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Eval/Workup

History

• HPI: onset, severity/rigidity, degree of bother, situational factors, pain, stable/worsening symptoms
• Age: prevalence 1-10% < 40yo, 15% 40-49yo, 30% 50-59yo, 40% 60-69yo, 50-100% 70-90yo
• Commonly associated risk factors: HTN (38-42%), DM (20%), HLD (42%), depression (11%), premature ejaculation (30-60%)
• PMHx: cardiovascular disease, DM, endocrine issues (hypoT), neurologic disorders, psych diagnoses (depression, anxiety, stress), liver disease, alcoholism
• PSHx: prostatectomy, cystectomy, aortoiliac vascualr surgery, aneurysm repair, proctocolectomy, pituitary surgery, penile surgery, pelvic trauma
• Meds: antiHTN, SSRIs, TCAs, antipsychotics, MAOi, antiandrogens, cimetidine, opiates, 5ARi, LHRH agonists/antagonists, prior ED therapies
• Social Hx: partner(s), substance use
• Psychosexual factors: social, cultural, religious, education

Key Questions

1. Are you able to obtain + sustain an erection satisfactory for intercourse?
2. Do you have morning and/or nocturnal erections?
3. Are you able to masturbate?

Physical

• Vitals: check for uncontrolled HTN
• Testosterone deficiency: obesity, gynecomastia, decreased body hair
• Genital exam: hypogonadism, penile curvature, testis presence and size
• DRE: not required for evaluation

Further Diagnostics

• Questionnaires: IIEF or SHIM (abridged version of IIEF)
• Labs: can check BMP, glucose, lipids, HbA1c, testosterone (draw in AM)
• Low testosterone: check bioavailable (serum-free) T (albumin + SHBG) and luteinizing hormone, consider prolactin and estrogen
• Further workup (see below): consider if young, family hx cardiac disease, pelvic trauma, failed prior therapy, likely psychogenic, Peyronie disease, lifelong ED

Adjunct testing

• Almost never required prior to offering treatment options, as only patients with arterial insufficiency benefit from specific treatment options
• Nocturnal penile tumescence/rigidity (NPTR): detects erections during REM w/ strain gauge, BP cuff, "stamp roll test," determines organic vs psychogenic ED
• ICI + stimulation: good erection after 10min rules out veno-occlusive disease but not arterial insufficiency
• Penile duplex doppler sonography: perform ICI then examine, check arterial and venous flow
• Cavernosometry: place two needles in corpora, infuse heparinized saline and inject erectogenic medication, measure intracavernosal pressure, assess "flow to maintain" (flow required to maintain pressure 150mmHg) and "intracavernosal pressure decay (pressure decline after stopping infusion)
• Cavernosography: infuse contrast during cavernosometry and obtain images
• Pudendal arteriography: gold standard for assessing arterial insufficiency, assess patency of inferior epigastrics, stenosis of penile blood supply, ability to bypass blockages
• Cavernous arterial systolic occulsion pressure (CASOP): perform ICI, then use BP cuff to determine presure when blood flow becomes detectable
• Penile brachial index: similar to CASOP but measured when flaccid, penile SBP divided by brachial SBP

Test	Arterial insufficiency	Venous leak	Psychogenic ED
NPTR	Poor erection		Good erection
ICI + stimulation
Penile ultrasound	PSV < 30cm/s PSV < 60cm/s (sum of R + L) cavernous artery diameter < 0.7mm	Normal PSV, EDV < 3cm/s RI ≤ 0.8	No abnormalities
Cavernosometry	No abnormalities	Flow to maintain < 3mL/min IC pressure decay > 45mmHg in 30s
Cavernosography		Venous drainage visualized
CASOP	Brachial SBP - CASOP < 35mmHg	No abnormalities
Penile brachial index	PBI ≤ 0.7

Cardiac evaluation

Importance of evaluation

• Penis/heart relationship: the penis is the dipstick of the heart, development of ED can predate cardiac disease by 5-10 years (25% increased risk at 10yrs)
• MI risk during intercourse: sex causes < 1% MI, absolute risk < 0.01% within 2hr sex
• Assess METS: ask whether patient tolerate 20min walking on flat surface or walking 2 flights stairs in 10 seconds, if patient can tolerate 3 METs activity without chest pain then can tolerate sexual activity
• Workup: check blood pressure, T, lipids, HbA1c if not checked within past 12mo
• Cardiac meds: PDE5i contraindicated if taking nitrates, guanylate cyclase stimulators (riociguat, nicorandil), vardenafil contraindicated with QT prolonging antiarrhymthics, a-blockers + PDE5i can worsen hypotension

Princeton III criteria

• Low risk: no cardiac disease and able to exercise w/o symptoms, have undergone successful revascularization, Class I-II heart failure, controlled asymptomatic HTN, mild cardiac valve disease
• Intermediate risk: mild/moderate stable angina, MI in past 2-8 weeks, Class III heart failure, or non-cardiac vascular disease (PVD, CVA, TIA)
• High risk: unstable/refractory angina, recent MI (< 2 weeks), arrythmias, uncontrolled HTN/DM, Class IV heart failure, moderate/severe valve disease, obstructive hypertrophic cardiomyopathy
• Management: intermediate/high risk require cardiology consult/evaluation prior to starting ED therapies, low risk requires no further workup

PDE5 Inhibitors

Tips for Improved Efficacy

• Use 9-10 times before increasing dose
• Increased dose increases side effects but not efficacy
• Sexual stimulation required
• No evidence that early use helps regain erections after prostatectomy
• Overall 70% report success with sexual intercourse, only 40-50% if diabetic

Risks/Contraindications

• Contraindications: nitrates, severe liver/renal disease
• Relative contraindications: baseline hypotension or hypertension, drugs that increase PDE5i halflife (Cyp-P450 3A4 inhibitors), retinitis pigmentosa, cardiovascular disease
• a-blockers + PDE5i: okay to use but increased risk for hypotension
• nitrates + PDE5i: no pharmacologic antidote if co-administered
• Hypotension management: fluids, a-agonists, Trendelenburg position, rarely requires intraaortic balloon pump
• Cross-reactions: antidepressants, antifungals, antiHTN, HAART
• Common side effects: dyspepsia (4-10%), headache (7-16%), flushing (4-10%), myalgia + back pain (0-3%, congestion (3-4%), visual disturbances (0-3%)
• Blue/green color vision change: due to PDE6 cross-reactivity, not seen with tadalafil
• Sudden unilateral vision loss (NAION): overall extremely rare (3/100K), possibly not even a real association

Options

Drug	Dosing	Onset	Avoid with fatty food	Headache/Dyspepsia/Flushing	Backache/Myalgias	Blurred/Blue Vision
Sildenafil (Viagra)	25-100mg	30-60min	Yes	Yes	Rare	Yes
Tadalafil (Cialis)	5-20mg	60-120min	No	Yes	Yes	Rare
Vardenafil (Levitra)	5-20mg	30-60min	Yes	Yes	Rare	Rare

Everything but PDE5i and IPP

Lifestyle changes

• General tips: maintain ideal weight, exercise
• Drug use: stop smoking, alcohol, and other drug use
• Medications: stop or switch to medications with lower ED risk
• Comorbidities: optimize HTN, DM, cardiac disease
• Psychogenic ED: consider sexual counseling

Intracavernosal Injections

• Options: alprostadil (cAMP stimulator), papaverine (non-specific PDEi), phentolamine (a1-blocker), atropine, bimix (papaverine + phentolamine), trimix (bimix + alprostadil)
• Efficacy: 54-100%, satisfaction 46-99%
• Side effects: priapism (highest with papaverine), pain (highest with alprostadil), fibrosis (highest with papaverine), hypotension and systemic side effects (highest with veno-occlusive leak)
• Contraindications: hx pripaism, coagulopathy, unstable cardiac disease, reduced manual dexterity, MAOi use (HTN crisis if a-agonist needed to reverse a priapism)
• Anticoagulation: not a contraindication, hold pressure to prevent hematoma
• Dosing: alprostadil (2.5-60ug/mL), bimix (20ug/mL + 0.5mg/mL), trimix (10ug/mL + 30mg/mL + 1mg/mL), maximum 3x weekly with > 24hr between doses

Vacuum Assist Device + Occlusion ring

• Satisfaction: patient (60-80%), partner (70+%)
• Weak seal: trim pubic hair and use adequate lubricant
• Abnormal sensation: may create fulcrum effect (flaccid proximal, rigid distal) or abnormal feel/appearance (blue/gray color, cool to touch)
• Side effects: bruising (18%), pain (18%), difficult ejaculation (22%), device difficulty (20%)
• Contraindications: priapism risk, penile fibrosis, bleeding disorder or anticoagulation (can cause hematoma)
• Frequency: do not use for > 30min, wait at least 1hr between uses

Intraurethral Alprostadil (MUSE)

• Dosing: 125, 250, 500, 1000 mcg
• Directions: urinate before use, insert pill/applicator, roll penis to dissolve medication, use maximum BID, test in office prior to prescribing (2% risk hypotension)
• Efficacy: 50-70%
• Side effects: genital pain (6.5-35%), urethral trauma (1-5%), urethral pain (0-29%), dizziness (0-7%), painful erection (1%), potential risk for priapism
• Contraindications: high risk for priapism, distal urethral stricture, penile fibrosis, balanitis, urethritis, having sex with pregnant woman (unless using condom)

Testosterone therapy (see separate page)

• Do not supplement testosterone if normal T levels
• Baseline assessment: DRE, PSA, CBC, LFT, lipids, repeat 3-6mo after starting treatment, then annually
• Give short course testosterone (3mo), if no improvement then discontinue
• Common side effects: increased Hgb, OSA, gynecomastia, acne

Arterial revascularization

• Indications: only patients with proven arterial insufficiency, usually focal stenosis from trauma
• Contraindications: atherosclerosis, veno-occlusive disease, tobacco use
• Procedure: anastomose inferior epigastric to dorsal penile artery or deep dorsal penile vein, can cause glans hyperemia, success rates 60-70% at 5yr

Penile Prosthesis

Counseling

• Irreversible treatment (destroys native corpora)
• Can use with VED, does not work with other ED treatments
• Satisfaction: 86-98% (inflatable), 66-89% (malleable)
• Expectations: will not replicate normal appearing erections, lengthen penis, engorge glans, affect libido, dissatisfaction reported due to perceived length, chronic pain/coolness, difficulty operating, decreased sensation
• Malleable implant: can be used to keep condom catheter in place (spinal cord injury), but increased risk for erosion if poor/no sensation
• Predictors of postop dissatisfaction (CURSED Penis): Compulsive, Unrealistic, Revision, Surgeon shopping, Entitled, Denial, and Psychiatric
• Preoperative optimization: ensure no UTI or systemic infection, HbA1c < 7.5-8.5%

Risks + Side Effects

• Post-surgical side effects: penile edema/hematoma (3%), urinary retention (2%)
• Urethral injury: 1-3% risk, abort procedure, repair urethra, place catheter, consider placement in 4-6 weeks, can leave cylinder in uninjured side (if already dilated) to avoid shortening
• Crural injury: 1-3% risk, do not need to abort procedure but does require repair to prevent proximal sliding
• Crossover: ensure correct location during dilation, can fix intraop without aborting procedure, may present postoperatively and require repair to resituate
• Infection: 2-5% risk, usually within 3mo implantation, requires immediate explant of all implanted parts, can occasionally attempt salvage replacement,
• Erosion: 2% risk, more common in SCI (unable to feel erosion occurring), surgery to remove and repair overlying tissue with placement of spacer cylinder, can replace after 5-6mo
• Extrusion: surgery to resituate cylinder in correct position vs repair + explant
• Failure: 5-40% risk at 10-15yrs
• Reservoir erosion into bowel/bladder: rare, requires device removal and repair
• Penile necrosis: rare, can be caused by compromising distal blood flow in high-risk patients, remove device to optimize blood flow
• Aneurysm: cylinder herniation through corporotomy defect (early) or weakness of device wall due to frequent/aggressive long-term use, identify with physical exam or MRI, replace cylinders
• Penile shortening: no objective difference noted, some subjective differences reported
• Cold glans: due to lack of engorgement, can use PDE5i or MUSE to help engorge glans tissue
• Glans bowing (concorde deformity): cylinders too short, replace with longer cylinders or anchor glans to distal corpora tunica albuginea through dorsal subcoronal incision
• Glans buckling (S-shaped deformity): cylinders too long, requires replacing with adequate length cylinders
• Autoinflation: occurs with increased abdominal pressure on reservoir, more common if no lockout valve, prevent with low pressure cavity for reservoir, can replace reservoir