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* Zenker's diverticula (ZD) is thought to be due to the result of motor abnormalities of the esophagus.  
* Zenker's diverticula (ZD) is thought to be due to the result of motor abnormalities of the esophagus.  
* ZD emerge from a defect within the  Killian's triangle that's a natural place for the weak point of the muscular wall of the hypopharynx.
* ZD emerge from a defect within the  Killian's triangle that's a natural place of weakness on the muscular wall of the hypopharynx.
* Killian's triangle is formed by the oblique fibers of the inferior pharyngeal constrictor muscle and the cricopharyngeal sphincter.  
* Killian's triangle is formed by the oblique fibers of the inferior pharyngeal constrictor muscle and the cricopharyngeal sphincter.  
* This posterior pouch includes only mucosa and submucosa, thus, a ZD should be considered a pseudodiverticulum.
* This posterior pouch includes only mucosa and submucosa, thus, a ZD should be considered a pseudodiverticulum.
* Chronic strain on the Killian's triangle leads to an evagination of the sphincter, which may be because of the following
* Chronic strain on the Killian's triangle leads to an evagination of the sphincter, which may be because of the following
● High pressures in the food bolus in the course of swallowing
● High pressures in the food bolus in the course of swallowing.
● Difficulty in swallowing because of abnormalities of the upper esophageal sphincter (UES)
● Difficulty in swallowing because of abnormalities of the upper esophageal sphincter (UES)
* This failure to achieve adequate diameter for effective bolus clearance leads to a subsequent increase in the hypopharyngeal pressure gradient.
* This failure to achieve adequate diameter for effective bolus clearance leads to a subsequent increase in the hypopharyngeal pressure gradient.
* The consequences of numerous studies illustrate the kinds of observations made in patients with ZD
* A variety of situations predisposing to herniation within Killian's triangle, inclusive of atypical esophageal motility, esophageal shortening, or disorders related to altered u.s.function.  
* A variety of situations predisposing to herniation within Killian's triangle, inclusive of atypical esophageal motility, esophageal shortening, or disorders related to altered u.s.function.  
* Increased intrabolus pressures found in patients with ZD can be secondary to impaired bolus passage in combination with or as a result of gastroesophageal reflux disease.  
* Increased intrabolus pressures found in patients with ZD can be secondary to impaired bolus passage in combination with or as a result of gastroesophageal reflux disease.  
* An unanswered question is how spasms of UES provoked by acid reflux should cause improved intrabolus pressures during swallowing, given that swallowing is often distinct from episodes of acid reflux disorder.
* As the diverticulum enlarges, it may compress the pharyngoesophageal segment as well as increased stiffness and the intrabolus pressure.  
* As the diverticulum enlarges, it may compress the pharyngoesophageal segment as well as increased stiffness and the intrabolus pressure.  
* Increased intrabolus pressure is also increased in older patients who perform multiple swallows to achieve bolus clearance.
* Increased intrabolus pressure is also increased in older patients who perform multiple swallows to achieve bolus clearance.
* Finally, incoordination of pharyngeal contraction and UES opening has also been variably demonstrated by some investigator
* Finally, incoordination of pharyngeal contraction and UES opening has also been variably demonstrated by some investigator
* Various hypothesis involved in the pathogenesis of the Zenker's diverticulum are as follows<ref name="pmid1397879">{{cite journal |vauthors=Cook IJ, Gabb M, Panagopoulos V, Jamieson GG, Dodds WJ, Dent J, Shearman DJ |title=Pharyngeal (Zenker's) diverticulum is a disorder of upper esophageal sphincter opening |journal=Gastroenterology |volume=103 |issue=4 |pages=1229–35 |year=1992 |pmid=1397879 |doi= |url=}}</ref><ref name="pmid1283083">{{cite journal |vauthors=Cook IJ, Blumbergs P, Cash K, Jamieson GG, Shearman DJ |title=Structural abnormalities of the cricopharyngeus muscle in patients with pharyngeal (Zenker's) diverticulum |journal=J. Gastroenterol. Hepatol. |volume=7 |issue=6 |pages=556–62 |year=1992 |pmid=1283083 |doi= |url=}}</ref><ref name="pmid1634178">{{cite journal |vauthors=Fulp SR, Castell DO |title=Manometric aspects of Zenker's diverticulum |journal=Hepatogastroenterology |volume=39 |issue=2 |pages=123–6 |year=1992 |pmid=1634178 |doi= |url=}}</ref><ref name="pmid12928096">{{cite journal |vauthors=Sasaki CT, Ross DA, Hundal J |title=Association between Zenker diverticulum and gastroesophageal reflux disease: development of a working hypothesis |journal=Am. J. Med. |volume=115 Suppl 3A |issue= |pages=169S–171S |year=2003 |pmid=12928096 |doi= |url=}}</ref><ref name="pmid7923848">{{cite journal |vauthors=Resouly A, Braat J, Jackson A, Evans H |title=Pharyngeal pouch: link with reflux and oesophageal dysmotility |journal=Clin Otolaryngol Allied Sci |volume=19 |issue=3 |pages=241–2 |year=1994 |pmid=7923848 |doi= |url=}}</ref><ref name="pmid11715923">{{cite journal |vauthors=Mulder CJ, Costamagna G, Sakai P |title=Zenker's diverticulum: treatment using a flexible endoscope |journal=Endoscopy |volume=33 |issue=11 |pages=991–7 |year=2001 |pmid=11715923 |doi=10.1055/s-2004-826106 |url=}}</ref><ref name="pmid5428852">{{cite journal |vauthors=Hunt PS, Connell AM, Smiley TB |title=The cricopharyngeal sphincter in gastric reflux |journal=Gut |volume=11 |issue=4 |pages=303–6 |year=1970 |pmid=5428852 |pmc=1411416 |doi= |url=}}</ref>
* Various hypothesis involved in the pathogenesis of the Zenker's diverticulum are as follows<ref name="pmid1397879">{{cite journal |vauthors=Cook IJ, Gabb M, Panagopoulos V, Jamieson GG, Dodds WJ, Dent J, Shearman DJ |title=Pharyngeal (Zenker's) diverticulum is a disorder of upper esophageal sphincter opening |journal=Gastroenterology |volume=103 |issue=4 |pages=1229–35 |year=1992 |pmid=1397879 |doi= |url=}}</ref><ref name="pmid1283083">{{cite journal |vauthors=Cook IJ, Blumbergs P, Cash K, Jamieson GG, Shearman DJ |title=Structural abnormalities of the cricopharyngeus muscle in patients with pharyngeal (Zenker's) diverticulum |journal=J. Gastroenterol. Hepatol. |volume=7 |issue=6 |pages=556–62 |year=1992 |pmid=1283083 |doi= |url=}}</ref><ref name="pmid1634178">{{cite journal |vauthors=Fulp SR, Castell DO |title=Manometric aspects of Zenker's diverticulum |journal=Hepatogastroenterology |volume=39 |issue=2 |pages=123–6 |year=1992 |pmid=1634178 |doi= |url=}}</ref><ref name="pmid12928096">{{cite journal |vauthors=Sasaki CT, Ross DA, Hundal J |title=Association between Zenker diverticulum and gastroesophageal reflux disease: development of a working hypothesis |journal=Am. J. Med. |volume=115 Suppl 3A |issue= |pages=169S–171S |year=2003 |pmid=12928096 |doi= |url=}}</ref><ref name="pmid7923848">{{cite journal |vauthors=Resouly A, Braat J, Jackson A, Evans H |title=Pharyngeal pouch: link with reflux and oesophageal dysmotility |journal=Clin Otolaryngol Allied Sci |volume=19 |issue=3 |pages=241–2 |year=1994 |pmid=7923848 |doi= |url=}}</ref><ref name="pmid11715923">{{cite journal |vauthors=Mulder CJ, Costamagna G, Sakai P |title=Zenker's diverticulum: treatment using a flexible endoscope |journal=Endoscopy |volume=33 |issue=11 |pages=991–7 |year=2001 |pmid=11715923 |doi=10.1055/s-2004-826106 |url=}}</ref><ref name="pmid5428852">{{cite journal |vauthors=Hunt PS, Connell AM, Smiley TB |title=The cricopharyngeal sphincter in gastric reflux |journal=Gut |volume=11 |issue=4 |pages=303–6 |year=1970 |pmid=5428852 |pmc=1411416 |doi= |url=}}</ref>
1. Zenker's diverticulum is a disorder of diminished upper esophageal sphincter opening that is not due to pharyngosphincteric incoordination or failed sphincter relaxation. Incomplete sphincter opening is probably to cause dysphagia. increased hypopharyngeal pressures throughout swallowing are probably important in the pathogenesis of the diverticulum.
1.Zenker's diverticulum is a disorder of diminished upper esophageal sphincter opening that is not due to pharyngosphincteric incoordination or failed sphincter relaxation. Incomplete sphincter opening is probably to cause dysphagia. increased hypopharyngeal pressures throughout swallowing are probably important in the pathogenesis of the diverticulum.


2. The cricopharyngeus muscle from patients and controls differed from inferior constrictor muscle by means of the virtue of type 1 fibre predominance and greater fibre size variability. Ragged red fibres and nemaline bodies are a normal finding within the cricopharyngeus. Marked differences were observed in the cricopharyngeus muscle of Zenker's patients which demonstrated fibro-adipose tissue replacement and fibre degeneration. it is concluded that these structural modifications can also account for the observed diminished upper oesophageal sphincter opening and dysphagia in patients with Zenker's diverticulum.
2.The cricopharyngeus muscle from patients and controls differed from inferior constrictor muscle by means of the virtue of type 1 fibre predominance and greater fibre size variability. Ragged red fibres and nemaline bodies are a normal finding within the cricopharyngeus. Marked differences were observed in the cricopharyngeus muscle of Zenker's patients which demonstrated fibro-adipose tissue replacement and fibre degeneration. it is concluded that these structural modifications can also account for the observed diminished upper oesophageal sphincter opening and dysphagia in patients with Zenker's diverticulum.


3. Nineteen patients in the sample were found to have reflux and 20 had dysmotility. These findings suggest that pharyngeal pouches are not a purely localized incoordination of the cricopharyngeal sphincter but are associated with a generalized oesophageal muscle dysfunction.
3.Nineteen patients in the sample were found to have reflux and 20 had dysmotility. These findings suggest that pharyngeal pouches are not a purely localized incoordination of the cricopharyngeal sphincter but are associated with a generalized oesophageal muscle dysfunction.


4. Acid reflux induces longitudinal esophageal shortening, which in turn increases the chance for the development of herniation between 2 spatially associated structures, the pharyngeal constrictors and cricopharyngeus muscles, leading to the development of Zenker diverticulum
4.Acid reflux induces longitudinal esophageal shortening, which in turn increases the chance for the development of herniation between 2 spatially associated structures, the pharyngeal constrictors and cricopharyngeus muscles, leading to the development of Zenker diverticulum


5. Zenker's diverticulum is thought to result from disordered coordination among the pharynx and upper esophageal sphincter. Manometric studies of the upper esophagus were useful in testing the hypothesis of dysmotility in the formation and growth of a Zenker's diverticulum; however, the data have provided conflicting evidence. Manometric studies show that resting upper esophageal sphincter strain is normal in some patients with Zenker's diverticulum and decreased in others. abnormal premature relaxation and contraction of the upper esophageal sphincter seen in some patients with Zenker's diverticulum may be accompanied with the aid of pharyngeal contractions against a closed sphincter. This abnormality is thought by a few investigators to be the cause of Zenker's diverticulum, but not by others who have found normal upper sphincter relaxation.
5.Zenker's diverticulum is thought to result from disordered coordination among the pharynx and upper esophageal sphincter. Manometric studies of the upper esophagus were used in testing the hypothesis of dysmotility in the formation and growth of a Zenker's diverticulum; however, the data have provided conflicting evidence. Manometric studies show that resting upper esophageal sphincter strain is normal in some patients with Zenker's diverticulum and decreased in others. abnormal premature relaxation and contraction of the upper esophageal sphincter seen in some patients with Zenker's diverticulum may be accompanied with the aid of pharyngeal contractions against a closed sphincter. This abnormality is thought by a few investigators to be the cause of Zenker's diverticulum, but not by others who have found normal upper sphincter relaxation.


considering these observations collectively, a reasonable hypothesis for the development of ZD is that it occurs in a variety of circumstances predisposing to herniation within Killian's triangle, inclusive of unusual esophageal motility, esophageal shortening, or disorders associated with altered u.s.function. increased intrabolus pressures observed in patients with ZD may be secondary to impaired bolus passage in combination with or as a result of gastroesophageal reflux disease. An unanswered question is how spasms of the u.s.provoked by acid reflux ought to lead to increased intrabolus pressures during swallowing, given that swallowing is frequently distinct from episodes of acid reflux disease.
All the above-mentioned hypotheses lead to herniation within the Killian's triangle, inclusive of disorders associated with altered UES function, unusual esophageal motility, esophageal shortening.  
<references />
Impaired bolus passage leads to increases intrabolus pressure which leads to herniation in the Killians triangle.  
Acid reflux is thought to lead to increased spasm of the UES which in turn increases the intrabolus pressures during swallowing, given that swallowing is frequently distinct from episodes of acid reflux disease.

Revision as of 19:27, 24 October 2017

  • Zenker's diverticula (ZD) is thought to be due to the result of motor abnormalities of the esophagus.
  • ZD emerge from a defect within the Killian's triangle that's a natural place of weakness on the muscular wall of the hypopharynx.
  • Killian's triangle is formed by the oblique fibers of the inferior pharyngeal constrictor muscle and the cricopharyngeal sphincter.
  • This posterior pouch includes only mucosa and submucosa, thus, a ZD should be considered a pseudodiverticulum.
  • Chronic strain on the Killian's triangle leads to an evagination of the sphincter, which may be because of the following

● High pressures in the food bolus in the course of swallowing. ● Difficulty in swallowing because of abnormalities of the upper esophageal sphincter (UES)

  • This failure to achieve adequate diameter for effective bolus clearance leads to a subsequent increase in the hypopharyngeal pressure gradient.
  • A variety of situations predisposing to herniation within Killian's triangle, inclusive of atypical esophageal motility, esophageal shortening, or disorders related to altered u.s.function.
  • Increased intrabolus pressures found in patients with ZD can be secondary to impaired bolus passage in combination with or as a result of gastroesophageal reflux disease.
  • As the diverticulum enlarges, it may compress the pharyngoesophageal segment as well as increased stiffness and the intrabolus pressure.
  • Increased intrabolus pressure is also increased in older patients who perform multiple swallows to achieve bolus clearance.
  • Finally, incoordination of pharyngeal contraction and UES opening has also been variably demonstrated by some investigator
  • Various hypothesis involved in the pathogenesis of the Zenker's diverticulum are as follows[1][2][3][4][5][6][7]

1.Zenker's diverticulum is a disorder of diminished upper esophageal sphincter opening that is not due to pharyngosphincteric incoordination or failed sphincter relaxation. Incomplete sphincter opening is probably to cause dysphagia. increased hypopharyngeal pressures throughout swallowing are probably important in the pathogenesis of the diverticulum.

2.The cricopharyngeus muscle from patients and controls differed from inferior constrictor muscle by means of the virtue of type 1 fibre predominance and greater fibre size variability. Ragged red fibres and nemaline bodies are a normal finding within the cricopharyngeus. Marked differences were observed in the cricopharyngeus muscle of Zenker's patients which demonstrated fibro-adipose tissue replacement and fibre degeneration. it is concluded that these structural modifications can also account for the observed diminished upper oesophageal sphincter opening and dysphagia in patients with Zenker's diverticulum.

3.Nineteen patients in the sample were found to have reflux and 20 had dysmotility. These findings suggest that pharyngeal pouches are not a purely localized incoordination of the cricopharyngeal sphincter but are associated with a generalized oesophageal muscle dysfunction.

4.Acid reflux induces longitudinal esophageal shortening, which in turn increases the chance for the development of herniation between 2 spatially associated structures, the pharyngeal constrictors and cricopharyngeus muscles, leading to the development of Zenker diverticulum

5.Zenker's diverticulum is thought to result from disordered coordination among the pharynx and upper esophageal sphincter. Manometric studies of the upper esophagus were used in testing the hypothesis of dysmotility in the formation and growth of a Zenker's diverticulum; however, the data have provided conflicting evidence. Manometric studies show that resting upper esophageal sphincter strain is normal in some patients with Zenker's diverticulum and decreased in others. abnormal premature relaxation and contraction of the upper esophageal sphincter seen in some patients with Zenker's diverticulum may be accompanied with the aid of pharyngeal contractions against a closed sphincter. This abnormality is thought by a few investigators to be the cause of Zenker's diverticulum, but not by others who have found normal upper sphincter relaxation.

All the above-mentioned hypotheses lead to herniation within the Killian's triangle, inclusive of disorders associated with altered UES function, unusual esophageal motility, esophageal shortening. Impaired bolus passage leads to increases intrabolus pressure which leads to herniation in the Killians triangle. Acid reflux is thought to lead to increased spasm of the UES which in turn increases the intrabolus pressures during swallowing, given that swallowing is frequently distinct from episodes of acid reflux disease.

  1. ↑ Cook IJ, Gabb M, Panagopoulos V, Jamieson GG, Dodds WJ, Dent J, Shearman DJ (1992). "Pharyngeal (Zenker's) diverticulum is a disorder of upper esophageal sphincter opening". Gastroenterology. 103 (4): 1229–35. PMID 1397879.
  2. ↑ Cook IJ, Blumbergs P, Cash K, Jamieson GG, Shearman DJ (1992). "Structural abnormalities of the cricopharyngeus muscle in patients with pharyngeal (Zenker's) diverticulum". J. Gastroenterol. Hepatol. 7 (6): 556–62. PMID 1283083.
  3. ↑ Fulp SR, Castell DO (1992). "Manometric aspects of Zenker's diverticulum". Hepatogastroenterology. 39 (2): 123–6. PMID 1634178.
  4. ↑ Sasaki CT, Ross DA, Hundal J (2003). "Association between Zenker diverticulum and gastroesophageal reflux disease: development of a working hypothesis". Am. J. Med. 115 Suppl 3A: 169S–171S. PMID 12928096.
  5. ↑ Resouly A, Braat J, Jackson A, Evans H (1994). "Pharyngeal pouch: link with reflux and oesophageal dysmotility". Clin Otolaryngol Allied Sci. 19 (3): 241–2. PMID 7923848.
  6. ↑ Mulder CJ, Costamagna G, Sakai P (2001). "Zenker's diverticulum: treatment using a flexible endoscope". Endoscopy. 33 (11): 991–7. doi:10.1055/s-2004-826106. PMID 11715923.
  7. ↑ Hunt PS, Connell AM, Smiley TB (1970). "The cricopharyngeal sphincter in gastric reflux". Gut. 11 (4): 303–6. PMC 1411416. PMID 5428852.
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