Int J Gastrointest Interv 2020; 9(2): 78-85
Published online April 30, 2020 https://doi.org/10.18528/ijgii200004
Copyright © International Journal of Gastrointestinal Intervention.
Department of Gastroenterology, Asian Institute of Gastroenterology, Hyderabad, India
Correspondence to:* Department of Gastroenterology, Asian Institute of Gastroenterology, 6-3-661 Somajiguda, Hyderabad, Telangana 500082, India.
E-mail address: email@example.com (Z. Nabi).
This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Zenker’s diverticulum (ZD) is a rare condition that predominantly effects elderly population. Dysphagia and regurgitation are the common presenting symptoms in patients with ZD. Flexible endoscopic diverticulotomy (FED) of the cricopharyngeal septum is the mainstay of management in symptomatic ZD. The outcomes of FED compare favorably to open surgical and trans-oral rigid endoscopic treatment methods. Moreover, FED is associated with relatively fewer morbidities as compared to surgery. Bleeding and micro-perforation are the most commonly reported immediate adverse events. Majority of the adverse events are mild and severe adverse events are rare with FED. Recurrence of symptoms remain the most important long-term concern after FED. Nevertheless, majority of the recurrences respond to a repeat session of endoscopic treatment. Lately, new electrosurgical knives and novel endoscopic techniques of cricopharyngeal myotomy have been evaluated for the treatment of ZD. Novel techniques include double incision with snare resection and submucosal tunneling endoscopic septum division. The proposed advantage with these techniques is possible reduced incidence of recurrences after endoscopic treatment. Randomized comparison studies are required between new and conventional flexible endoscopic techniques. In addition, standardized reporting of clinical success, and adverse events is required in future studies.
Keywords: Endoscopy, Myotomy, Zenker diverticulum
Zenker’s diverticulum (ZD) is a rare pulsion type diverticulum that develops at pharyngoesophageal junction and usually manifests in seventh or eighth decade of life.1 The diagnosis of ZD is established with gastroscopy and oral contrast or barium swallow study. The latter is especially useful in defining the size and dimensions of the diverticulum (Fig. 1). Majority of the symptomatic patients present with dysphagia, regurgitation, halitosis or chronic cough. The severity of symptoms can be assessed objectively by several assessment tools like Dakkak and Bennett scale, Swallowing-Quality of Life, and Eating Assessment Tool.2
The management options of ZD include surgery, rigid endoscopy and flexible endoscopic diverticulotomy (FED). Over the last several decades, FED has emerged as a safe and effective alternative to surgery. The advantages of flexible endoscopic treatment over open surgery include comparable outcomes, reduced morbidity and flexibility to perform under deep sedation.
Endoscopic treatment of symptomatic ZD has been established as a safe and effective treatment option with fewer morbidities as compared to surgery.3 Endoscopic treatment methods include rigid and flexible endoscopic division of septum. The rigid transoral approach requires the placement of a rigid diverticuloscope followed by division of the cricopharyngeal septum using carbon dioxide laser or a stapling device. The major limitations of rigid endoscopy include requirement of general anaesthesia, and relative contraindication in those with limited cervical spine mobility and small size diverticulae (< 3 cm). For the same reason, FED is increasingly being utilized and preferred over rigid endoscopy techniques.
The procedure of FED requires a high definition flexible endoscope (preferably the one equipped with water jet), transparent hood, soft diverticuloscope, electrosurgical knife, electrosurgical generator, CO2 insufflator, coagulation forceps, guidewire, and nasogastric tube. The use of diverticuloscope to stabilize the septum is optional and depends on the operator’s preference (Fig. 2). The division of cricopharyngeal septum is performed by an electrosurgical knife. The choice of electrosurgical knife is largely operator dependent. Different knives described in literature for ZD include needle knife, hook knife, scissor type knives, and triangular knife (Fig. 3).4–19 Of these, needle knife and hook knife are the most commonly utilized. Hook knife may be especially useful as it allows pulling of the muscle fibers for precise cutting and reduces the chances of inadvertent deep injury at the bottom of the septum.6 In addition, FED has also been performed using harmonic scalpels, LigaSure device and the stapling device.18,20–22 The latter three devices have not been designed specifically for flexible endoscopic use and are required to be passed alongside the endoscope rather than the endoscope channel. Irrespective of the knife or the technique utilized, flexible endoscopic treatment aims at near complete division of the cricopharyngeal septum and minimize complications.
Table 1 describes the different types of knives and the settings on electrosurgical generator used in various studies.
Table 1 . Types of Knives and Electrosurgical Settings Used in Studies (Selected).
|Needle knife8||Endo-Flex (Voerde, Germany)||Length: 1.8 mm||Endocut I mode, effect 3, 100 W cutting, 40 W coagulation|
|Zimmon Needle (Cook Endoscopy, Winston-Salem, NC, USA)||Auto cut effect 4|
|Hook knife19||KD-620 LR; Olympus, Tokyo, Japan||Length: 4.5 mm; diameter: 0.4 mm; hook length: 1.3 mm||Endocut, effect 2, duration 2, interval 3, and forced coagulation effect 2, power 40 W|
|Clutch Cutter knife16||Fujifilm Co., Tokyo, Japan||0.4 × 3.5 or 5 mm||Forced coagulation 30 W, Endo Cut Q with effect 1, duration 3, interval 1|
|Stag Beetle (SB) knife13||Sumitomo Bakelite Co., Tokyo, Japan||SB: 7 mm; SB Jr: 3.5 mm||Endo Cut Q Effect 1|
|Soft Coagulation 40 W|
|Triangular tip knife30||KD-645L; Olympus, Tokyo, Japan||4.5 × 0.4 mm||Diverticulotimy: Spray Coag, effect 2, 40 W|
|Coagulation: Soft Coag, effect 5, 80 W|
The technique of FED is not standardized and considerable variations exist in practice. The procedure can be performed under general anaesthesia or deep sedation using propofol. The steps of FED in our unit are as follows: 1) cleansing of the diverticulum of all the food debris (Fig. 4A); 2) placement of a soft diverticuloscope (ZDO-22/30; Cook Medical, Limerick, Ireland) so that the longer limb occupies the esophageal lumen and the shorter limb fits into the diverticulum (Fig. 4B); 3) gradual withdrawal of the endoscope to check the optimal position of the diverticuloscope; 4) incision of the mucosa over the septum followed by septotomy using an electrosurgical knife (Fig. 3B); 5) division of the septum till the visualization of the muscle fibers at the bottom of the septum (Fig. 4C); 6) prophylactic placement of one or more endoclips at the base of the cut end of septum (Fig. 4D).
In case, a diverticuloscope is not used (small diverticulum < 2–3 cm or operator’s preference) a distal transparent cap is often attached to the tip of endoscope for better visualization and separation of myotomy edges. A nasogastric tube placed over the guidewire is also useful as it guides the direction of myotomy, improves the visualization of the septum and protects the contralateral esophageal mucosa from thermal injury.6 In addition, it provides for the feeding route in case of an inadvertent perforation.
The outcomes of FED are mainly dependent on the operator’s experience and the size of the diverticulum. These factors partly explain the wide range of reported clinical success which ranges from 60%–100% in the published literature.23 Majority of the recent studies reveal a success rate of 80%–90% (Table 2). Whether, the difference in the technique used for FED impacts the incidence of recurrences is debatable. Some experts extend the myotomy beyond the tip of the diverticulum.14 Whereas, others avoid a complete myotomy to reduce the risk of perforation.11 The argument in favor of the latter approach is that reasonable outcomes can be achieved with a second session of endotherapy in cases with recurrence. However, regardless of the technique used recurrent symptoms have been reported in up to 20%–25% of patients after flexible endoscopic treatment. Majority of the recurrences are still amenable to a repeat flexible endoscopy treatment. In a large study (
Table 2 . Selected Studies Reporting the Outcomes of Flexible Endoscopic Myotomy in Zenker’s Diverticulum.
|Study||Number||Age (yr)*||Size (cm)*||Knife||Procedure time (min)*||Adverse event†||Recurrence/success†||Follow-up (mo)*|
|Vogelsang et al (2007)4||31||69 (52–92)||3.7||Needle knife||NR||23% (minor)||Recurrence: 39% (single treatment)||26 (14–49)|
|Al-Kadi et al (2010)5||18||80 (68–91)||NR||Needle knife||28.4 (10–60)||1 (microperforation)||Recurrence: 2||27.5 (0.5–84)|
|Repici et al (2010)6||32||74.8||< 3: 6||Hook knife||28 (22–45)||6.25%||Success: 90.6%||23.87 ± 9.6|
|> 4: 16|
|Case and Baron (2010)7||22||84.5 (59–96)||NR||Needle knife||NR||27% (perforation)||Success: 82%||12.7 ± 9.2|
|Huberty et al (2013)8||150||73 (42–94)||3 (1–8)||Needle knife||NR||2.2%||Recurrence: 23.1%||43 (13–121)|
|Battaglia et al (2015)9||31||71 (52–85)||3 (1–8)||Stag Beetle (SB) knife||14 (11–23)||1 (bleeding)||Recurrence: 2||7 (2–18)|
|Halland et al (2016)10||52||77 (34–97)||2.8 (1–5)||Needle knife and Hook knife||NR||Mild: 16%||Recurrence: 23%||26 (0.5–68)|
|Brueckner et al (2016)11||46||67 (40–85)||NR||Hook knife||NR||Bleeding: 3||Recurrence: 30%||39 (18–73)|
|Costamagna et al (2016)12||89||70 (42–94)||3.0 (1.5–11)||Needle knife||15 (7–45)||Perforation: 2%||Recurrence: 36%||32 (1–98)|
|Goelder et al (2016)13||52||71 (42–86)||3 (1–5)||SB knife||32 (18–60)||No major complication||Success: 90% (single session)||16 (2–31)|
|Pescarus et al (2016)14||26||74.9 (47.3–96.7)||2.8 (1–5)||Needle or Hook knife||68 (28–149)||Leak: 1 patient||Recurrence: 11.5%||21.8 (1–68.2)|
|Dişibeyaz et al (2017)15||17||65.3||3.2 (2–5)||Needle knife||NR||17.6%||Recurrence: 23.5%||47.7 (14–104)|
|Rath et al (2018)16||21||74.9 (47.3–96.7)||1.5–5.6||Clutch Cutter||19 (CC)||Minor bleed: 1||Recurrence: 1||12|
|CC: 6||Needle knife||43 (NK)||Delayed bleed: 1|
|NK: 15||Cervical emphysema: 3|
|Fan et al (2019)17||9||77 (66–85)||NR||Needle knife||36 (14–65)||None||Recurrence: 7||11 (2–46)|
|Diez Redondo et al (2019)18||69||73.4 (46–93)||2.8 (1–5)||Ligasure||22 (11–48)||Microperforation: 2.5||Success: 84%||34.6 (24–64)|
|Delayed bleed: 1.3|
CC, clutch cutter; NK, needle knife; NR, not reported..
*Values are presented as median (range) or mean only unless otherwise indicated..
†Values are presented as percent or number..
FED is a safe procedure and major adverse events are rare. Intraprocedural bleeding is common but endoscopic coagulation is sufficient in vast majority of the cases. Perforation occurs in about 4% cases and is the most dreaded complication associated with FED.1 In a systematic review, the median rate of overall adverse events and perforation was 14.1% and 6.5% (0%–27.3%), respectively. In our practice, we routinely place endoclips after completion of the divertculotomy to reduce delayed bleeding and perforation. However, this is not evidence based and randomized comparison studies are warranted. The use of diverticuloscope was shown to reduce the incidence of perforations when compared to the cap assisted technique in one non-randomized study.26
It is important to note that technique of FED is not standardized and considerable variation exists in clinical practice. In addition, majority of the studies did not use a standardized definition to classify the adverse events. Therefore, it may not be feasible to compare the incidences of adverse events in different studies.
Majority of the studies have reported the use of needle knife or hook knife for diverticulotomy (Fig. 3A, 3C). More recently, the use of scissor type knives has been described for FED. These include the Clutch Cutter knife (CC knife; Fujifilm Co., Tokyo, Japan) and the Stag Beetle knife (SB knife; Sumitomo Bakelite Co., Tokyo, Japan).13,16,27,28 The utility of these knives has been demonstrated in endoscopic submucosal dissection for early gastrointestinal neoplasms.
CC knife has monopolar blades and serrated cutting edges (Fig. 3D). The outer surface is insulated which avoids collateral thermal injury. This knife is rotatable and available in two sizes i.e., 3.5 mm and 5.0 mm.29 Rath et al16 described the use of CC knife in six cases with symptomatic ZD. The procedure could be successfully completed in all the patients and there were no major complications. Importantly, the mean procedure duration was only 19 minutes with CC knife as compared to 43 minutes in the needle knife group.16
SB knife is similar to the CC knife in terms of monopolar blades and external insulation (Fig. 3B). Currently, three types of SB knives are available i.e., SB knife (standard: 7 mm, short: 6 mm), SB Jr (3.5 mm), and SB GX (6 mm). The latter has partially serrated edges. As compared to CC knife, these knives are slimmer and do not have serrated edges (SB and SB Jr).29 Several recent studies have described the use of this knife in cricopharyngeal dicrticulotomy.9,13,28 Goelder et al13 performed diverticulotomy in fifty two patients with ZD (mean size: 3 cm). There were no major complications and majority (90%) of the patients required a single session of myotomy. The proposed advantages of scissor type knives include precise control over the depth of cutting and coagulation using the same device.9
Our group recently described the use of a triangular knife (Triangle tip knife J, KD-645L; Olympus, Tokyo, Japan) in the flexible endoscopic treatment of ZD (Fig. 3E).30 Triangular knife has been primarily utilized for submucosal tunneling procedures like per-oral endoscopic myotomy (POEM) in patients with achalasia cardia.31 The cutting knife length and diameter are 4.5 × 0.4 mm. While, the length and thickness of triangular tip are 0.4 mm and 0.3 mm, respectively. This knife has L-shaped hook in three directions which avoids the need to rotate the knife and enables quick division of muscle fibers. While using this knife, the median procedure duration was only 12 minutes (8–16 minutes) in our study.30
The main drawback of conventional FED is high incidence of symptom recurrences on follow-up. In an attempt to improve the outcomes of FED, several new techniques have been evaluated recently. In the following section, we briefly discuss some of these innovations in the flexible endoscopic management of ZD (Table 3).
Table 3 . Novel Endoscopic Techniques for Zenker’s Diverticulum.
|Study||Number||Size (mm)*||Technique||Procedure time (min)*||Success/recurrence†||Follow-up*|
|Gölder et al (2018)32||16||20 (5–40)||Double incision and snare resection||28 (20–47)||Recurrence: 1||3 mo (1–15 mo)|
|Pang et al (2019)33||20||38||Double incision and snare resection||56||No recurrence||19.1 mo|
|Yang et al (2020)41||75||31.3 (10–89)||Z-POEM/STESD||52.4||Recurrence: 3.2%||291.5 days|
|Repici et al (2020)42||20||17.5||Z-POEM||13.8||No recurrence||12 mo (6–20 mo)|
Z-POEM, Zenker’s per-oral endoscopic myotomy; STESD, submucosal tunneling endoscopic submucosal dissection..
*Values are presented as median (range) or mean only..
†Values are presented as number or percent..
In an attempt to reduce recurrence, Gölder et al32 described a novel technique involving double incision followed by snare resection in sixteen patients with symptomatic ZD. This technique involves parallel incisions with a needle knife or hook knife followed by excision of the cricopharyngeal muscle using a snare (Fig. 5). With this technique, the authors reported only one recurrence at a median follow-up of 3 months. However, small number of patients and a short follow-up duration were the main drawbacks of the study. In a more recent study, Pang et al33 reported the twenty cases with this technique and compared the outcomes with 44 cases in whom the traditional technique of myotomy was utilized. On follow-up, no recurrences were noticed in the myectomy group as compared to a recurrence rate of 22.7% in the standard FED group. There was no significant difference in the procedure duration or rate of adverse events between the two groups.33 The proposed advantage of this technique is that by establishing a wider communication between the diverticulum and the esophageal lumen chances of delayed recurrences are minimized. Given the excellent outcomes and safety profile of this technique, long-term follow-up studies and randomized comparison with the established techniques are warranted.
Submucosal tunneling technique or third space endoscopy has been widely utilized for various indications including achalasia cardia, sub-epithelial tumors, esophageal epiphrenic diverticulum, and refractory gastroparesis.34 More recently, submucosal tunneling has been reported in the management of ZD.35–39 This technique, also called as Z-POEM or submucosal tunneling endoscopic septal division, is essentially similar to the one used for achalasia cardia and epiphrenic esophageal diverticulum.39 Initially a mucosal bleb is created 1–2 cm proximal to the cricopharyngeal septum using indigocarmine diluted with saline (Fig. 6A, 6B). Alternatively, the mucosal bleb and incision can be created directly above the septum in cases with difficult anatomy.39,40 Subsequently, a small mucosal incision is made and submucosal tunnel created (Fig. 6C). Once the septum is reached, the submucosal tunnel is extended towards both the sides of the septum (Fig. 6D). A myotomy is then performed till the distal extent of septum. Finally, the mucosal incision is closed with standard endoclips (Fig. 6F). The proposed advantage of this technique is reduced chances of recurrence due to complete division of the septum. A recent multicenter, retrospective study reported the outcomes of Z-POEM in 75 patients with ZD.41 The mean size of the diverticulum was 31.3 ± 1.6 mm (range, 10–89 mm). Technical and clinical success were recorded in 97.3% and 92% of patients, respectively. Adverse events including bleeding and perforation were uncommon and occurred in 6.7% patients.41 In another study, Repici et al42 evaluated the outcome of endoscopic septotomy in twenty patients with short septum (≤ 20 mm) ZD. Technical and clinical success were 100% and 95%, respectively. There were no adverse events. While, this technique appears promising, the long-term results and comparison with standard technique of diverticulotomy remain to be seen. In addition, this technique may be difficult in patients with recurrent symptoms after prior FED due to submucosal fibrosis.
FED is the preferred treatment for the treatment of symptomatic ZD in the current era. The procedure of FED involves the division of cricopharyngeal septum using an electrosurgical knife. However, the technique of FED is not standardized and variations exist among different centers. Regardless of the technique or devices used, FED has been shown to be a safe and efficacious treatment for ZD. Recurrence of symptoms is the ‘Achilles heel’ of FED. Recent innovations in the devices as well as the techniques are likely to improve the outcomes of FED. Comparison of the newly available knives and techniques are required before concluding their superiority over the conventional methods of FED (Table 4).
Table 4 . Current Techniques for the Endoscopic Management of Zenker’s Diverticulum.
|Procedure characteristic||Conventional technique||Double incision and snare resection32,33||Z-POEM/STESD41,42|
|Procedure duration (min)||14–68||28–56||13.8–52.4|
|Advantages||Largest data on outcomes, technically not demanding, major adverse events, short procedure duration, uncommon, recurrences can be treated with same technique||High success rate, low recurrence rate, no special accessory required||Essentially similar to POEM, good efficacy, low rate of adverse events, complete division of septum can be achieved|
|Drawbacks||High recurrence after single treatment, technique not standardized||Difficult in shallow/small diverticulum, limited data (only two studies), long term results remain to be seen||Limited data, technical difficulty if not performing submucosal endoscopy, pouch mucosa not cut which may lead to recurrences, no comparative studies|
Z-POEM, Zenker’s per-oral endoscopic myotomy; STESD, submucosal tunneling endoscopic submucosal dissection..
No potential conflict of interest relevant to this article was reported.
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