Circumferential shoulder laceration after posterior axilla sling traction: a case report of severe shoulder dystocia

A critical evaluation of the external and internal maneuvers for resolution of shoulder dystocia

In the management of shoulder dystocia, it is often recommended to start with external maneuvers, such as the McRoberts maneuver and suprapubic pressure, followed by internal maneuvers including rotation and posterior arm delivery. However, this sequence is not based on scientific evidence of its success rates, the technical simplicity, or the related complication rates. Hence, this review critically evaluates the success rate, technique, and safety of different maneuvers. Retrospective reviews showed that posterior arm delivery has consistently higher success rates (86.1%) than rotational methods (62.4%) and external maneuvers (56.0%). McRoberts maneuver was thought to be a simple method, however, its mechanism is not clear. Furthermore, McRoberts position still requires subsequent traction on the fetal neck, which presents a risk for brachial plexus injury. The 2 internal maneuvers have anatomic rationales with the aim of rotating the shoulders to the wider oblique pelvic dimension or reducing the shoulder width. The techniques are not more sophisticated and requires the accoucher to insert the correct hand (according to fetal face direction) through the more spacious sacro-posterior region and deep enough to reach the fetal chest or posterior forearm. The performance of rotation and posterior arm delivery can also be integrated and performed using the same hand. Retrospective studies may give a biased view that the internal maneuvers are riskier. First, a less severely impacted shoulder dystocia is more likely to have been managed by external maneuvers, subjecting more difficult cases to internal maneuvers. Second, neonatal injuries were not necessarily caused by the internal maneuvers that led to delivery but could have been caused by the preceding unsuccessful external maneuvers. The procedural safety is not primarily related to the nature of the maneuvers, but to how properly these maneuvers are performed. When all these maneuvers have failed, it is important to consider the reasons for failure otherwise repetition of the maneuver cycle is just a random trial and error. If the posterior axilla is just above the pelvic outlet and reachable, posterior axilla traction using either the accoucher fingers or a sling is a feasible alternative. Its mechanism is not just outward traction but also rotation of the shoulders to the wider oblique pelvic dimension. If the posterior axilla is at a higher sacral level, a sling may be formed with the assistance of a long right-angle forceps, otherwise, more invasive methods such as Zavanelli maneuver, abdominal rescue, or symphysiotomy are the last resorts.

Prescriptive and proscriptive lessons for managing shoulder dystocia: a technical and videographical tutorial

This tutorial of the intrapartum management of shoulder dystocia uses drawings and videos of simulated and actual deliveries to illustrate the biomechanical principles of specialized delivery maneuvers and examine missteps associated with brachial plexus injury. It is intended to complement haptic, mannequin-based simulation training. Demonstrative explication of each maneuver is accompanied by specific examples of what not to do. Positive (prescriptive) instruction prioritizes early use of direct fetal manipulation and stresses the importance of determining the alignment of the fetal shoulders by direct palpation, and that the biacromial width should be manually adjusted to an oblique orientation within the pelvis-before application of traction to the fetal head, the biacromial width is manually adjusted to an oblique orientation within the pelvis. Negative (proscriptive) instructions includes the following: to avoid more than usual and/or laterally directed traction, to use episiotomy only as a means to gain access to the posterior shoulder and arm, and to use a 2-step procedure in which a 60-second hands-off period ("do not do anything") is inserted between the emergence of the head and any initial attempts at downward traction to allow for spontaneous rotation of the fetal shoulders. The tutorial presents a stepwise approach focused on the delivering clinician's tasks while including the role of assistive techniques, including McRoberts, Gaskin, and Sims positioning, suprapubic pressure, and episiotomy. Video footage of actual deliveries involving shoulder dystocia and permanent brachial plexus injury demonstrates ambiguities in making the diagnosis of shoulder dystocia, risks of improper traction and torsion of the head, and overreliance on repeating maneuvers that prove initially unsuccessful.

Intrauterine fetal death followed by shoulder dystocia and birth by modified posterior axillary sling method: a case report

Background

Various manoeuvres such as McRoberts position, suprapubic pressure, rotational methods, posterior arm extraction and all-four position (HELPERR) have been proposed for relieving shoulder dystocia with variable success. Posterior axillary sling method using a rubber catheter was proposed in 2009 but has not been widely used. We modified this method using ribbon gauzes and a long right-angle forceps and report a successful case.

Case presentation

A 44 years old parity one Chinese woman with a history of a caesarean delivery and poorly controlled type 2 diabetes mellitus was admitted to the Accident and Emergency Department for advanced stage of labour at term. Upon arrival, intrauterine fetal demise was diagnosed with severe asynclitism causing obstruction at the perineum. Episiotomy resulted in birth of the fetal head. The fetal posterior right shoulder, however, remained very high up in the pelvis and HELPERR methods failed to extract the shoulders. We then tied two long ribbon gauzes together, and guided its knot to the anterior aspect of the posterior axilla. By using a long right-angle forceps (24 cm long) to grasp the knot on the posterior side of the axilla and pulling it through, a sling was formed. Traction was then applied through the sling to simultaneously pull and rotate the posterior shoulder. A stillbirth of 3488 g was finally extracted.

Conclusions

We modified the sling method by using two ribbon gauzes, tied together and a right-angle forceps with several advantages. Compared to a rubber catheter, ribbon gauze with a knot can be easily held between the fingers for easy guidance past the fetal axilla. It is also thin, non-elastic and stiff enough to ensure a good grip for traction. The long and slim design of the right-angle forceps makes it easy to pass through a narrow space and reach the axilla high up in the pelvis. We emphasize simultaneous traction and rotation, so that the shoulders are delivered through the wider oblique pelvic outlet dimension.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04126-4.