Intracavernous prostaglandin E1 in erectile dysfunction
Tóm tắt
Prostaglandin E1 (PGE1) is a naturally occurring substance that is present in a variety of mammalian tissues, including the semen of fertile men. Its use in the diagnosis and treatment of erectile dysfunction has been extensively studied. In doses of 10–20 μg, PGE1 produces full erections in 70–80% of patients with erectile dysfunction. In diagnostic use PGE1 is employed as a simple office test and in conjunction with various hemodynamic tests. Self-injection of PGE1, either with the patient or his partner administering the injection, is a minimally invasive and effective treatment for erectile dysfunction in patients with organic or psychogenic erectile dysfunction. Its use is contraindicated in patients with sickle cell anemia, severe coagulopathy, schizophrenia or severe psychiatric disorder, poor manual dexterity, severe venous incompetence, or severe systemic disease. As calculated from data in the published literature, the most frequent side effects are pain at the injection site or during erection (occurring in 16.8% of patients), hematoma/ecchymosis (1.5% of patients), and prolonged erection/priapism (1.3% of patients). The potential for prolonged erection/priapism, the most serious side effect, can be minimized by careful titration of the dose and through patient education. Systemic side effects occur rarely during PGE1 use. During extended use, patients should be monitored for potential long-term side effects, such as fibrosis and angulation.
Tài liệu tham khảo
Aboseif SR, Breza J, Bosch RJLH, Benard F, Stief CG, Stackl W, et al. (1989) Local and systemic effects of chronic intracavernous injection of papaverine, prostaglandin E1, and saline in primates. J Urol (Baltimore) 142:403–408
Adaikan PG, Ng SC, Chan C, Ratnam SS (1990) Why intracavernous PGE1 for diagnosis and treatment of impotence? Int J Impotence Res 2 [Suppl 2]:325–326
Antolin AR, Morales JM, Andres A, Aparicio TF, Gonzales RD, Pamplona M, et al. (1992) Treatment of erectile impotence in renal transplant patients with intracavernosal vasoactive drugs. Transplant Proc 24:105–106
Bellorofonte C, Ruoppolo M, Dell'Acqua S, Zaatar C, Ferri PM, Yamak R, et al. (1991) Intracavernous drug infusion: considerations on studies performed in the past decade and new findings involving PGE1. Archivio Italiano di Urologia 63:475–479 (in Italian)
Bénard F, Lue TF (1990) Self-administration in the pharmacological treatment of impotence. Drugs 39:394–398
Bennett AH, Carpenter AJ, Barada JH (1991) An improved vasoactive drug combination for a pharmacological erection program. J Urol (Baltimore) 146:1564–1565
Beretta G, Zanollo A, Ascani L, Re B (1989) Prostaglandin E1 in the therapy of erectile deficiency. Acta Eur Fertil 20:305–308
Beretta G, Zanollo A, Casella F (1991) New perspectives in the treatment of post-traumatic, neurologic erectile failure. Acta Urologica Italica 3:165–170 (in Italian)
Beretta G, Zanollo A, Portalupi W (1991) Intracavernous injections of prostaglandin E, in the treatment of erectile dysfunctions. Archivio Italiano di Urologica 52:481–485 (in Italian)
Bergström S, Carlson LA, Weeks JR (1968) The prostaglandins: a family of biologically active lipids. Pharmacol Rev 20:1–48
Bookstein JJ(1988) Penile angiography: the last angiographic frontier. AJR Am J Roentgenol 150:47–54
Bosch RJLH, Benard F, Aboseif SR, Stief CG, Stackl W, et al. (1989) Changes in penile hemodynamics after intracavernous injection of prostaglandin E1 and prostaglandin I2 in pigtail monkeys. Int J Impotence Res 1:211–221
Brendler CB, Engel RM, Smoley JK, Allen RP (1991) Objective evaluation of erectile function with intracorporeal papaverine in combination with phentolamine and/or prostaglandin E1 (abstract). J Urol (Baltimore) 145:403A
Broderick G, Lue T (1989) Penile blood flow study and the diagnostic use of prostaglandin E1: a review of 120 patients (abstract). J Urol (Baltimore) 141:288A
Bucher A, Mrstik C, Stoegermayer F (1990) Therapeutic results with PGE1 in the treatment of erectile dysfunction. Aktuelle Urologie 21:17–18
Burgess TR, Earle CM, Glatthaar C, Keogh EJ, Cherry DJ, Lord DJ (1990) Intracavernosal vasoactive agents, comparison of diabetic and non-diabetic impotent men. Int J Impotence Res 2 [Suppl 2]:236–237
Buvat-Herbaut M, Buvat J, Lemaire A, Marcolin G, Dehaene JL (1990) Diagnostic value of intracavernous injection of 20 mg prostaglandin E1 in erectile dysfunction. Int J Impotence Res 2 [Supp1 2]:218–219
Castellani R, Avogadro A, Quadraccia A (1991) Non invasive detection of venogenic impotence: real-time US evaluation of periprostatic (Santorini's) venous plexus after (PGE1) induced erection. Archivio Italiano di Urologica 52 [Suppl. 1]:57–60
Chen J-K, Hwang TIS, Yang C-R (1992) Comparison of effects following intracorporeal injection of papaverine and prostaglandin El. Br J Urol 69:404–407
Chiang H-S, Wen T-C, Wu C-C, Chiang W-H (1990) Prostaglandin E1 versus papaverine for diagnosis of erectile dysfunction. Int J Impotence Res 2 [Suppl 1:127–130
De Domingo Gadea MJ, Sanchez Moreno H, Marin Lafuente JC, Zardoya Mateo MJ, Alonso Rizaldos C, Echeverria Roca M (1991) Evaluation of the efficacy of a prostaglandin E1 solution in the diagnosis of impotence. Farmacia Clinica 8:708–710 (in Italian)
Didolkar AK, Roychowdhury D (1980) Effects of prostaglandins E-1, E-2, F-1a and F-2a on human sperm motility. Andrologia 12:135–140
Earle CM, Keogh EJ, Ker JK, Cherry DJ, Glatthaar C, Tulloch AGS, et al. (1990) Intracavernosal injection therapy for impotence due to spinal cord injury. Int J Impotence Res 2 [Suppl 2]:297–298
Earle CM, Keogh EJ, Wisniewski ZS, Tulloch AGS, Lord DJ, Watters GR, et al. (1990) Prostaglandin E1 therapy for impotence, comparison with papaverine. J Urol (Baltimore) 143:57–59
Earle CM, Keogh EJ, Ker JK, Cherry DJ, Tulloch AGS, Lord DJ (1992) The role of intracavernosal vasoactive agents to overcome impotence due to spinal cord injury. Paraplegia 30:273–276
Floth A, Schramek P (1991) Intracavernous injection of prostaglandin El in combination with papaverine: enhanced effectiveness in comparison with papaverine plus phentolamine and prostaglandin E1 alone. J Urol (Baltimore) 145:56–59
Gerber GS, Levine LA, (1991) Pharmacological erection program using prostaglandin El. J Urol (Baltimore) 146:786–789
Granström E, Samuelsson B (1978) Quantitative measurement of prostaglandins and thromboxanes: general considerations. In: Frölich JC (ed) Advances in prostaglandin and thromboxane research. Raven Press, New York, p 1
Green K, Hamberg M, Samuelsson B, Smigel M, Frölich JC (1978) Measurement of prostaglandins, thromboxanes, prostacyclin and their metabolites by gas liquid chromatography-mass spectrometry. In: Frölich JC (ed) Advances in prostaglandin and thromboxane research. Raven Press, New York, pp 39–94
Hammond GL, Cronau LH, Whittaker D, Gillis CN (1977) Fate of prostaglandins E1 and A1 in the human pulmonary circulation. Surgery 81:716–722
Hanany J, Leibovitch I, Goldwasser B, Chayen D (1990) The hemodynamic effect of intracavernous injection of prostaglandin E1 compared with papaverine-regitine; a Doppler analysis. Int J Impotence Res 2 [Suppl 21:253–254
Hedlund H, Andersson K-E (1985) Contraction and relaxation induced by some prostanoids in isolated human penile erectile tissue and cavernous artery. J Urol (Baltimore) 134:1245–1250
Higgins CB, Braunwald E (1972) The prostaglandins. Biochemical, physiologic and clinical considerations. Am J Med 53:92–112
Hirsch IH, Bagley DH, Christinzio J (1990) Dosage considerations in the self-administration of PGE-1 for erectile dysfunction (abstract). J Urol (Baltimore) 143 [Suppl]:305A
Horton EW (1973) Prostaglandins. In: Gilliland I, Peder M (eds) The scientific basis of medicine annual reviews. Athlone Press, London, pp 58–79
Hwang TI-S, Lue TF, Yang C-R, Chang C-L, Chang C-H, Wu H-S (1989) Comparison of penile vascular effect induced by intracavernous injection of papaverine and prostaglandin E1. J Formosan Med Assoc 88:1038–1041
Hwang TI-S, Yang C-R, Wang S-J, Chang C-L, Tzai TS, Chang C-H (1989) Impotence evaluated by the use of prostaglandin E1. J Urol (Baltimore) 141:1357–1359
Hwang TI-S, Lin M-S, Yang C-R (1990) Dynamic penile washout test. Xe-133 washout study after prostaglandin El intracavernous injection. Int J Impotence Res 2 [Suppl 1]:111–117
Hwang TI, Yang C, Ho WL, Chu H (1991) Histopathological change of corpora cavernosa after long-term intracavernous injection. Eur Urol 20:301–306
Imagawa A, Miyamoto T, Tamura M, Yuasa M (1990) Therapeutic intracavernous injection of a vasoactive drug for mild arterial impotence. Int J Impotence Res 2 [Suppl 1]:131–134
Iribarren IM, Concejo J, Patino GE, Tartajo FV, Cordero JMD, Amo FH, et al. (1992) Duplex echo-Doppler and intracavernous injection of prostaglandin El in the diagnosis of impotence. Arch Esp Urol 45:45–51 (in Spanish)
Ishigooka M, Irisawa C, Watanabe H, Kubota Y, Ishii N (1990) Intracavernous injection of prostaglandin E1: the diagnosis of venogenic impotence. Int J Impotence Res 2 [Supp1 1]:123–125
Ishigooka M, Irisawa C, Watanabe H, Adachi M, Ishii N, Nakada T (1991) Intracavernous injection of prostaglandin E1: the application to cavernosography and penile blood flow measurement for the diagnosis of venogenic impotence. Urol Int 46:193–196
Ishii N, Watanabe H, Irisawa C, Kikuchi Y, Kawamura S, Suzuki K (1986) Studies on male sexual impotence report 18: therapeutic trial with prostaglandin E1 for organic impotence. Nippon Hinyokika Gakkai Zasshi 77:954–962
Ishii N, Watanabe H, Irisawa C, Kikuchi Y, Kubota Y, Kawamura S, et al. (1989) Intracavernous injection of prostaglandin E1 for the treatment of erectile impotence. J Urol (Baltimore) 141:323–325
Mnemann K-P, Alken P (1989) Pharmacotherapy of erectile dysfunction: a review. Int J Impotence Res 1:71–93
Kattan S, Collins JP, Mohr D (1991) Double-blind, crossover study comparing prostaglandin E1 and papaverine in patients with vasculogenic impotence. Urology 37:516–518
Klinge E, Sjostrand NO (1974) Contraction and relaxation of the retractor penis muscle and the penile artery of the bull. A study of effects of drugs and transmural nerve stimulation on isolated smooth muscle strips. Acta Physiol Scand Supp1 420:1–88
Klinge E, Sjostrand NO (1977) Comparative study of some isolated mammalian smooth muscle effectors of penile erection. Acta Physiol Scand 100:354–367
Knispel HH, Andresen R (1992) Color-coded duplex sonography in impotence: significance of different flow parameters in patients and controls. Eur Urol 21:22–26
Krane RJ, Goldstein I, Saenz de Tajada I (1989) Impotence. N Engl J Med 321:1648–1659
Lafuente JCM, Horencia MSM, Echeverria MPF, Ibarguren RL, Pena CP (1990) Intracavernous injection of prostaglandin E1 as a diagnostic test in erectile dysfunction. Arch Esp Urol 43:661–663 (in Spanish)
Lakin MM (1988) Therapeutic pharmacologic erections. In: Doody DJ (ed) Disorders of male sexual function. Year Book Medical Publ, Chicago, pp 223–229
Lee LM, Stevenson RWD, Szasz G (1989) Prostaglandin El versus phentolamine/papaverine for the treatment of erectile impotence: a double-blind comparison. J Urol (Baltimore) 141:549–550
Liu L-C, Wu C-C, Liu L-H, Chiang C-P, Huang CH, Chou Y-H (1991) Comparison of the effects of papaverine versus prostaglandin El on penile blood flow by color duplex sonography. Eur Urol 19:49–53
Lue TF (1992) Pilot study with alprostadil (prostaglandin E1, PGE1, PROSTIN VR Pediatric sterile solution) in patient with erectile dysfunction. (unpublished)
Lui SM-C, Lin JS-N (1990) Treatment of impotence: comparison between the efficacy and safety of intracavernous injection of papaverine plus phentolamine (regitine) and prostaglandin E1. Int J Impotence Res 2 [Suppl 1]:147–157
Mahmoud KZ, El Dakhli MR, Fahmi IM, Abdel-Azia ABA (1992) Comparative value of prostaglandin El and papaverine in treatment of erectile failure: double-blind crossover study among Egyptian patients. J Urol (Baltimore) 147:623–626
Mattarelli G, Leibundgut B (1990) Prostaglandin-E1 oneway syringes for routine diagnostic of erectile dysfunction. Int J Impotence Res 2 [Suppl 21:220–221
Mattarelli G, Leibundgut B (1991) Preliminary experience with prostaglandin E1 and PGE1 ready-to-use injections. Helv Chir Acta 58:335–337
Merckx L, Vanwaeyenbergh J, De Bruyne R, Braeckman J, Keuppens F (1991) The use of prostaglandines for diagnosis and treatment of erectile impotence. Acta Urologica Belgica 59:47–52
Meuleman EJH, Bemelmans BLH, Doesburg WH, van Asten WNJC, Skotnicki SH, Debruyne FMJ (1992) Penile pharmacological duplex ultrasonography: a dose-effect study comparing papaverine, papaverine/phentolamine and prostaglandin E1. J Urol (Baltimore) 148:63–66
Mori K, Nakajima H, Onishi S, Kato S, Tanda H, Horita K, et al. (1988) A study on impotence: treatment of impotence with prostaglandin E1 (abstract). Nippon Hinyokika Gakkai Zasshi 79:1886–1887
Nseyo UO, Wilbur HJ, Kang SA, Flesh I, Bennett AH (1984) Penile xenon (Xe-133) washout: a rapid method of screening for vasculogenic impotence. Urology 23:31–34
Oblak C, Ravnik Oblak M (1990) Intracavernous injection of prostaglandin E1 in impotent diabetic men. Int J Impotence Res 2 [Suppl 2]:263–264
Padma-Nathan H (1990) The efficacy and synergy of polypharmacotherapy in primary and salvage therapy of vasculogenic erectile dysfunction. Int J Impotence Res 2 [Suppl 2]:257–258
Padma-Nathan H, Payton T, Goldstein I (1987) Treatment of organic impotence: alternatives to the penile prosthesis. American Urological Association, Houston
Pagano F, Calabro A, Ostardo E, Cisternino A, Maio G, Aragona F, et al. (1990) Prostaglandin E1: prostaglandin E1 in the study of erectile impotence. Bas Raz Ter 20:387–390 (in Spanish)
Piper PJ (1973) Distribution and metabolism. In: Cuthbert MF (ed) The prostaglandins. Heinemann, London, pp 125–150
Porst H (1988) Die erektile Dysfunktion. Praxis-orientierte Diagnostik der erektilen Dysfunktion (ED) und therapeutische Konsequenzen. Z Allgemeinmedizin 64:325–333
Porst H (1988) Comparative usefulness of prostaglandin E1, papaverine and papaverine/phentolamine for the diagnosis of erectile dysfunction in 61 patients. Urologe A 27:22–26
Porst H (1989) Prostaglandin E1 in erectile dysfunction. Urologe A 28:94–98
Porst H (1992) Prostaglandin E1 in male impotence — its diagnostic and therapeutic use in 2000 patients (abstract). Int J Impotence Res 4 [Suppl 2]:A88
Porst H, Ebeling L (1989) Erektile Dysfunktion. Übersicht und aktueller Stand von Diagnostik und Therapie. Fortschr Med 107:44–53
Porst H, VanAhlen H, Block TH, Halbig W, Hautmann R, Lochner-Ernst D, et al. (1989) Intracavernous self-injection of prostaglandin E1 in the therapy of erectile dysfunction. Vasa Suppl 28:50–56
Porst H, VanAhlen H, Block T, Halbig W, Hautmann R, Lochner-Ernst D, et al. (1990) Intracavernous self-injection therapy with prostaglandin E1 — results of a multicenter study with 189 patients. Int J Impotence Res 2 [Suppl 2]:259–260
Puppo P, DeRose AF, Pittaluga P (1989) Erection induced by PGE1. A preliminary study. Presented at the VI Congresso Nazionale Societa Italiana di Andrologia, Florence, 13 May (in Italian) 78. Quadraccia A, Castellani R, Salvini A, Baresi A (1989) Use of prostaglandin El in erection disorders. Presented at the VI Congresso Nazionale Societa Italiana di Andrologia, Florence, 13 May (in Italian)
Raboy A, Combs A, Godec CJ, Irwin M, Grunberger I (1990) Comparison of papaverine and prostaglandin E1 (PGE1) in impotent pts (abstract). J Urol (Baltimore) 143 [Suppl]:303A
Rauchenwald M, Petritsch PH, Stenzl A (1990) Our experience with the prostaglandin E1 intracavernous self-injection test (ICSI). A new form of administration of ICSI (abstract). Proceedings from the 11th International Symposium Vienna, 22–24 February 1990, p 55 (in German)
Ravnik-Oblak M, Oblak C, Vodusek DB, Kristl V, Ziherl S (1990) Intracavernous injection of prostaglandin E1 in impotent diabetic men. Int J Impotence Res 2:143–150
Reiss H (1989) Use of prostaglandin E1 for papaverinefailed erections. Urology 33:15–16
Rosenkranz B, Fischer C, Boeynaems J-M, Frölich JC (1983) Metabolic disposition of prostaglandin E1 in man. Biochim Biophys Acta 750:231–236
Roy JB, Petrone RL, Ibrahin T (1990) A clinical trial of the intracorporal injection of papaverine/phentolamine vs PGE1 vs topical nitroglycerin ointment in the treatment of erectile dysfunction. Int J Impotence Res 2 [Suppl 2]:305–306
Sarosdy MF, Hudnall CH, Erickson DR, Hardin TC, Novicki DE (1989) A prospective double-blind trial of intracorporeal papaverine versus prostaglandin E1 in the treatment of impotence. J Urol (Baltimore) 141:551–553
Schramek P, Waldhauser M (1989) Dose-dependent effect and side-effect of prostaglandin E1 in erectile dysfunction. Br J Clin Pharmacol 28:567–571
Schramek P, Dorninger R, Waldhauser M, Konecny P, Porpaczy P (1990) Prostaglandin E1 in erectile dysfunction: efficiency and incidence of priapism. Br J Urol 65:68–71
Shirai M, Nakamura M (1970) Differential diagnosis of organic and functional impotence by the use of 131-iodine labelled human serum albumin. Tohuku J Exp Med 101:317–324
Sidi AA (1988) Vasoactive intracavernous pharmacotherapy. Urol Clin North Am 15:95–101
Siraj QH, Akhtar MA (1989) Intracavernosal injection of pharmacological agents in the diagnosis and treatment of impotence. J Postgrad Med 39:172–176
Siraj QH, Bomanji J, Akhtar MA, Rana MH, Sadiq M, Ahmed M (1990) Quantitation of pharmacologically-induced penile erections: the value of radionuclide phallography in the objective evaluation of erectile haemodynamics. Nuclear Med Commun 11:445–458
Sister MP (1990) Prostaglandin El in erectile dysfunction: 20 months of experience with 483 patients in a self-injection program. Int J Impotence Res 2 [Suppl 2]:287–288
Soli M, Brunocilla E, D'Amato G, Scarano P, Steccanella S, Raitano A, et al. (1991) Intracavernous prostaglandin E1 (PGE1) in the diagnosis and treatment of erectile dysfunction. Acta Urologica Italica 3:227–229
Stackl W, Hasun R, Marberger M (1988) Intracavernous injection of prostaglandin El in impotent men. J Urol (Baltimore) 140:66–68
Stackl W, Loupal G, Holzmann A (1988) Intracavernous injection of vasoactive drugs in the rabbit. Urol Res 16:455–458
Stackl W, Hasun R (1990) Prostaglandin E1 — 4 years experience of intracavernous injection. Int J Impotence Res 2 [Suppl 2]:255–256
Stackl W, Hasun R (1990) Treatment of impotence with prostaglandin E1 after surgery in the minor pelvis (abstract). Proceedings of the 11th International Symposium, Vienna, 22–24 February 1990, p 56 (in German)
Stackl W, Hasun R, Marberger M (1990) The use of prostaglandin E1 for diagnosis and treatment of erectile dysfunction. World J Urol 8:84–86
Stief CG, Wetterauer U, Schaebsdau FH, Jonas U (1991) Calcitonin-gene-related peptide: a possible role in penile erection and its therapeutic application in impotent patients. J Urol (Baltimore) 146:1010–1014
Tamura M, Hashine K, Kimura K, Kawanishi Y, Imagawa A (1990) Comparison of the effect of papaverine hydrochloride and prostaglandin E1 on human corpus cavernosum. Int J Impotence Res 2 [Suppl 1]:141–145
Templeton AA, Cooper I, Kelly RW (1978) Prostaglandin concentrations in the semen of fertile men. J Reprod Fertil 52:147–150
Tulli RE, Di Iorio J, Garcia JA, Barbato CR, Degni M (1990) Self-injection with several vasoactive drugs. Int J Impotence Res 2 [Suppl 2]:283–284
Vaccari R, Pezzoni F, Treffiletti S, Scuzzarella S, Zucca R (1990) The use of PGEl in arterial rehabilitation in patients affected from cavernous “venous leakage” disease after operations of crural cavernousplastic and binding of the deep dor vein and crural veins. Int J Impotence Res 2 [Suppl 2]:232–233
Van Ahlen H, Peskar BA, Sticht G (1990) Pharmacokinetics of vasoactive substances following injection into the cavernous body (abstract). Proceedings from the 11th International Symposium, Vienna, 22–24 February 1990, p 37 (in German)
Virag R (1982) Intracavernous injection of papaverine for erectile failure. Lancet 11:938
Virag R, Adaikan PG (1987) Effects of prostaglandin E1 on penile erection and erectile failure (letter). J Urol (Baltimore) 137:1010
Waldhauser M, Schramek P (1988) Efficiency and side effects of prostaglandin E1 in the treatment of erectile dysfunction. J Urol (Baltimore) 140:525–527
Watanabe H (1990) Hemodynamic study on erection induced by intracavernous injection of prostaglandin E1. Nihinyo-Kaishi 81:732–738 (in Japanese)
Weeks JR (1972) Prostaglandins. Annu Rev Pharmacol Toxicol 12:317–336
Wein AJ, Malloy TR, Hanno PM (1987) Intracavernosal injection programs. Probl Urol 1:496–506
Weiske W-H (1989) Three years' experience with intracavernous self-injection therapy. Urologe A 28:253–257
Weiske W-H (1990) Prostaglandin E1 (PGE1) in diagnosis and treatment of erectile dysfunction (ED). Int J Impotence Res 2 [Suppl 2]:234–235
Weiske W-H (1992) Long-term results in self-injection therapy (SIT) with PGE1 in 220 patients. Int J Impotence Res 4 [Suppl 2]:A87
Wetterauer U, Koppermann U, Bischoff R, Sommerkamp H (1990) Intraindividual comparison of papaverine-phentolamine combination versus prostaglandin E1 in intraca vernous injection therapy for erectile dysfunction. Int J Impotence Res 2 [Suppl 2]:238–239
Whitehead ED, Klyde BJ, Zussman S, Salkin P (1990) Diagnostic evaluation of impotence. Postgrad Med 88:123–136
Wilms G, Peene P, Steeno O, Baert AL (1992) Intracavernosal injection of prostaglandin E1 as an alternative for papaverine in penile angiography. Urol Radiol 14:59–61
Yasumoto R, Asakawa M (1988) Intracavernous injection of vasoactive drugs for treating erectile impotence (abstract). Hinyokika Kiyo. Acta Urologica Japonica (Kyoto) 34:301–304 (in Japanese)
Yeh SH, Liu RS, Chen KK, Wu LC, Ng MN, Chu YK, et al. (1992) Diagnosis of venous leakage by 133Xe corporeal clearance after intracavernous injection of prostaglandin E1 in poorly responding patients. Nuclear Med Commun 13:28–32