Literature Review: Enlarged Tracheoesophageal Puncture after Total Laryngectomy: A Systematic Review and Meta-Analysis

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Affiliation

Date

ABSTRACT
Objectives: Enlargement of the tracheoesophageal puncture (TEP) is a challenging complication after laryngectomy with TEP. We sought to estimate the rate of enlarged puncture, associated pneumonia rates, potential risk factors, and conservative treatments excluding complete surgical TEP closure.
Methods: A systematic review was conducted (1978–2008). A summary risk estimate was calculated using a random-effects meta-analysis model.
Results: Twenty-seven peer-reviewed manuscripts were included. The rate of enlarged puncture and/or leakage around the prosthesis was reported in 23 articles (range, 1% to 29%; summary risk estimate, 7.2%; 95% confidence interval [CI], 4.8% to 9.6%). Temporary removal of the prosthesis and TEP- site injections were the most commonly reported conservative treatments. Prosthetic diameter (p =.076) and timing of TEP (p = .297) were analyzed as risk factors; however, radiotherapy variables were inconsistently reported.
Conclusions: The overall risk of enlarged puncture seems relatively low, but it remains a rehabilitative challenge. Future research should clearly establish risk factors for enlarged puncture and optimal conservative management.
Keywords: tracheoesophageal puncture, total laryngectomy, enlarged tracheoesophageal puncture, complications, leakage

Enlarged Tracheoesophageal Puncture after Total Laryngectomy: A Systematic Review and Meta-Analysis
Introduction:
The gold standard for voice restoration after total laryngectomy is tracheoesophageal puncture (TEP). The TEP is a small surgically created fistula in the tracheoeosphageal (TE) wall that may be created at the time of the total laryngectomy (primary TEP) or later after the patient has healed from surgery (secondary TEP). A one-way valved silicone voice prosthesis (VP) is placed into the TEP. The prosthetic valve opens to allow pulmonary air into the vocal tract for vibratory sound production when the tracheostoma is occluded, but remains closed to prevent aspiration of foods/liquids during swallowing.1,2 [1]
One of the most difficult complications to manage after TEP is enlargement of the TE fistula that results in aspiration of saliva, liquid, and/or food around the VP into the trachea. Tissue changes associated with radiation, malnourishment, diabetes, smoking, and hypothyroidism may reduce elasticity and integrity of the TEP and have been implicated as potential risk factors for enlarged puncture.3–6 Development of an enlarged TEP has also been associated with acute infection or tumor recurrence.3,7 However, the actual contribution of these potential risk factors is unclear.
An enlarged TEP intuitively increases the risk of pneumonia and respiratory complications due to frequent aspiration around the VP. Reduced tissue elasticity also increases the likelihood of spontaneous dislodgement of the VP and consequently the potential for aspiration of the prosthesis. Various treatments, including surgical closure of the TEP, have been proposed to mitigate the ill-effects of an enlarged TEP. Although surgical closure eliminates problems associated with leakage around the prosthesis, closure of the TEP prevents TE voice production, thus negatively impacting quality of life. Because of this, conservative methods, either surgical or nonsurgical, that aim to eliminate leakage around the VP while preserving functional TE voice, either surgical or nonsurgical but excluding complete TEP closure, are of particular interest. Although a variety of conservative treatments have been proposed, there are no clear guidelines for the conservative management of this complication.[2]
A better understanding of factors associated with enlarged TEP will lead to more uniform assessment and management of this complication, and may guide preventive efforts..[3]
Materials and Methods:
Search Methods:
The search for this systematic review was conducted from May through July2008. The primary search was conducted using the electronic MEDLINE database (data source: OVID). The search was limited to human subject research in peer-reviewed journal articles published between 1978 and June (week 1) 2008. Medical subject heading (MeSH) terms were used to identify articles pertaining to 3 conceptual groups of references: (1) total laryngectomy, (2) TEP/alaryngeal voice restoration, and (3) complications. Within concept 1 (“total laryngectomy”), the following MeSH terms were ‘exploded’ to include all subject headings under the term: Laryngectomy, Laryngeal Neoplasms/Surgery. A total of 10,417 articles were identified in concept 1. These terminologies also identified extended procedures that included pharyngeal resection and use of flap reconstructions. Within concept 2 (“TEP/alaryngeal voice restoration”), the following MeSH terms and subheadings were exploded: Larynx, Artificial; Speech, Alaryngeal; Tracheoesophageal Fistula/Rehabilitation, Surgery; Laryngeal Neoplasms/Rehabilitation; Prosthesis Implantation/Rehabilitation, Methods; Laryngectomy/Rehabilitation. A total of 15,178 articles were identified in concept 2. Within concept (“complications”), the following MeSH terms and subheadings were exploded: Punctures/Adverse Effects, Classification, Complications; Prostheses and Implants/Adverse Effects, Classification; Laryngectomy/Adverse Effects; Larynx, Artificial/Adverse Effects, Classification; Prosthesis Failure; Treatment Outcome. A total of 394,308 articles were identified in concept 3. The final MEDLINE search identified 303 articles by cross-referencing the 3 conceptual reference groups for common articles. The bibliographies of relevant articles were hand-searched to identify additional manuscripts. Hand-searching identified 7 additional articles for a total of 310. [4]

Selection Criteria and Data Collection
The abstracts of 310 peer-reviewed journal articles identified by electronic and hand searches were screened. Articles were excluded after screening according to the following exclusion criteria: (1) single case report study design, (2) review article, (3) non-English publication, or (4) no discussion of complications, failures, enlarged puncture, or prosthetic leakage within the abstract. The full-text of 54 articles was reviewed for the following data points: number of patients studied, number of VP replacements, study design, study setting, length of follow-up, proportion of primary and secondary TEP, receipt of pre- or postoperative radiotherapy, sex, age, case definition (eg, enlarged fistula, leakage around the VP), rate of enlarged TEP and/or leakage around the VP, rate of pneumonia, rate of dislodgement/aspiration of VP, potential risk factors (eg, timing of TEP, radiotherapy, flap reconstruction, diabetes, smoking, hypothyroidism, malnutrition, prosthetic diameter), type of VPs used (brand, diameter, indwelling vs non-indwelling), and conservative management techniques for enlarged TEP. Conservative management was defined as any surgical or nonsurgical intervention used to eliminate leakage around the VP but still preserve functional TE voice. These included temporary removal or modification of the prosthesis, TEP-site injection, TEP-site cautery, and purse-string closure. Complete closure of the TEP site was not considered a conservative management technique and was excluded from the analysis of conservative management. A complete listing of conservative methods is provided in Table 1. [5]

Methodologic Reporting
Consensus guidelines for methodologic reporting in observational studies were established by the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement initiative in 2004.8 [8] The STROBE statement outlines 9 items that should be transparently reported in the methods section of observational research articles to assess the external validity, strengths, and weaknesses of observational findings. The reporting of these 9 methodologic items was recorded for all studies included in this review: (1) study design, (2) study setting, (3) participants, (4) variables, (5) data sources/measurement, (6) bias, (7) study size, (8) quantitative variables, and (9) statistical methods.[9]
Statistical Methods
A meta-analysis was performed to estimate the rate of enlarged puncture/leakage around the VP after total laryngectomy with TEP. A summary risk estimate was calculated using the random-effects model to account for underlying sources of variation between studies beyond that of random error. [10] Meta-analysis results are displayed in a Forest Plot (Figure 1). Results from both prospective and retrospective cohorts were included in the meta-analysis model due to the similarity of observational study designs. The nonparametric Wilcoxon Rank Sum test was used to compare the proportion of patients with enlarged puncture and/or leakage around the VP in risk stratifications. Additional results are presented in descriptive format. Statistical analyses were performed using the STATA data analysis statistical software, version 10.0 (StataCorp, College Station, TX). [11]
Results:
Rate of Enlarged Tracheoesophageal Puncture
Twenty-three studies reported rates of enlarged TEP and/or leakage around the VP T2 (Table 2). Twenty studies reported rates of enlarged TEP and/or leakage around the prosthesis per patient, and 2 by the total number of times the VP was replaced. One study reported rates both by patients and by the number of VP replacements. Overall, an enlarged TEP/leakage around the VP was reported in 1% to 29% of patients (n = 21) and in 3% to 11% of VP replacements (n = 3). The description of the problem varied across studies and can be conceptualized in 2 categories: (1) studies that described leakage around the TEP attributed to an enlarged puncture, or (2) studies that reported leakage around the VP without clearly attributing this occurrence to an enlarged TEP. Thirteen studies that clearly attributed leakage around the VP to an enlarged TEP reported rates of enlarged puncture between 1% and 29% of patients and 3% of VP replacements. In contrast, 10 studies did not clearly attribute leakage around the prosthesis to an enlarged fistula; these studies reported rates of leakage around the VP between 2% and 13% of patients and 7% to 11% of VP replacements. [12]

Summary risk estimate was calculated based on 19 studies; 2 studies that solely reported enlarged TEP per number of VP replacements were excluded from the meta-analysis. Two overlapping cohorts were identified in this review1,4,9,10; the latter publications4,10 from these cohorts were included in the meta-analysis. The test of homogeneity revealed significant differences in risk of enlarged TEP/leakage around the VP between studies (Q-test; p < .0001). Therefore, the summary risk estimate was calculated using a random-effects model; [13] the summary risk estimate for enlarged TEP/leakage around the VP was 7.2% (95% CI, 4.8% to 9.6%). Risk estimates and 95% CIs for each study and the summary estimate are illustrated in Figure 1. Ten studies reported the effectiveness of conservative treatments (excluding complete surgical closure of the TEP) for leakage around the VP (Table 3). Outcomes were highly variable; however, none of the conservative treatments reportedly worsened the problem. The assessment methods, outcome measures, and length of follow-up varied substantially across studies. Ten additional studies reported the use of conservative treatment methods including placing an anterior collar, downsizing the TEP with catheter placement, collagen injection, and thickening liquids, but did not describe the effectiveness of these treatments. Complete surgical closure of the TEP site was reported in 14% to 50% of cases in the cohorts we reviewed, and most reported surgical closure in less than 20% of cases.1, 4, 6, 9, 10, 21, 27 No comparative prospective trials were identified Results of conservative treatments for enlarged TEP/leakage around the voice prosthesis (n = 10)* Methodologic Reporting Methodologic reporting was assessed based on the STROBE statement guidelines for observational studies.8 Methodologic reporting was incomplete (at least 1 item was not reported) in all studies, and at least 2 methodologic items were not reported in 96% (22 of 23) of the studies. Specifically, the majority of publications did not report length and method of follow-up (65%), diagnostic criteria for enlarged TEP/leakage around the prosthesis (78%), methods for assessing enlarged TEP (61%), exclusion criteria (78%), and efforts to address potential biases in the study (91%). Discussion: Enlarged TEP is clinically recognized as a significant complication of TE voice restoration; yet the literature provides no consensus regarding the frequency of its occurrence, risk factors, or management. Studies included in this review identified enlarged TEP or leakage around the VP in 1% to 29% of the patients studied. Small sample sizes yielding imprecise estimates along with methodologic differences between studies likely contributed to the wide range of results. Our meta-analysis found a summary risk estimate of 7.2% (95% CI, 4.8% to 9.6%) for enlarged TEP/leakage around the VP. The 95% CI indicates that the risk of an enlarged TEP may be as low as 5% or as high as 10%, suggesting a relatively low overall risk of this complication after TEP. Risk of enlarged puncture is likely elevated in certain groups of patients; unfortunately, incomplete reporting precluded our ability to assess potential risk factors using meta-regression techniques. We considered differences in the rate of enlarged puncture/leakage around the VP by geographic region and decade of publication. Substantial differences were not observed between European and North American cohorts. Interestingly, the median rate of enlarged puncture/leakage around the VP did fluctuate by decade of publication. The differences observed may be due in part to the small number of studies published in each decade; however, higher median rates reported in the 1980s and 2000s may also reflect a learning curve in the development period of alaryngeal voice restoration (1980s) and more recently the use of TEP in medically complex salvage laryngectomy cases after chemoradiation failure (2000s). In contrast, the lower median rate observed in the 1990s may be reflective of fewer complications seen with routine application of this procedure in standard, frontline laryngectomy.[19] Another objective of this systematic review was to estimate the risk of pneumonia in patients with enlarged TEP. Aspiration related to enlarged puncture is a potentially life-threatening complication, as evidenced by 1 study that reported death in a patient who developed severe aspiration pneumonia after progressive enlargement of the TEP.12 Few authors3, 11, 12, however, acknowledged a relationship between leakage around the VP/enlarged TEP and pneumonia. Enlargement of the TEP should also increase the likelihood of spontaneous dislodgement of the VP. Dislodgement of the prosthesis poses risk for severe aspiration through the open, unstented TE tract and consequently increases the potential for aspiration pneumonia. In addition, frequent dislodgement of the VP increases the chance of aspiration of the prosthesis. None of the studies included in this review, however, reported the frequency of prosthetic dislodgement or aspiration of the VP in patients with enlarged TEP. This review also sought to summarize the effect of potential risk factors for enlarged TEP. The risk of enlarged TEP may increase over time as a late complication of treatment. Four studies reviewed1, 6, 21, 26 documented TEP enlargement between 1 and 115 months post-TEP with mean time to enlargement between 20 and 40 months. Tissue damage associated with radiation therapy may contribute to the development of enlarged TEP and often manifests months or years after treatment has ended. Thus, the length of follow-up becomes a critical consideration when estimating the risk of this complication, but was not specified in more than half of the studies reviewed. In addition, none of the studies included in this review statistically analyzed the effect of radiation therapy on enlarged TEP nor was radiation history reported consistently across studies, which precluded our assessment of this risk factor by meta-regression methods or subgroup analysis. The use of a large diameter VP has gained recent interest as another potential risk factor for enlarged TEP.3, 28, 29 Our subgroup analysis did not identify a statistically significant difference in the risk of enlarged TEP/leakage around the VP based on prosthetic diameter in studies that exclusively used a single diameter VP; however, there was a tendency toward higher rates in cohorts that used a 22-French or larger diameter prosthesis. Alternatively, 2 studies compared leakage patterns between prostheses of different diameters. Acton et al3 concluded that leakage around the VP could be minimized by avoiding large diameter (20-French) prostheses based on their finding that 76% of cases of leakage around the VP occurred in patients wearing a 20-French VP. However, the majority (61%) of all prosthetic changes in their sample occurred using a 20-French VP. Thus, it is unclear whether their findings reflect an unequal sample distribution of prosthetic diameters as they did not statistically analyze this association. We calculated a nonsignificant elevated relative risk (RR, 2.05; 95% CI, 0.78–5.36; p = .13) based on their data. In addition, Issing et al29 reported salivary leakage exclusively in patients who wore a 22.5-French diameter VP compared to no cases of leakage in patients who wore a 16.5-French prosthesis. It is difficult to interpret the relevance of these findings to the risk of enlarged TEP as the case definition for salivary leakage was unclear and reported data were inconsistent. Therefore, it cannot be concluded based on current evidence that a large diameter VP increases the risk of enlarged TEP. Nevertheless, current data do not exclude the possibility of an association, and prosthetic diameter may be an important consideration, particularly in the management of patients who are at greater risk of complications after TEP. CONCLUSION Our meta-analysis suggests that the overall risk of enlarged puncture after total laryngectomy with TEP is relatively low (<10%); however, this complication presents a significant challenge for patients and clinicians to manage. We identified a number of conservative treatment methods that have been proposed to eliminate leakage around the prosthesis while maintaining functional TE voice; however, an effective long-term solution has not yet been reported. Current data suggest that, in most cases, conservative management techniques provide only transient relief of this complication. Incomplete reporting and methodologic discrepancies limit the ability to compare conservative treatment methods further or develop an evidenced-based algorithm for management. In addition, this review did not find clear evidence for any single risk factor for enlarged TEP. Our findings suggest that the role of prosthetic diameter remains controversial, and no study provided quantifiable evidence for the association between enlarged puncture and the effects of radiotherapy. It should be emphasized that the development of an enlarged puncture is a multifactorial event. Further investigation is needed to identify individual risk factors and multivariable interactions to achieve prevention of the enlarged TEP. Directions for future research should also include correlation of enlarged puncture with pneumonia, and prospective comparative assessments of conservative treatment methods. We are currently reviewing our experience with enlarged puncture guided by the findings of this systematic review and meta-analysis.
REFERENCES
1. Singer MI, Blom ED. An endoscopic technique for restoration of voice after laryngectomy. Ann Otol Rhinol Laryngol. 1980;89(6 Pt 1):529–533. [PubMed]
2. Lewin JS, Hutcheson KA. Head and Neck Cancer A Multidisciplinary Approach. Philadelphia: Lippincott Williams & Wilkins; 2009. General principles of rehabilitation of speech, voice, and swallowing function after treatment of head and neck cancer; pp. 168–177.
3. Acton LM, Ross DA, Sasaki CT, Leder SB. Investigation of tracheoesophageal voice prosthesis leakage patterns: patient’s self-report versus clinician’s confirmation. Head Neck. 2008;30:618–621. [PubMed]
4. Op de Coul BM, Hilgers FJ, Balm AJ, Tan IB, van den Hoogen FJ, van Tinteren H. A decade of postlaryngectomy vocal rehabilitation in 318 patients: a single institution’s experience with consistent application of Provox indwelling voice prostheses. Arch Otolaryngol Head Neck Surg. 2000;126:1320–1328. [PubMed]
5. Izdebski K, Reed CG, Ross JC, Hilsinger RL., Jr Problems with tracheoesophageal fistula voice restoration in totally laryngectomized patients. A review of 95 cases. Arch Otolaryngol Head Neck Surg. 1994;120:840–845. [PubMed]
6. Jacobs K, Delaere PR, Vander Poorten VL. Submucosal purse-string suture as a treatment of leakage around the indwelling voice prosthesis. Head Neck. 2008;30:485–491. [PubMed]
7. Kress P, Schäfer P, Schwerdtfeger FP. The custom-fit voice prosthesis, for treatment of periprothetic leakage after tracheoesophageal voice restoration. Laryngorhinootologie. 2006;85:496–500. [Article in German] [PubMed]
8. von Elm E, Altman DG, Egger M, et al. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. J Clin Epidemiol. 2008;61:344–349. [PubMed]
9. Hilgers FJ, Balm AJ. Long-term results of vocal rehabilitation after total laryngectomy with the low-resistance, indwelling Provox voice prosthesis system. Clin Otolaryngol Allied Sci. 1993;18:517–523. [PubMed]
10. Singer MI, Blom ED, Hamaker RC. Further experience with voice restoration after total laryngectomy. Ann Otol Rhinol Laryngol. 1981;90(5 Pt 1):498–502. [PubMed]
11. Andrews JC, Mickel RA, Hanson DG, Monahan GP, Ward PH. Major complications following tracheoesophageal puncture for voice rehabilitation. Laryngoscope. 1987;97:562–567. [PubMed]
12. Cornu AS, Vlantis AC, Elliott H, Gregor RT. Voice rehabilitation after laryngectomy with the Provox voice prosthesis in South Africa. J Laryngol Otol. 2003;117:56–59. [PubMed]
13. Ferrer Ramírez MJ, Guallart Doménech F, Brotons Durbán S, Carrasco Llatas M, Estellés Ferriol E, López Martínez R. Surgical voice restoration after total laryngectomy: long-term results. Eur Arch Otorhinolaryngol. 2001;258:463–466. [PubMed]
14. Silverman AH, Black MJ. Efficacy of primary tracheoesophageal puncture in laryngectomy rehabilitation. J Otolaryngol. 1994;23:370–377. [PubMed]
15. Mehta AR, Sarkar S, Mehta SA, Bachher GK. The Indian experience with immediate tracheoesophageal puncture for voice restoration. Eur Arch Otorhinolaryngol. 1995;252:209–214. [PubMed]
16. Silver FM, Gluckman JL, Donegan JO. Operative complications of tracheoesophageal puncture. Laryngoscope. 1985;95:1360–1362. [PubMed]
17. Juarbe C, Shemen L, Eberle R, Klatsky I, Fox M. Primary tracheoesophageal puncture for voice restoration. Am J Surg. 1986;152:464–466. [PubMed]
18. Fukutake T, Yamashita T. Speech rehabilitation and complications of primary tracheoesophageal puncture. Acta Otolaryngol Suppl. 1993;500:117–120. [PubMed]
19. de Carpentier JP, Ryder WD, Saeed SR, Woolford TJ. Survival times of Provox valves. J Laryngol Otol. 1996;110:37–42. [PubMed]
20. Gerwin JM, Culton GL. Prosthetic voice restoration with the tracheostomal valve: a clinical experience. Am J Otolaryngol. 1993;14:432–439. [PubMed]

BLINDED VERSION
Introduction:
The gold standard for voice restoration after total laryngectomy is tracheoesophageal puncture (TEP). The TEP is a small surgically created fistula in the tracheoeosphageal (TE) wall that may be created at the time of the total laryngectomy (primary TEP) or later after the patient has healed from surgery (secondary TEP). A one-way valved silicone voice prosthesis (VP) is placed into the TEP. The prosthetic valve opens to allow pulmonary air into the vocal tract for vibratory sound production when the tracheostoma is occluded, but remains closed to prevent aspiration of foods/liquids during swallowing.1,2 [1]
One of the most difficult complications to manage after TEP is enlargement of the TE fistula that results in aspiration of saliva, liquid, and/or food around the VP into the trachea. Tissue changes associated with radiation, malnourishment, diabetes, smoking, and hypothyroidism may reduce elasticity and integrity of the TEP and have been implicated as potential risk factors for enlarged puncture.3–6 Development of an enlarged TEP has also been associated with acute infection or tumor recurrence.3,7 However, the actual contribution of these potential risk factors is unclear.
An enlarged TEP intuitively increases the risk of pneumonia and respiratory complications due to frequent aspiration around the VP. Reduced tissue elasticity also increases the likelihood of spontaneous dislodgement of the VP and consequently the potential for aspiration of the prosthesis. Various treatments, including surgical closure of the TEP, have been proposed to mitigate the ill-effects of an enlarged TEP. Although surgical closure eliminates problems associated with leakage around the prosthesis, closure of the TEP prevents TE voice production, thus negatively impacting quality of life. Because of this, conservative methods, either surgical or nonsurgical, that aim to eliminate leakage around the VP while preserving functional TE voice, either surgical or nonsurgical but excluding complete TEP closure, are of particular interest. Although a variety of conservative treatments have been proposed, there are no clear guidelines for the conservative management of this complication.[2]
A better understanding of factors associated with enlarged TEP will lead to more uniform assessment and management of this complication, and may guide preventive efforts..[3]
Materials and Methods:
Search Methods:
The search for this systematic review was conducted from May through July2008. The primary search was conducted using the electronic MEDLINE database (data source: OVID). The search was limited to human subject research in peer-reviewed journal articles published between 1978 and June (week 1) 2008. Medical subject heading (MeSH) terms were used to identify articles pertaining to 3 conceptual groups of references: (1) total laryngectomy, (2) TEP/alaryngeal voice restoration, and (3) complications. Within concept 1 (“total laryngectomy”), the following MeSH terms were ‘exploded’ to include all subject headings under the term: Laryngectomy, Laryngeal Neoplasms/Surgery. A total of 10,417 articles were identified in concept 1. These terminologies also identified extended procedures that included pharyngeal resection and use of flap reconstructions. Within concept 2 (“TEP/alaryngeal voice restoration”), the following MeSH terms and subheadings were exploded: Larynx, Artificial; Speech, Alaryngeal; Tracheoesophageal Fistula/Rehabilitation, Surgery; Laryngeal Neoplasms/Rehabilitation; Prosthesis Implantation/Rehabilitation, Methods; Laryngectomy/Rehabilitation. A total of 15,178 articles were identified in concept 2. Within concept (“complications”), the following MeSH terms and subheadings were exploded: Punctures/Adverse Effects, Classification, Complications; Prostheses and Implants/Adverse Effects, Classification; Laryngectomy/Adverse Effects; Larynx, Artificial/Adverse Effects, Classification; Prosthesis Failure; Treatment Outcome. A total of 394,308 articles were identified in concept 3. The final MEDLINE search identified 303 articles by cross-referencing the 3 conceptual reference groups for common articles. The bibliographies of relevant articles were hand-searched to identify additional manuscripts. Hand-searching identified 7 additional articles for a total of 310. [4]

Selection Criteria and Data Collection
The abstracts of 310 peer-reviewed journal articles identified by electronic and hand searches were screened. Articles were excluded after screening according to the following exclusion criteria: (1) single case report study design, (2) review article, (3) non-English publication, or (4) no discussion of complications, failures, enlarged puncture, or prosthetic leakage within the abstract. The full-text of 54 articles was reviewed for the following data points: number of patients studied, number of VP replacements, study design, study setting, length of follow-up, proportion of primary and secondary TEP, receipt of pre- or postoperative radiotherapy, sex, age, case definition (eg, enlarged fistula, leakage around the VP), rate of enlarged TEP and/or leakage around the VP, rate of pneumonia, rate of dislodgement/aspiration of VP, potential risk factors (eg, timing of TEP, radiotherapy, flap reconstruction, diabetes, smoking, hypothyroidism, malnutrition, prosthetic diameter), type of VPs used (brand, diameter, indwelling vs non-indwelling), and conservative management techniques for enlarged TEP. Conservative management was defined as any surgical or nonsurgical intervention used to eliminate leakage around the VP but still preserve functional TE voice. These included temporary removal or modification of the prosthesis, TEP-site injection, TEP-site cautery, and purse-string closure. Complete closure of the TEP site was not considered a conservative management technique and was excluded from the analysis of conservative management. A complete listing of conservative methods is provided in Table 1. [5]

Methodologic Reporting
Consensus guidelines for methodologic reporting in observational studies were established by the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement initiative in 2004.8 [8] The STROBE statement outlines 9 items that should be transparently reported in the methods section of observational research articles to assess the external validity, strengths, and weaknesses of observational findings. The reporting of these 9 methodologic items was recorded for all studies included in this review: (1) study design, (2) study setting, (3) participants, (4) variables, (5) data sources/measurement, (6) bias, (7) study size, (8) quantitative variables, and (9) statistical methods.[9]
Statistical Methods
A meta-analysis was performed to estimate the rate of enlarged puncture/leakage around the VP after total laryngectomy with TEP. A summary risk estimate was calculated using the random-effects model to account for underlying sources of variation between studies beyond that of random error. [10] Meta-analysis results are displayed in a Forest Plot (Figure 1). Results from both prospective and retrospective cohorts were included in the meta-analysis model due to the similarity of observational study designs. The nonparametric Wilcoxon Rank Sum test was used to compare the proportion of patients with enlarged puncture and/or leakage around the VP in risk stratifications. Additional results are presented in descriptive format. Statistical analyses were performed using the STATA data analysis statistical software, version 10.0 (StataCorp, College Station, TX). [11]
Results:
Rate of Enlarged Tracheoesophageal Puncture
Twenty-three studies reported rates of enlarged TEP and/or leakage around the VP T2 (Table 2). Twenty studies reported rates of enlarged TEP and/or leakage around the prosthesis per patient, and 2 by the total number of times the VP was replaced. One study reported rates both by patients and by the number of VP replacements. Overall, an enlarged TEP/leakage around the VP was reported in 1% to 29% of patients (n = 21) and in 3% to 11% of VP replacements (n = 3). The description of the problem varied across studies and can be conceptualized in 2 categories: (1) studies that described leakage around the TEP attributed to an enlarged puncture, or (2) studies that reported leakage around the VP without clearly attributing this occurrence to an enlarged TEP. Thirteen studies that clearly attributed leakage around the VP to an enlarged TEP reported rates of enlarged puncture between 1% and 29% of patients and 3% of VP replacements. In contrast, 10 studies did not clearly attribute leakage around the prosthesis to an enlarged fistula; these studies reported rates of leakage around the VP between 2% and 13% of patients and 7% to 11% of VP replacements. [12]

Summary risk estimate was calculated based on 19 studies; 2 studies that solely reported enlarged TEP per number of VP replacements were excluded from the meta-analysis. Two overlapping cohorts were identified in this review1,4,9,10; the latter publications4,10 from these cohorts were included in the meta-analysis. The test of homogeneity revealed significant differences in risk of enlarged TEP/leakage around the VP between studies (Q-test; p < .0001). Therefore, the summary risk estimate was calculated using a random-effects model; [13] the summary risk estimate for enlarged TEP/leakage around the VP was 7.2% (95% CI, 4.8% to 9.6%). Risk estimates and 95% CIs for each study and the summary estimate are illustrated in Figure 1. Ten studies reported the effectiveness of conservative treatments (excluding complete surgical closure of the TEP) for leakage around the VP (Table 3). Outcomes were highly variable; however, none of the conservative treatments reportedly worsened the problem. The assessment methods, outcome measures, and length of follow-up varied substantially across studies. Ten additional studies reported the use of conservative treatment methods including placing an anterior collar, downsizing the TEP with catheter placement, collagen injection, and thickening liquids, but did not describe the effectiveness of these treatments. Complete surgical closure of the TEP site was reported in 14% to 50% of cases in the cohorts we reviewed, and most reported surgical closure in less than 20% of cases.1, 4, 6, 9, 10, 21, 27 No comparative prospective trials were identified Results of conservative treatments for enlarged TEP/leakage around the voice prosthesis (n = 10)* Methodologic Reporting Methodologic reporting was assessed based on the STROBE statement guidelines for observational studies.8 Methodologic reporting was incomplete (at least 1 item was not reported) in all studies, and at least 2 methodologic items were not reported in 96% (22 of 23) of the studies. Specifically, the majority of publications did not report length and method of follow-up (65%), diagnostic criteria for enlarged TEP/leakage around the prosthesis (78%), methods for assessing enlarged TEP (61%), exclusion criteria (78%), and efforts to address potential biases in the study (91%). Discussion: Enlarged TEP is clinically recognized as a significant complication of TE voice restoration; yet the literature provides no consensus regarding the frequency of its occurrence, risk factors, or management. Studies included in this review identified enlarged TEP or leakage around the VP in 1% to 29% of the patients studied. Small sample sizes yielding imprecise estimates along with methodologic differences between studies likely contributed to the wide range of results. Our meta-analysis found a summary risk estimate of 7.2% (95% CI, 4.8% to 9.6%) for enlarged TEP/leakage around the VP. The 95% CI indicates that the risk of an enlarged TEP may be as low as 5% or as high as 10%, suggesting a relatively low overall risk of this complication after TEP. Risk of enlarged puncture is likely elevated in certain groups of patients; unfortunately, incomplete reporting precluded our ability to assess potential risk factors using meta-regression techniques. We considered differences in the rate of enlarged puncture/leakage around the VP by geographic region and decade of publication. Substantial differences were not observed between European and North American cohorts. Interestingly, the median rate of enlarged puncture/leakage around the VP did fluctuate by decade of publication. The differences observed may be due in part to the small number of studies published in each decade; however, higher median rates reported in the 1980s and 2000s may also reflect a learning curve in the development period of alaryngeal voice restoration (1980s) and more recently the use of TEP in medically complex salvage laryngectomy cases after chemoradiation failure (2000s). In contrast, the lower median rate observed in the 1990s may be reflective of fewer complications seen with routine application of this procedure in standard, frontline laryngectomy.[19] Another objective of this systematic review was to estimate the risk of pneumonia in patients with enlarged TEP. Aspiration related to enlarged puncture is a potentially life-threatening complication, as evidenced by 1 study that reported death in a patient who developed severe aspiration pneumonia after progressive enlargement of the TEP.12 Few authors3, 11, 12, however, acknowledged a relationship between leakage around the VP/enlarged TEP and pneumonia. Enlargement of the TEP should also increase the likelihood of spontaneous dislodgement of the VP. Dislodgement of the prosthesis poses risk for severe aspiration through the open, unstented TE tract and consequently increases the potential for aspiration pneumonia. In addition, frequent dislodgement of the VP increases the chance of aspiration of the prosthesis. None of the studies included in this review, however, reported the frequency of prosthetic dislodgement or aspiration of the VP in patients with enlarged TEP. This review also sought to summarize the effect of potential risk factors for enlarged TEP. The risk of enlarged TEP may increase over time as a late complication of treatment. Four studies reviewed1, 6, 21, 26 documented TEP enlargement between 1 and 115 months post-TEP with mean time to enlargement between 20 and 40 months. Tissue damage associated with radiation therapy may contribute to the development of enlarged TEP and often manifests months or years after treatment has ended. Thus, the length of follow-up becomes a critical consideration when estimating the risk of this complication, but was not specified in more than half of the studies reviewed. In addition, none of the studies included in this review statistically analyzed the effect of radiation therapy on enlarged TEP nor was radiation history reported consistently across studies, which precluded our assessment of this risk factor by meta-regression methods or subgroup analysis. The use of a large diameter VP has gained recent interest as another potential risk factor for enlarged TEP.3, 28, 29 Our subgroup analysis did not identify a statistically significant difference in the risk of enlarged TEP/leakage around the VP based on prosthetic diameter in studies that exclusively used a single diameter VP; however, there was a tendency toward higher rates in cohorts that used a 22-French or larger diameter prosthesis. Alternatively, 2 studies compared leakage patterns between prostheses of different diameters. Acton et al3 concluded that leakage around the VP could be minimized by avoiding large diameter (20-French) prostheses based on their finding that 76% of cases of leakage around the VP occurred in patients wearing a 20-French VP. However, the majority (61%) of all prosthetic changes in their sample occurred using a 20-French VP. Thus, it is unclear whether their findings reflect an unequal sample distribution of prosthetic diameters as they did not statistically analyze this association. We calculated a nonsignificant elevated relative risk (RR, 2.05; 95% CI, 0.78–5.36; p = .13) based on their data. In addition, Issing et al29 reported salivary leakage exclusively in patients who wore a 22.5-French diameter VP compared to no cases of leakage in patients who wore a 16.5-French prosthesis. It is difficult to interpret the relevance of these findings to the risk of enlarged TEP as the case definition for salivary leakage was unclear and reported data were inconsistent. Therefore, it cannot be concluded based on current evidence that a large diameter VP increases the risk of enlarged TEP. Nevertheless, current data do not exclude the possibility of an association, and prosthetic diameter may be an important consideration, particularly in the management of patients who are at greater risk of complications after TEP. CONCLUSION
Our meta-analysis suggests that the overall risk of enlarged puncture after total laryngectomy with TEP is relatively low (<10%); however, this complication presents a significant challenge for patients and clinicians to manage. We identified a number of conservative treatment methods that have been proposed to eliminate leakage around the prosthesis while maintaining functional TE voice; however, an effective long-term solution has not yet been reported. Current data suggest that, in most cases, conservative management techniques provide only transient relief of this complication. Incomplete reporting and methodologic discrepancies limit the ability to compare conservative treatment methods further or develop an evidenced-based algorithm for management. In addition, this review did not find clear evidence for any single risk factor for enlarged TEP. Our findings suggest that the role of prosthetic diameter remains controversial, and no study provided quantifiable evidence for the association between enlarged puncture and the effects of radiotherapy. It should be emphasized that the development of an enlarged puncture is a multifactorial event. Further investigation is needed to identify individual risk factors and multivariable interactions to achieve prevention of the enlarged TEP. Directions for future research should also include correlation of enlarged puncture with pneumonia, and prospective comparative assessments of conservative treatment methods. We are currently reviewing our experience with enlarged puncture guided by the findings of this systematic review and meta-analysis.