Background: Different surgical techniques have been indicated for the management of Zenker's diverticulum (ZD), including diverticulectomy, diverticulopexy, and diverticular inversion, with or without myotomy, and myotomy alone. More recently, minimally invasive techniques (such as the transoral endoscopic approach) have become increasingly reliable for this disorder. We therefore conducted this systematic review in order to gain a profound understanding of the current trend and evidence in surgical management of ZD. Methods: Medline and PubMed were searched to identify studies on surgical intervention of ZD published in English between January 1990 and March 2011. Results: We identified 6,915 patients from 93 studies evaluating the effect of the surgical intervention for ZD. No randomized controlled trials comparing one technique with another were identified. Conclusion: Diverticulectomy with myotomy has become the mainstream treatment option for ZD. In certain selected patients, endoscopic diverticulotomy may offer some advantages over open surgery, such as less trauma and a lower complication rate. It is important to individualize optimal therapy for each patient. More randomized controlled trials with long-term follow-up results are required to draw a valid conclusion on the best surgical intervention modality for ZD.

Keywords:
Zenker’s diverticulum, Surgery, Treatment
1.
Ludlow A: A case of obstructed deglutition, from a preternatural dilatation of, and bag formed in, the pharynx. Med Obs Inq 1767;3:85.
2.
Zenker F, von Ziemssen H: Krankheiten des Oesophagus. Leipzig, F.C. Vogel, 1877, vol 7, pp 1-87.
3.
Yeo JC, Mackenzie K: Pharyngeal pouch surgery in north Glasgow: NICE (National Institute for Health and Clinical Excellence) practice or not? J Laryngol Otol 2010;124:533-537.
4.
Cook IJ, Blumbergs P, Cash K, Jamieson GG, Shearman DJ: Structural abnormalities of the cricopharyngeus muscle in patients with pharyngeal (Zenker's) diverticulum. J Gastroenterol Hepatol 1992;7:556-562.
5.
Hillel AT, Flint PW: Evolution of endoscopic surgical therapy for Zenker's diverticulum. Laryngoscope 2009;119:39-44.
6.
Wheeler WI: Pharyngocoele and dilation of the pharynx, with existing diverticulum at lower portion of pharynx lying posterior to the oesophagus, cured by pharyngotomy, being the first of the kind recorded. Dublin J Med Sci 1886;82:349-356.
7.
Mosher H: Webs and pouches of the oesophagus, their diagnosis and treatment. Surg Gynecol Obstet 1917;25:175.
8.
Peretti G, Piazza C, Del Bon F, Cocco D, De Benedetto L, Mangili S: Endoscopic treatment of Zenker's diverticulum by carbon dioxide laser. Acta Otorhinolaryngol Ital 2010;30:1-4.
9.
Case DJ, Baron TH: Flexible endoscopic management of Zenker diverticulum: the Mayo Clinic experience. Mayo Clin Proc 2010;85:719-722.
10.
Costamagna G, Iacopini F, Tringali A: Flexible endoscopic Zenker's diverticulotomy: cap-assisted technique vs. diverticuloscope-assisted technique. Endoscopy 2007;39:146-152.
11.
Christiaens P, De Roock W, Van Olmen A, Moons V, D'Haens G: Treatment of Zenker's diverticulum through a flexible endoscope with a transparent oblique - end hood attached to the tip and a monopolar forceps. Endoscopy 2007;39:137-140.
12.
Miller FR, Bartley J, Otto RA: The endoscopic management of Zenker diverticulum: CO2 laser versus endoscopic stapling. Laryngoscope 2006;116:1608-1611.
13.
Rabenstein T, May A, Michel J: Argon plasma coagulation for flexible endoscopic Zenker's diverticulotomy. Endoscopy 2007;39:141-145.
14.
Vogelsang A, Preiss C, Neuhaus H, Schumacher B: Endotherapy of Zenker's diverticulum using the needle-knife technique: long-term follow-up. Endoscopy 2007:39:131-136.
15.
Chang CY, Payyapilli RJ, Scher RL: Endoscopic staple diverticulostomy for Zenker's diverticulum: review of literature and experience in 159 consecutive cases. Laryngoscope 2003;113:957-965.
16.
Mattinger C, Hormann K: Endoscopic diverticulotomy of Zenker's diverticulum: management and complications. Dysphagia 2002;17:34-39.
17.
Repici A, Pagano N, Fumagalli U, Peracchia A, Narne S, Malesci A, Rosati R: Transoral treatment of Zenker diverticulum: flexible endoscopy versus endoscopic stapling. A retrospective comparison of outcomes. Dis Esophagus 2011;24:235-239.
18.
Counter P, Hilton M, Baldwin DL: Long-term follow-up of endoscopic stapled diverticulotomy. Ann R Coll Surg Engl 2002;84:89-92.
19.
Jaramillo MJ, McLay KA, McAteer D: Long-term clinicoradiological assessment of endoscopic stapling of pharyngeal pouch: a series of cases. J Laryngol Otol 2001;115:462-466.
20.
Thaler ER, Weber RS, Goldberg AN, Weinstein GS: Feasibility and outcome of endoscopic staple-assisted esophagodiverticulostomy for Zenker's diverticulum. Laryngoscope 2001;111:1506-1508.
21.
Adams J, Sheppard B, Andersen P: Zenker's diverticulostomy with cricopharyngeal myotomy: the endoscopic approach. Surg Endosc 2001;15:34-37.
22.
Cook RD, Huang PC, Richtsmeri WJ, Scher RL: Endoscopic staple-assisted esophagodiverticulostomy: an excellent treatment of choice for Zenker's diverticulum. Laryngoscope 2000;110:2020-2025.
23.
Omote K, Feussner H, Stein HJ, Ungeheuer A, Siewert JR: Endoscopic stapling diverticulostomy for Zenker's diverticulum. Surg Endosc 1999;13:535-538.
24.
Mulder CJ: Zapping Zenker's diverticulum: gastroscopic treatment. Can J Gastroenterol 1999;13:405-407.
25.
Peracchia A, Bonavina L, Narne S: Minimally invasive surgery for Zenker's diverticulum: analysis of results in 95 consecutive patients. Arch Surg 1998;133:695-700.
26.
Baldwin DL, Toma AG: Endoscopic stapled diverticulotomy: a real advance in the treatment of hypopharyngeal diverticulum. Clin Otolaryngol Allied Sci 1998;23:244-247.
27.
Wasserzug O, Zikk D, Raziel A, Cavel O, Fleece D, Szold A: Endoscopically stapled diverticulostomy for Zenker's diverticulum: results of a multidisciplinary team approach. Surg Endosc 2010;24:637-641.
28.
Repici A, Pagano N, Romeo F, Danese S, Arosio M, Rando G, Strangio G, Carlino A, Malesci A: Endoscopic flexible treatment of Zenker's diverticulum: a modification of the needle-knife technique. Endoscopy 2010;42:532-535.
29.
Khetani JD, Janjua A, Fenton RS: Staple-assisted endoscopic management of Zenker's diverticula: a role in the geriatric population. Indian J Otolaryngol Head Neck Surg 2009;61:200-204.
30.
Gross ND, Cohen JI, Andersen PE: Outpatient endoscopic Zenker diverticulotomy. Laryngoscope 2004;114:208-211.
31.
Sharp DB, Newman JR, Magnuson JS: Endoscopic management of Zenker's diverticulum: stapler-assisted versus Harmonic Ace. Laryngoscope 2009;119:1906-1912.
32.
Palmer AD, Herrington HC, Rad IC, Cohen JI: Dysphagia after endoscopic repair of Zenker's diverticulum. Laryngoscope 2007;117:617-622.
33.
Chiari C, Yeganehfar W, Scharitzer M, Mittlböck M, Armbruster C, Roka R, Függer R, Wenzl E, Pokieser P, Bischof G: Significant symptomatic relief after transoral endoscopic staple-assisted treatment of Zenker's diverticulum. Surg Endosc 2003;17:596-600.
34.
Fama AF, Moore EJ, Kasperbauer JL: Harmonic scalpel in the treatment of Zenker's diverticulum. Laryngoscope 2009;119:1265-1269.
35.
Hashiba K, de Paula AL, da Silva JG, Cappellanes CA, Moribe D, Castillo CF, Brasil HA: Endoscopic treatment of Zenker's diverticulum. Gastrointest Endosc 1999;49:93-97.
36.
Narne S, Cutrone C, Bonavina L, Chella B, Peracchia A: Endoscopic diverticulotomy for the treatment of Zenker's diverticulum: results in 102 patients with staple-assisted endoscopy. Ann Otol Rhinol Laryngol 1999;108:810-815.
37.
Lippert BM, Folz BJ, Rudert HH, Werner JA: Management of Zenker's diverticulum and postlaryngectomy pseudodiverticulum with the CO2 laser. Otolaryngol Head Neck Surg 1999;121:809-814.
38.
Sood S, Newbegin CJ: Endoscopic stapling of pharyngeal pouches in patients from the Yorkshire region. J Laryngol Otol 2000;114:853-857.
39.
Nyrop M, Svendstrup F, Jorgensen KE: Endoscopic CO2 laser therapy of Zenker's diverticulum: experience from 61 patients. Acta Otolaryngol Suppl 2000;543:232-234.
40.
Luscher MS, Johansen LV: Zenker's diverticulum treated by the endoscopic stapling technique. Acta Otolaryngol Suppl 2000;543:235-238.
41.
Krespi Y, Kacker A, Remacle M: Endoscopic treatment of Zenker's diverticulum using CO2 laser. Otolaryngol Head Neck Surg 2002;127:309-314.
42.
Evrard S, Le Moine O, Hassid S, Deviere J: Zenker's diverticulum: a new endoscopic treatment with a soft diverticuloscope. Gastrointest Endosc 2003;58:116-120.
43.
Visosky AM, Parke RB, Donovan DT: Endoscopic management of Zenker's diverticulum: factors predictive of success or failure. Ann Otol Rhinol Laryngol 2008;117:531-537.
44.
Aly A, Devitt PG, Watson DI, Jamieson GG, Bessell JR, Chew A, Krishnan S: Endoscopic stapling for pharyngeal pouch: does it make the cut? ANZ J Surg 2004;74:116-121.
45.
Roth JA, Sigston E, Vallance N: Endoscopic stapling of pharyngeal pouch: a 10-year review of single versus multiple staple rows. Otolaryngol Head Neck Surg 2009;140:245-249.
46.
Ozgursoy OB, Salassa JR: Functional and manofluorographic outcomes after transoral endoscopic pharyngoesophageal diverticulostomy. Arch Otolaryngol Head Neck Surg 2010;136:463-467.
47.
Helmstaedter V, Engel A, Huttenbrink KB, Guntinas-Lichius O: Carbon dioxide laser endoscopic diverticulotomy for Zenker's diverticulum: results and complications in a consecutive series of 40 patients. ORL J Otorhinolaryngol Relat Spec 2009;71:40-44.
48.
Kos MP, David EF, Mahieu HF: Endoscopic carbon dioxide laser Zenker's diverticulotomy revisited. Ann Otol Rhinol Laryngol 2009;118:512-518.
49.
Stoeckli SJ, Schmid S: Endoscopic stapler-assisted diverticuloesophagostomy for Zenker's diverticulum: patient satisfaction and subjective relief of symptoms. Surgery 2002;131:158-162.
50.
Hoffmann M, Scheunemann D, Rudert HH, Maune S: Zenker's diverticulotomy with the carbon dioxide laser: perioperative management and long-term results. Ann Otol Rhinol Laryngol 2003;112:202-205.
51.
Raut VV, Primrose WJ: Long-term results of endoscopic stapling diverticulotomy for pharyngeal pouches. Otolaryngol Head Neck Surg 2002;127:225-229.
52.
Bloom JD, Bleier BS, Mirza N, Chalian AA, Thaler ER: Factors predicting endoscopic exposure of Zenker's diverticulum. Ann Otol Rhinol Laryngol 2010;119:736-741.
53.
Mulder CJ, den Hartog G, Robijn RJ, Thies JE: Flexible endoscopic treatment of Zenker's diverticulum: a new approach. Endoscopy 1995;27:438-442.
54.
Ishioka S, Sakai P, Maluf Filho F, Melo JM: Endoscopic incision of Zenker's diverticula. Endoscopy 1995;27:433-437.
55.
Benjamin B, Gallagher R: Microendoscopic laser diverticulotomy for hypopharyngeal diverticulum. Ann Otol Rhinol Laryngol 1993;102:675-679.
56.
Van Overbeek JJ: Meditation on the pathogenesis of hypopharyngeal (Zenker's) diverticulum and a report of endoscopic treatment in 545 patients. Ann Otol Rhinol Laryngol 1994;103:178-185.
57.
Von Doersten PG, Byl FM: Endoscopic Zenker's diverticulotomy (Dohlman procedure): forty cases reviewed. Otolaryngol Head Neck Surg 1997;116:209-212.
58.
Harris RP, Weller MD, Porter MJ: A follow-up audit of pharyngeal pouch surgery using endoscopic stapling. Eur Arch Otorhinolaryngol 2010;267:939-943.
59.
Casso C, Lalam M, Ghosh S, Timms M: Endoscopic stapling diverticulotomy: an audit of difficulties, outcome, and patient satisfaction. Otolaryngol Head Neck Surg 2006;134:288-293.
60.
Simic A, Radovanović N, Stojakov D, Bjelovic M, Kotarac M, Sabljak P, Skrobić O, Pesko P: Surgical experience of the national institution in the treatment of Zenker's diverticula. Acta Chir Iugosl 2009;56:25-33.
61.
Jougon J, Dubois G, Delcambre F, Velly JF: Combination of surgical and endoscopic approach for Zenker's diverticulum. Interact Cardiovasc Thorac Surg 2006;5:261-262.
62.
Ruiz-Tovar J, Pérez de Oteyza J, Collado MV, Rojo R, García Villanueva A: 20 years' experience in the management of Zenker's diverticulum in a third-level hospital. Rev Esp Enferm Dig 2006;98:429-435.
63.
Feeley MA, Righi PD, Weisberger EC: Zenker's diverticulum: analysis of surgical complications from diverticulectomy and cricopharyngeal myotomy. Laryngoscope 1999;109:858-861.
64.
Crescenzo D, Trastek V, Allen M, Deschamps C, Pairolero P: Zenker's diverticulum in the elderly: is operation justified? Ann Thorac Surg 1998;66:347-350.
65.
Bonafede J, Lavertu P, Wood B, Eliachar I: Surgical outcome in 87 patients with Zenker's diverticulum. Laryngoscope 1997;107:720-725.
66.
Nguyen H, Urquhart A: Zenker's diverticulum. Laryngoscope 1997;107:1436-1440.
67.
Ellis FH Jr, Gibb SP, Williamson WA: Current status of cricopharyngeal myotomy for cervical esophageal dysphagia. Eur J Cardiothorac Surg 1996;10:1033-1038.
68.
Cerdan FO, Gonzalez EM, Garcia DH: Diagnostic and treatment of Zenker's diverticulum; review of our series pharyngoesophageal diverticula. Hepatogastroenterology 1998;45:447-450.
69.
Brouillette D, Martel E, Chen LQ, Duranceau A: Pitfalls and complications of cricopharyngeal myotomy. Chest Surg Clin N Am 1997;7:457-475.
70.
Lindgren S, Ekberg O: Cricopharyngeal myotomy in the treatment of dysphagia. Clin Otolaryngol 1990;15:221-227.
71.
Barthlen W, Feussner H, Hannig CH, Holscher AH, Siewert JR: Surgical therapy of Zenker's diverticulum: low risk and high efficiency. Dysphagia 1990;5:13-19.
72.
Morton R, Bartley J: Inversion of Zenker's diverticulum: the preferred option. Head Neck 1993;15:253-256.
73.
Laccourreye O, Menard M, Cauchois R: Esophageal diverticulum: diverticulopexy versus diverticulectomy. Laryngoscope 1994;104:889-892.
74.
Colombo-Benkmann M, Unruh V, Krieglstein C, Senninger N: Cricopharyngeal myotomy in the treatment of Zenker's diverticulum. J Am Coll Surg 2003;196:370-377.
75.
Laing MR, Murthy P, Cockburn SW: Surgery for pharyngeal pouch: audit of management with short- and long-term follow up. J R Coll Surg Edinb 1995;40:315-318.
76.
Brigand C, Ferraro P, Martin J, Duranceau A: Risk factors in patients undergoing cricopharyngeal myotomy. Br J Surg 2007;94:978-983.
77.
Muñoz AA, Shapiro J, Cuddy LD, Misono S, Bhattacharyya N: Videofluoroscopic findings in dysphagic patients with cricopharyngeal dysfunction: before and after open cricopharyngeal myotomy. Ann Otol Rhinol Laryngol 2007;116:49-56.
78.
Schmit PJ, Zuckerbraun L: Treatment of Zenker's diverticulum by cricopharyngeus myotomy under local anesthesia. Am Surg 1992;58:710-716.
79.
Payne WS: The treatment of pharyngoesophageal diverticulum: the simple and complex. Hepatogastroenterology 1992;39:109-114.
80.
Aggerholm K, Illum P: Surgical treatment of Zenker's diverticulum. J Laryngol Otol 1990;104:312-314.
81.
Lerut T, van Raemdonck D, Guelinckx P, Dom R, Geboes K: Zenker's diverticulum: is a myotomy of the cricopharyngeus useful? How long should it be? Hepatogastroenterology 1992;39:127-131.
82.
Mortensen M, Schaberg MR, Genden EM, Woo P: Transoral resection of short segment Zenker's diverticulum and cricopharyngeal myotomy: an alternative minimally invasive approach. Laryngoscope 2010;120:17-22.
83.
Lang RA, Spelsberg FW, Winter H, Jauch KW, Hüttl TP: Transoral diverticulostomy with a modified Endo-Gia stapler: results after 4 years of experience. Surg Endosc 2007;21:532-536.
84.
Zaninotto G, Narne S, Costantini M, Molena D, Cutrone C, Portale G: Tailored approach to Zenker's diverticula. Surg Endosc 2003;17:129-133.
85.
Mirza S, Dutt SN, Minhas SS, Irving RM: A retrospective review of pharyngeal pouch surgery in 56 patients. Ann R Coll Surg Engl 2002;84:247-251.
86.
Keck T, Rozsasi A, Grün PM: Surgical treatment of hypopharyngeal diverticulum (Zenker's diverticulum). Eur Arch Otorhinolaryngol 2010;267:587-592.
87.
Rizzetto C, Zaninotto G, Costantini M, Bottin R, Finotti E, Zanatta L, Guirroli E, Ceolin M, Nicoletti L, Ruol A, Ancona E: Zenker's diverticula: feasibility of a tailored approach based on diverticulum size. J Gastrointest Surg 2008;12:2057-2064.
88.
Bonavina L, Bona D, Abraham M, Saino G, Abate E: Long-term results of endosurgical and open surgical approach for Zenker diverticulum. World J Gastroenterol 2007;13:2586-2589.
89.
Wirth D, Kern B, Guenin MO, Montali I, Peterli R, Ackermann C, von Flue M: Outcome and quality of life after open surgery versus endoscopic stapler-assisted esophagodiverticulostomy for Zenker's diverticulum. Dis Esophagus 2006;19:294-298.
90.
Chang CW, Burkey BB, Netterville JL, Courey MS, Garrett CG, Bayles SW: Carbon dioxide laser endoscopic diverticulotomy versus open diverticulectomy for Zenker's diverticulum. Laryngoscope 2004;114:519-527.
91.
Smith SR, Genden EM, Urken ML: Endoscopic stapling technique for the treatment of Zenker diverticulum vs. standard open-neck technique: a direct comparison and charge analysis. Arch Otolaryngol Head Neck Surg 2002;128:141-144.
92.
Gutschow CA, Hamoir M, Rombaux P, Otte JB, Goncette L, Collard JM: Management of pharyngoesophageal (Zenker's) diverticulum: which technique? Ann Thorac Surg 2002;74:1677-1682.
93.
Sydow BD, Levine MS, Rubesin SE, Laufer I: Radiographic findings and complications after surgical or endoscopic repair of Zenker's diverticulum in 16 patients. AJR Am J Roentgenol 2001;177:1067-1071.
94.
Van Eeden S, Lloyd RV, Tranter RM: Comparison of the endoscopic stapling technique with more established procedures for pharyngeal pouches: results and patient satisfaction survey. J Laryngol Otol 1999;113:237-240.
95.
Siddiq MA, Patel PJ: Pharyngeal pouch surgery: a five-year review. Rev Laryngol Otol Rhinol (Bord) 2000;121:37-40.
96.
Zbaren P, Schar P, Tschopp L: Surgical treatment of Zenker's diverticulum: transcutaneous diverticulectomy versus microendoscopic myotomy of the cricopharyngeal muscle with CO2 laser. Otolaryngol Head Neck Surg 1999;121:482-487.
97.
Lippert BM, Folz BJ, Gottschlich S, Werner JA: Microendoscopic treatment of the hypopharyngeal diverticulum with the CO2 laser. Lasers Surg Med 1997;20:394-401.
98.
Brace M, Taylor SM, Trites JR, Bethune D, Attia E, Hart RD: Endoscopic stapling versus external transcervical approach for the treatment of Zenker diverticulum. J Otolaryngol Head Neck Surg 2010;39:102-106.
99.
Safdar A, Curran A, Timon CV: Endoscopic stapling vs. conventional methods of surgery for pharyngeal pouches: results, benefits and modifications. Ir Med J 2004;97:75-76.
100.
Zaninotto G, Rizzetto C: Optimal therapy for cricopharyngeal diverticula; in Ferguson MK (ed): Difficult Decision in Thoracic Surgery: An Evidence-Based Approach, ed 2. London, Springer, 2011, pp 293-301.
101.
Yip HT, Leonard R, Kendall KA: Cricopharyngeal myotomy normalizes the opening size of the upper esophageal sphincter in cricopharyngeal dysfunction. Laryngoscope 2006;116:93-96.
102.
Shaw DW, Cook IJ, Jamieson GG: Influence of surgery on deglutitive upper oesophageal sphincter mechanics in Zenker's diverticulum. Gut 1996;38:806-811.
103.
Zuckerbraun L, Bahna MS: Cricopharyngeus myotomy as the only treatment for Zenker diverticulum. Ann Otol Rhinol Laryngol 1979;88:798-803.
104.
Ellis FH, Schlegel JF, Lynch VP, Payne WS: Cricopharyngeal myotomy for pharyngoesophageal diverticulum. Ann Surg 1969;170:340-349.
105.
Skinner KA, Zuckerbraun L: Recurrent Zenker's diverticulum: treatment with cricopharyngeal myotomy. Am Surg 1998;64:192-195.
106.
Lund WS: The cricopharyngeal sphincter: its relationship to the relief of pharyngeal paralysis and the surgical treatment of the early pharyngeal pouch. J Laryngol Otol 1968;82:353-367.
107.
Williams RB, Ali GN, Hunt DR, Wallace KL, Cook IJ: Cricopharyngeal myotomy does not increase the risk of esophagopharyngeal acid regurgitation. Am J Gastroenterol 1999;94:3448-3454.
108.
Skrobić OM, Simić AP, Radovanović NS, Spica BV, Pesko PM: Current concepts in the anatomy and origin of pharyngeal diverticula. Acta Chir Iugosl 2009;56:17-24.
109.
Lang I, Shaker M: Anatomy and physiology of the upper esophageal sphincter. Am J Med 1997;103:50S-55S.
110.
Kos MP, David EF, Klinkenberg-Knol EC, Mahieu HF: Long-term results of external upper esophageal sphincter myotomy for oropharyngeal dysphagia. Dysphagia 2010;25:169-176.
111.
Duranceau A, Rheault MJ, Jamieson GG: Physiologic response to cricopharyngeal myotomy and diverticulum suspension. Surgery 1983;94:655-662.
112.
Bowdler DA, Stell PM: Surgical management of posterior pharyngeal pulsion diverticula: inversion versus one-stage excision. Br J Surg 1987;74:988-990.
113.
Freeland AP, Bates GJ: The surgical treatment of a pharyngeal pouch: inversion or excision? Ann R Coll Surg Engl 1987;69:57-58.
114.
Wychulis AR, Gunnlaugsson GH, Clagett OT: Carcinoma occurring in pharyngoesophageal diverticulum: report of 3 cases. Surgery 1969;66:976-979.
115.
Dohlman G, Mattsson O: The endoscopic operation for hypopharyngeal diverticula: a roentgen cinematographic study. AMA Arch Otolaryngol 1960;71:744.
116.
Ferreira LE, Simmons DT, Baron TH: Zenker's diverticula: pathophysiology, clinical presentation, and flexible endoscopic management. Dis Esophagus 2008;21:1-8.
© 2013 S. Karger AG, Basel
2013
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.