P-121 Azoospermia: are there neonatal differences regarding the source of sperm for ICSI?

Study question

In couples with azoospermia undergoing intracytoplasmic sperm injection (ICSI), are neonatal outcomes different depending on sperm origin (epididymal-PESA, testicular-TESA or donor sperm)?

Summary answer

Newborns from PESA or TESA had similar neonatal outcomes. Comparing to donor cases, PESA/TESA cycles didn’t present increased levels of malformation or stillbirth.

What is known already

Since the introduction of ICSI and the demonstration that the spermatozoa derived either from the epididymis or the testis were capable of normal fertilization and pregnancy, it was possible for azoospermic men to father their own children. However, it raised concerns that the quality of spermatozoa in terms of DNA damage or maturation when collected from non-ejaculated semen could differ from that collected from ejaculated and whether sperm of different origins will affect the neonatal outcome and safety of ICSI.

Study design, size, duration

Retrospective cohort study performed at a reproductive medicine center, using data from 359 deliveries from 945 cycles of ICSI of couples with infertility due to azoospermia, performed between 1995 and 2021. Data were collected from electronic records.

Participants/materials, setting, methods

A total of 359 deliveries were divided in 3 groups, according to the sperm source: PESA (n = 138), TESA (n = 139) and DONOR (n = 82). A total of 402 newborns were evaluated: PESA (n = 162); TESA (n = 156); DONOR (n = 84). Neonatal outcomes and congenital malformations were analyzed for singletons, twins and triplets separately. Statistical analysis: Anova, chi-square and Fischer test, considering p < 0.05.

Main results and the role of chance

Comparing the 3 groups (PESA, TESA, and donor sperm), the following results were found: The mean birth weight (BW), length and Apgar score > 7 for singletons and twins did not differ between groups; neither did prematurity or extreme prematurity. According to birth percentile, there was a lower rate of small for gestational age (SGA) newborn in the epididymal group (PESA, 1.5% vs. TESA, 8.5% vs. sperm donor, 5.5%, p = 0.004). Also, in 158 twin births, the number of newborns with low birth weight (<2500g) was significantly smaller in the epididymal group (PESA, 32.9% vs. TESA, 62.5%; donor sperm, 73.1%, p = 0.001). There were three stillbirths in triplets (PESA group). We also found six cases of neonatal mortality (one in singleton pregnancy in TESA group, 3 in twins (two in PESA group and one donor sperm group), and two in triplets (one in TESA and one in PESA groups). The total number of congenital malformations was 8 (2.48%) (PESA n = 1, 0.62%; TESA, n = 2, 1.28%, and donor sperm, n = 5, 5.95%, p = 0.02).

Limitations, reasons for caution

The possibility of incomplete medical records is an important limitation to be considered in retrospective studies. Larger studies are important to better assess the risk of malformation in this population.

Wider implications of the findings

In this study, there were no differences on neonatal outcomes regarding the source of sperm used for ICSI, with PESA, TESA and donor groups, as well as congenital malformation. It showed equally safe options with testis, epididymal or ejaculated sperm for azoospermia treatments.

Trial registration number

not applicable

Electromyography of the posterior cricoarytenoid muscles: a consensus guideline

PURPOSE

Since the introduction of transcutaneous-transcricoidal needle approaches, electromyography (EMG) of the posterior cricoarytenoid muscle (PCA) became easier to perform and teach. Among the Neurolaryngology working group of the European Laryngological Society, several centers have adopted PCA EMG as part of their routine EMG workup in vocal fold immobility collectively gathering long-term experience. The purpose is to give an update and an extension to already existing guidelines on laryngeal EMG with specific regard to PCA EMG.

METHODS

Consensus of all co-authors is based on continuous exchange of ideas and on joint laryngeal EMG workshop experiences over at least 7 years. A Delphi method of consensus development was used, i.e., the manuscript was circulated among the co-authors until full agreement was achieved.

RESULTS

Step-by-step instructions on how to perform and interpret PCA EMG are provided.

CONCLUSIONS

Further research should include the establishment of normal values for PCA and thyroarytenoid muscle (TA) EMG as well as studies on the nature of some unusual activation pattern commonly seen in chronically lesioned PCA.

Crumley's Classification of Laryngeal Synkinesis: A Comparison of Laryngoscopy and Electromyography

OBJECTIVES/HYPOTHESIS

Applying the principles of misdirected nerve regeneration to the larynx, Roger Crumley in 1989 coined the term laryngeal synkinesis (LS) which he later (2000) classified into 4 types (type I - good voice, type II - involuntary twitches and poor voice, type III - adduction during inspiration, type IV - abduction during phonation). Neurophysiological data were not available for all LS patients at that time. The current study was undertaken to utilize and test the Crumley classification for a clinical interrater comparison and, secondly, compare predicted with actual laryngeal electromyography (LEMG) results.

STUDY DESIGN

Descriptive study.

METHODS

Laryngoscopic and LEMG data of patients with unilateral vocal fold paralysis (VFP) of 6 months duration or longer were combined for retrospective evaluation. Forty-five data sets were available for laryngoscopic classification by two local laryngologists and by Roger Crumley. Twenty-three data sets with complete thyroarytenoid (TA) and posterior cricoarytenoid (PCA) - EMG data were used to compare predicted with actual LEMG results.

RESULTS

Local laryngologists were able to classify 24 of 45, Crumley 30 of 45 cases into one of the 4 synkinesis types. There was substantial agreement between examiners (Cohens Kappa 0.66 [P < .001]). Comparison of predicted and actual LEMG data showed only moderate agreement. EMG sykinesis rates were lower in TA than in PCA and highest in Crumley type I cases.

CONCLUSION

The Crumley classification is helpful in describing and understanding synkinesis. It does not always correlate predictably with actual LEMG data. A complete LEMG mapping of all intrinsic muscles may improve understanding of chronic VFP.

LEVEL OF EVIDENCE

4. Laryngoscope, 131:E1605-E1610, 2021.

PCA Atrophy and Synkinesis as the Main Factors for Persistent Vocal Fold Immobility in RLN Paralysis

OBJECTIVES/HYPOTHESIS

An immobile vocal fold due to recurrent laryngeal nerve (RLN) injury usually shows no gross signs of atrophy and lies near the midline. In 1881, Felix Semon proposed that this phenomenon was due to a selective injury of nerve fibers supplying the posterior cricoarytenoid muscle (PCA) and supported this with postmortem proof of selective PCA atrophy. In recent decades, evidence has emerged that the RLN regenerates after injury but does not always result in useful motion of the vocal folds. It has been proposed that this is caused by laryngeal synkinesis. Laryngeal synkinesis describes a random distribution of regenerated nerve fibers to opposing vocal fold muscles. This study was conducted to clarify the relative contribution of these two potential pathomechanisms in our patient population.

STUDY DESIGN

Retrospective case analysis.

METHODS

Retrospective analysis of laryngeal EMG results from cases with RLN paralysis of at least 6 months duration seen at our neurolaryngology clinic.

RESULTS

Out of 118 PCA EMGs, there was not a single normal or near-normal tracing, whilst 33.3% of TA EMGs indicated normal or near normal innervation. PCA EMGs showed signs of persistent high-grade partial denervation (41.5%) as a sign of atrophy, moderate or strong synkinesis (21.2%), or a combination of both (37.3%).

CONCLUSIONS

In chronic RLN paralysis the intrinsic laryngeal muscles are affected to different extents either by atrophy or synkinesis or a combination of both. The PCA is always affected. The lesser damage to TA innervation explains the commonly seen maintenance of vocal fold muscle bulk.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E1244-E1248, 2021.

Inter-rater reliability of seven neurolaryngologists in laryngeal EMG signal interpretation

Purpose

Laryngeal electromyography (LEMG) has been considered as gold standard in diagnostics of vocal fold movement impairment, but is still not commonly implemented in clinical routine. Since the signal interpretation of LEMG signals (LEMGs) is often a subjective and semi-quantitative matter, the goal of this study was to evaluate the inter-rater reliability of neurolaryngologists on LEMGs of volitional muscle activity.

Methods

For this study, 52 representative LEMGs of 371 LEMG datasets were selected from a multicenter registry for a blinded evaluation by 7 experienced members of the neurolaryngology working group of the European Laryngological Society (ELS). For the measurement of the observer agreement between two raters, Cohen’s Kappa statistic was calculated. For the interpretation of agreements of diagnoses among the seven examiners, we used the Fleiss’ Kappa statistic.

Result

When focusing on the categories “no activity”, “single fiber pattern”, and “strongly decreased recruitment pattern”, the inter-rater agreement varied from Cohen’s Kappa values between 0.48 and 0.84, indicating moderate to near-perfect agreement between the rater pairs. Calculating with Fleiss’ Kappa, a value of 0.61 showed good agreement among the seven raters. For the rating categories, the Fleiss’ Kappa value ranged from 0.52 to 0.74, which also showed a good agreement.

Conclusion

A good inter-rater agreement between the participating neurolaryngologists was achieved in the interpretation of LEMGs. More instructional courses should be offered to broadly implement LEMG as a reliable diagnostic tool in evaluating vocal fold movement disorders in clinical routine and to develop future algorithms for therapy and computer-assisted examination.

Laryngeal EMG: Preferential damage of the posterior cricoarytenoid muscle branches especially in iatrogenic recurrent laryngeal nerve lesions

OBJECTIVE

Laryngeal electromyography (LEMG) of the thyroarytenoid (TA) muscle alone may not be sufficient in all patients to characterize or prove a recurrent laryngeal nerve (RLN) lesion in cases of vocal fold immobility. LEMG of the posterior cricoarytenoid (PCA) muscle may provide additional information.

STUDY DESIGN

Retrospective review.

METHOD

Between 2008 and 2016, 339 patients in our laryngeal paralysis clinic were examined by transcutaneous needle TA-LEMG and, if tolerated, by PCA-LEMG. LEMGs were rated and compared according to criteria of the European Laryngological Society. Etiology was categorized as iatrogenic, noniatrogenic, or malignancy related.

RESULTS

A total of 282 out of 339 patients had a partial or complete RLN or vagal nerve lesion: 178 iatrogenic, 74 noniatrogenic, and 30 because of nerve involvement by malignancies. Of paralytic vocal folds, 35.7% had normal or near-normal TA innervation, whereas corresponding PCA traces (if present) were pathologic in 94.6%. Comparing pairs of TA and PCA-LEMGs in paralysis of less than 4 months duration showed a predominance of PCA branch injuries in iatrogenic lesions (71.7 %), while in noniatrogenic lesions this was less pronounced (44.4%). In the few malignancy cases, there was an almost even distribution. Synkinetic reinnervation was earlier in iatrogenic RLN lesions.

CONCLUSION

PCA-LEMG was better in proving an RLN lesion than TA-EMG alone. Our findings suggest etiology-dependent differences in the TA/PCA lesion pattern. To confirm this, larger sample sizes are needed. A preferential damage to PCA innervation in iatrogenic lesions could be relevant for further improvements of intraoperative neuromonitoring.

LEVEL OF EVIDENCE

4. Laryngoscope, 128:1152-1156, 2018.

Laryngeal pacing for bilateral vocal fold paralysis: Voice and respiratory aspects

OBJECTIVE

To evaluate the effects of neurostimulation with the laryngeal pacemaker (LP) system in patients with bilateral vocal fold paralysis (BVFP) in terms of voice quality and respiratory function.

STUDY DESIGN

Feasibility study, first-in-human, single-arm, open-label, prospective, multicenter study with group-sequential design and 6-month follow-up period, as described in details in our previous publication.

METHODS

Nine symptomatic BVFP subjects were unilaterally implanted with the LP system at three study sites in Germany and Austria. Subjective and objective voice function, spirometric parameters other than peak expiratory/inspiratory flow (PEF/PIF), and PEF-meter self-assessment were evaluated pre- and 6 months postimplantation.

RESULTS

In general, the LP system did not considerably change the voice quality of the implanted patients. Only the sound pressure level range improved significantly 6 months postimplantation (P = 0.018). The LP system implantation did not affect the glottal closure configuration, the duration of the closed phase, and the mucosal wave of the implanted side. The evaluated spirometric parameters were not significantly affected by laryngeal pacing, whereas PEF meter self-assessment showed a stable and significant (P = 0.028) improvement of the PEF within a week upon activation of the LP system.

CONCLUSION

Neurostimulation with the LP system results in an immediate and stable PEF improvement, without negative effects on the voice quality. The PEF meter self-assessment confirmed the spirometry results of the PEF. The stimulated abduction did not affect the glottal closure during phonation. These results should be confirmed in larger and more homogenous patient cohorts.

LEVEL OF EVIDENCE

2b Laryngoscope, 127:1838-1844, 2017.

Laryngeal pacing via an implantable stimulator for the rehabilitation of subjects suffering from bilateral vocal fold paralysis: A prospective first-in-human study

OBJECTIVES/HYPOTHESIS

To evaluate the performance and safety of the newly developed Laryngeal Pacemaker System (LP System) for the treatment of bilateral vocal fold paralysis (BVFP).

STUDY DESIGN

Feasibility, first-in-human, single-arm, open-label, prospective, multicenter study with a group sequential design and a 6-month follow-up period.

METHODS

Nine symptomatic BVFP subjects were implanted unilaterally with the LP System. Pre- and 6-month postimplantation evaluations consisted of the 6-Minute Walk Test (6MWT), the Peak Expiratory and Inspiratory Flow (PEF and PIF) evaluation, the PEF meter analysis, the 36-Item Short Form Health Survey (SF-36), the Glasgow Benefit Inventory (GBI), the 12-Item Voice Handicap Index (VHI-12), and the Fiberoptic Endoscopic Evaluation of Swallowing. The safety profile of the LP System was continuously monitored.

RESULTS

The LP System implantation was achieved in 8/9 cases. Seven of the nine subjects completed the study. Absolute PEF and PIF values improved significantly 6 months postimplantation (P < .05). 6MWT results showed a non-statistically significant improvement (P = .09). The mental component of the SF-36 showed a significant improvement (P = .043), whereas the other SF-36 components, the GBI, and the VHI-12 results did not changed significantly. The LP System did not affect the voice and swallowing quality and maintained a reliable safety profile for the duration of the study.

CONCLUSIONS

This feasibility study showed that the LP System has the potential to become an effective and safe treatment for BVFP subjects without compromising the patients' voice.

LEVEL OF EVIDENCE

2b Laryngoscope, 126:1810-1816, 2016.

Pre-clinical evaluation of a minimally invasive laryngeal pacemaker system in mini-pig

Microlaryngoscopic enlargement techniques have been the standard treatment for bilateral vocal fold paralysis (BVFP) for decades. Laryngeal pacing is a promising alternative treatment based on the electrostimulation of the posterior cricoarytenoid (PCA) muscle. This paper reports on the results of a pre-clinical study aiming to evaluate this method. Eight Göttingen mini-pigs were implanted with a laryngeal pacemaker (LP) implant prototype and with two LP electrodes, one in each PCA muscle. The 6-week follow-up included endoscopic stimulation controls in general anaesthesia and radiographic controls of electrode integrity and position stability. Stimulation parameters for optimal glottal opening were evaluated via videolaryngoscopy. Histopathology was performed upon conclusion of the study. 7/8 (87.5 %) animals were successfully implanted with the LP implant prototype and two LP electrodes. In general, stimulation was effectively delivered and correlated with the expected PCA muscle activation. 2/14 (14.3 %) electrodes dislocated and 1/14 (7.1 %) electrode tip broke. The LP system used in this experiment to induce vocal fold abduction by means of selective functional electrical stimulation of the PCA showed promising results. It may be a valid alternative to the current golden standard for BVFP treatment. Clinical studies are needed to confirm the medical relevance of the LP.

Cutting edge: human gamma delta T cells are activated by intermediates of the 2-C-methyl-D-erythritol 4-phosphate pathway of isoprenoid biosynthesis

Activation of V gamma 9/V delta 2 T cells by small nonprotein Ags is frequently observed after infection with various viruses, bacteria, and eukaryotic parasites. We suggested earlier that compounds synthesized by the 2-C:-methyl-D-erythritol 4-phosphate (MEP) pathway of isopentenyl pyrophosphate synthesis are responsible for the V gamma 9/V delta 2 T cell reactivity of many pathogens. Using genetically engineered Escherichia coli knockout strains, we now demonstrate that the ability of E. coli extracts to stimulate gamma delta T cell proliferation is abrogated when genes coding for essential enzymes of the MEP pathway, dxr or gcpE, are disrupted or deleted from the bacterial genome.