 patients with DVT and anticoagulation contraindications. Filter insertion techniques included bedside IVUS-guided (n = 97) and fluoroscopic-guided (n = 98) procedures. Before mid-2008, 2 bedside IVUS-guided protocols were used evolving from a single-puncture, pullback technique (n = 48), in which the measured distance from the venous access site to the IVC landing zone then allowed a calibrated reinsertion of a 7F delivery sheath and filter deployment. After mid-2008, a single puncture 8F sheath technique (n = 48) using IVUS to position the delivery sheath tip within the IVC landing zone without catheter or sheath measurement or reinsertion was used. Venous access was via the right femoral (84 IVUS and 56 fluoroscopy), left femoral (10 IVUS and 16 fluoroscopy), or right internal jugular vein (3 IVUS and 26 fluoroscopy). The 3 filter insertion techniques were compared for "optimal" IVC placement defined as the filter positioning between L1 and L4 vertebrae with tilt <15° based on postprocedure abdominal x-rays or venography. Filter malposition occurred with 6% (6 of 97) bedside IVUS-guided procedures with no malpositions during fluoroscopic imaging. Malposition was lower with the evolved sheath (4%, 2 of 48) compared with the earlier pullback (8%, 4 of 48) insertion technique (P = .03). The incidence of the filter malposition during IVUS-guided deployment was highest using left femoral access (4 of 10) compared with right femoral (2 of 84) or internal jugular (0 of 3) vein access (P < .01). Filter tilt occurred more after IVUS-guided procedure (10 of 97) than fluoroscopic procedure (3 of 98; P = .05) and was most frequent for left femoral access (5 of 10 IVUS and 1 of 16 fluoroscopy; P < .01) and was not related to filter type (P = .13). Our current bedside IVUS-guided IVC filter technique using a single venous puncture and single sheath positioning has improved the placement accuracy. Left femoral venous access should be avoided to minimize the occurrence of filter malpositioning and tilt.
    No preview · Article · Apr 2012 · Vascular and Endovascular Surgery
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The management of a post-chemotherapy retroperitoneal mass secondary to testicular cancer can present a surgical challenge when involving adjacent organs or major vascular structures. We present the first video of a retroperitoneal lymph node dissection (RPLND) with IVC (inferior vena cava) thrombectomy, caval wall resection resulting from metastatic non-seminomatous germ cell testis (NSGCT) cancer. In this surgical video, we highlight important surgical considerations in the management of a postchemotherapy retroperitoneal mass with direct IVC wall invasion and level 2 thrombus in such a patient. A 34 year old man underwent a right inguinal orchiectomy for a mixed NSGCT (embryonal, yolk sac, and teratoma components) and elevated serum tumor markers. He underwent systemic chemotherapy (BEP regimen x 4 cycles) with subsequent near normalization of tumor markers. His post-chemotherapy imaging revealed a 6 cm residual retroperitoneal mass with a level 2 IVC tumor thrombus and suspected direct infrarenal IVC wall invasion from the mass. The patient underwent an open post-chemotherapy RPLND, IVC thrombectomy, IVC resection and grafting. The final pathology report of the retroperitoneal mass revealed teratoma with no viable germ cell tumor elements and negative surgical margins. His intra-operative and post-operative stages were unremarkable with his IVC graft remaining patent and no evidence of disease recurrence at last follow-up. We present the first surgical video of a post-chemotherapy RPLND with IVC thrombectomy, caval wall resection and grafting for metastatic NSGCT. The final pathology report of teratoma with no viable tumor highlights the local vascular invasive potential of such pathology.
    Full-text · Article · Jan 2012 · International braz j urol: official journal of the Brazilian Society of Urology
  • P. Spiess · T. Kim · T. Kurian · W. Sexton · J. Powsang · P. Armstrong · D. Mangar

    No preview · Article · Sep 2011 · Urology
  • Source

    Full-text · Article · Dec 2010 · Journal of Vascular Surgery
  • Paul A. Armstrong · Dennis F. Bandyk
    [Show abstract] [Hide abstract]
    ABSTRACT: An accurate diagnosis of lower extremity peripheral artery disease (PAD) can usually be established based on the clinical history, vascular examination including pulse palpation, and Doppler survey of the femoral and pedal arteries.With the development of symptomatic PAD, i.e., disabling claudication, critical limb ischemia (ischemic rest pain, tissue loss), or peripheral aneurysmal disease, more detailed vascular testing is necessary for disease management. Peripheral arterial testing is best performed in an accredited facility by certified technical personnel and physicians experienced in test interpretation. Measurement of limb blood pressure in conjunction with duplex mapping of the arterial tree should be performed to assess disease location and severity. Duplex ultrasound scanning provides hemodynamic and anatomic information at no risk to the patient and ensures an accurate diagnosis.1–4 Based on disease location and morphology, a decision to proceed with endovascular or surgical intervention is possible.5–9 Other vascular imaging modalities [contrast arteriography, computed tomography (CT) angiography, magnetic resonance angiography (MRA)] do not provide hemodynamic information essential for the evaluation of symptomatic PAD, and formulating an individualized treatment plan.
    No preview · Chapter · Mar 2010
  • D F Bandyk · PA Armstrong
    [Show abstract] [Hide abstract]
    ABSTRACT: Intravascular ultrasound (IVUS) provides high-resolution vessel imaging and has been shown to improve clinical outcomes when used to assess the technical result of peripheral angioplasty procedures. Our vascular group compared anatomic and clinical outcomes of carotid artery stent-angioplasty (CAS) performed with angiogram monitoring alone, or in combination with IVUS imaging to select stent/balloon diameter and interrogate stent deployment region for residual stenosis. A retrospective review of our carotid stent registry (N=306) identified 220 CAS procedures performed with either a digital C-arm fluoroscopy alone (N=110) or in conjunction with IVUS (N=110) with at least 6-month of clinical follow-up. Outcome measures of procedure time, angioplasty balloon diameter, contrast dye volume, Duplex surveillance testing for recurrent stenosis, and procedure event (death, cardiac, neurologic) rates were compared to assess the risks and benefits of IVUS. All procedures utilized a cerebral protection device deployed prior to IVUS imaging. Procedure times were similar, but IVUS usage resulted in lower (P<0.05) contrast agent volumes due to fewer angiogram runs for stent sizing and verification of adequate stent deployment. IVUS imaging resulted in the use of larger diameter balloons (typically 6 mm) for final stent angioplasty based on distal internal carotid artery (ICA) dia measurements, and identified (P<0.01) more residual stent abnormalities (N=12, 11%) versus CAS with angiogram assessment alone (N=2, 1.8%). No procedural or 30-day cardiac events or deaths occurred. The overall stroke rate was 0.9%; two events (stroke-1; reperfusion injury-1) in the angio+IVUS group (1.8%) and none in the angio alone group. Duplex ultrasound surveillance following CAS demonstrated a higher (P<0.01) incidence of >50% diameter-reducing in-stent stenosis in the angio alone group (11% vs 7% at 1 month ; 24% vs 6% at last surveillance; mean 36 moontha; range: 6-66 months). The quality control of the CAS procedure was enhanced by IVUS imaging which directed stent /balloon sizing and was more accurate than angiography in confirming adequate stent expansion. No IVUS related adverse events occurred. Based on the anatomic information provided by IVUS, larger diameter angioplasty balloons were used which correlated with less residual stenosis after CAS based on duplex ultrasound testing.
    No preview · Article · Dec 2009 · The Journal of cardiovascular surgery
  • Source

    Full-text · Article · Dec 2009 · Journal of Vascular Surgery
  • [Show abstract] [Hide abstract]
    ABSTRACT: The authors report the microbiology and outcomes following an individualized treatment algorithm for extracavitary (EC) prosthetic graft infection, including the use of graft preservation and in situ graft replacement techniques. A retrospective 8-year review of 87 patients treated for EC prosthetic graft infections was carried out. The treatment algorithm included culture-specific antibiotic therapy, surgical site debridement with antibiotic bead placement, selected graft preservation with muscle flap coverage, or graft excision with in situ conduit replacement. Outcomes measured included death, limb loss, and recurrent infection. It was found that present-day management of EC prosthetic graft infections is associated with lower mortality and morbidity despite changes in microbiology and the increased application of graft preservation and in situ grafting treatments.
    No preview · Article · Oct 2008 · Vascular and Endovascular Surgery
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Controversy regarding the efficacy of duplex ultrasound surveillance after infrainguinal vein bypass led to an analysis of patient and bypass graft characteristics predictive for development of graft stenosis and a decision of secondary intervention. Retrospective analysis of a contemporary, consecutive series of 353 clinically successful infrainguinal vein bypasses performed in 329 patients for critical (n = 284; 80%) or noncritical (n = 69; 20%) limb ischemia enrolled in a surveillance program to identify and repair duplex-detected graft stenosis. Variables correlated with graft stenosis and bypass repair included: procedure indication, conduit type (saphenous vs nonsaphenous vein; reversed vs nonreversed orientation), prior bypass graft failure, postoperative ankle-brachial index (ABI) < 0.85, and interpretation of the first duplex surveillance study as "normal" or "abnormal" based on peak systolic velocity (PSV) and velocity ratio (Vr) criteria. Overall, 126 (36%) of the 353 infrainguinal bypasses had 174 secondary interventions (endovascular, 100; surgery, 74) based on duplex surveillance; resulting in 3-year Kaplan-Meier primary (46%), assisted-primary (80%), and secondary (81%) patency rates. Characteristics predictive of duplex-detected stenosis leading to intervention (PSV: 443 +/- 94 cm/s; Vr: 8.6 +/- 9) were: "abnormal" initial duplex testing indicating moderate (PSV: 180-300 cm/s, Vr: 2-3.5) stenosis (P < .0001), non-single segment saphenous vein conduit (P < .01), warfarin drug therapy (P < .01), and redo bypass grafting (P < .001). Procedure indication, postoperative ABI level, statin drug therapy, and vein conduit orientation were not predictive of graft revision. The natural history of 141 (40%) bypasses with an abnormal first duplex scan differed from "normal" grafts by more frequent (51% vs 24%, P < .001) and earlier (7 months vs 11 months) graft revision for severe stenosis and a lower 3-year assisted primary patency (68% vs 87%; P < .001). In 52 (15%) limbs, the bypass graft failed and 20 (6%) limbs required amputation. The efficacy of duplex surveillance after infrainguinal vein bypass may be enhanced by modifying testing protocols, eg, rigorous surveillance for "higher risk" bypasses, based on the initial duplex scan results and other characteristics (warfarin therapy, non- single segment saphenous vein conduit, redo bypass) predictive for stenosis development.
    Full-text · Article · Sep 2008 · Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter

  • No preview · Article · Feb 2008 · Journal of Surgical Research
  • Joe P Chauvapun · Paul A Armstrong · Brad L Johnson
    [Show abstract] [Hide abstract]
    ABSTRACT: Carotid duplex ultrasound testing provides a safe and accurate method to detect and grade the severity of atherosclerotic internal carotid artery stenosis both before and following carotid intervention. Testing after surgical endarterectomy or stent angioplasty allows assessment of the technical success by excluding residual stenosis. The focus of duplex surveillance after carotid intervention is to identify recurrent stenosis, repair site occlusion, and progression of contralateral internal carotid artery disease. Patients who develop a neurologic event or a duplex-detected >75% diameter-reducing internal carotid artery stenosis with a peak systolic velocity >300 cm/s and end-diastolic velocity >125 cm/s should be further evaluated by angiographic imaging and should be considered for reintervention if an appropriate lesion is confirmed. Duplex surveillance allows the vascular surgeon to evaluate patency of the rendered intervention, its stenosis-free durability, and its effectiveness in stroke prevention.
    No preview · Article · Jan 2008 · Perspectives in Vascular Surgery and Endovascular Therapy