BOB Ped Surg 2023 - Brittany Hegde, PAPS - Presentation

Why This Exists

Pectus excavatum is the most common thoracic wall anomaly in pediatric patients 0:00. The minimally invasive repair — MIRPE, or the Nuss procedure — replaced open approaches two decades ago and brought real advantages: shorter operative time, less blood loss, faster return to baseline 0:00. But it remains an intensely painful operation 0:00. A metal bar is tunneled beneath the sternum and left in place for years. Historically, controlling that pain required epidurals, patient-controlled analgesia pumps, scheduled IV narcotics, and multiday admissions with all the cost and risk that entails 0:00. Cryoablation of the intercostal nerves emerged as an alternative: freeze the nerves intraoperatively, achieve weeks to months of analgesia, and potentially send patients home sooner with less opioid exposure 1:00.

The Core Clinical Problem

The bar placement itself — elevating the sternum, remodeling the anterior chest wall — generates severe postoperative pain that peaks in the first days and can persist for weeks 0:00. Traditional multimodal analgesia works but carries trade-offs: epidurals require monitoring and can fail or migrate; IV narcotics bring nausea, ileus, and respiratory depression; prolonged hospitalization increases infection risk and cost 0:00. The question is whether a single intraoperative nerve ablation can replace or substantially reduce all of that 0:00.

How Cryoablation Works in This Context

The technique is thoracoscopic 1:00. After placing the pectus bar, the surgeon inserts cryoprobes through the existing port sites and applies them directly to the intercostal nerves under visualization, typically bilaterally in the third through seventh intercostal spaces 1:00. The probe subjects the nerve to extreme cold, inducing Wallerian degeneration without disrupting the nerve sheath — meaning the nerve will eventually regenerate, but analgesia is estimated to last weeks to months 1:00. It is a reversible nerve block with a duration far exceeding any local anesthetic 1:00.

The appeal is straightforward: one intervention, performed while the patient is already under anesthesia, that may eliminate the need for epidural placement, reduce opioid consumption, and shorten hospital stay 0:00. The risk profile appears favorable — the nerves regenerate, the technique is performed under direct vision, and early reports suggested no increase in complications 0:00.

What This Study Found

This is a single-center retrospective analysis from a pediatric institution that adopted cryoablation in November 2016 3:00. They compared 44 patients: those treated before cryo was available and those treated afterward 4:00. The groups were well-matched for age, weight, insurance status, race, presenting symptoms, and Haller index 4:00. All patients after November 2016 received cryoablation; none before that date did, creating a clean pre-post comparison 3:00 4:00.

The analysis used Bayesian models with a neutral prior — meaning they started from the assumption of no treatment effect and let the data shift the probability 5:00. Cryo use was associated with an 89% probability of reducing total hospital costs, with a mean difference of $880 5:00. That cost reduction likely came from shorter admissions: there was a 100% probability of reduced length of stay during the index hospitalization 5:00, and a 99% probability of reduced total hospital days when readmissions within 90 days were included 5:00. Complication rates did not differ between groups 6:00, and the Bayesian model suggested a 70% probability that cryoablation actually reduced complications 6:00.

The cost figure accounts for the additional equipment required to perform cryoablation 5:00, meaning the savings are net of the intervention cost. The mechanism is not mysterious: patients go home faster, use fewer nursing hours, require less pharmacy support, and avoid the monitoring overhead of epidurals or PCA pumps 5:00.

Where Uncertainty Remains

This is a 44-patient series from one institution 4:00. The pre-post design is clean, but it cannot control for secular trends — changes in anesthesia practice, nursing protocols, or discharge criteria that may have occurred independently over the same decade 2:00. The study does not report opioid consumption, pain scores, or patient-reported outcomes, so we know patients left the hospital sooner but not precisely why. The long-term sensory outcomes of intercostal cryoablation in adolescents are not well characterized 1:00. Nerve regeneration is expected, but the timeline and completeness of recovery are not tracked here.

The findings are consistent with prior work from the same group showing reduced opioid use and shorter stays 0:00, but external validation is absent. The authors appropriately call for multicenter studies 2:00.

When to Consider This Approach

For pediatric surgeons performing pectus repair, cryoablation is now a standard option at many centers 0:00. The technique requires thoracoscopic skill and the appropriate equipment, but it is performed during an operation that already uses thoracoscopy for bar placement 1:00. The decision is made preoperatively, not at the bedside.

For referring clinicians, this does not change the indications for pectus repair itself — those remain based on Haller index, cardiopulmonary symptoms, and patient preference 0:00. But it does mean that the postoperative course may be shorter and less opioid-intensive than it was a decade ago 5:00 5:00, which is worth discussing with families during preoperative counseling. If a patient is being evaluated for repair, ask the surgical team whether they use cryoablation and what their typical length of stay is. The answer will vary by center, but the trajectory is toward shorter admissions and less reliance on neuraxial analgesia 0:00 5:00.

Why This Exists

Pectus excavatum is the most common thoracic wall anomaly in pediatric patients 0:00. The minimally invasive repair of pectus excavatum (MIRPE) replaced open approaches because it reduces operative time, blood loss, and recovery duration 0:00. But the procedure remains intensely painful, historically requiring multiple analgesic modalities and substantial narcotic doses 0:00. Thoracoscopic intercostal nerve cryoablation emerged as an attempt to address this pain problem at its source 0:00.

The Core Problem

MIRPE involves placing a curved metal bar beneath the sternum to correct the chest wall deformity 0:00. The bar sits against the intercostal spaces, and the dissection required to position it traumatizes multiple intercostal nerves 0:00. Traditional pain control relied on epidurals, patient-controlled analgesia, scheduled opioids, and adjunctive nerve blocks—a stack of interventions that extended hospital stays and carried their own risks 0:00. The question was whether ablating the intercostal nerves during the index operation could provide sustained analgesia without introducing new complications 0:00.

How Cryoablation Works in This Context

Cryoablation is performed thoracoscopically using specialized nerve block probes inserted through the same port sites used for the repair 1:00. Under direct visualization, the surgeon activates the probes at the intercostal nerves, typically bilaterally in spaces three through seven 1:00. The extreme cold subjects the nerves to Wallerian degeneration—the axons are damaged but the nerve sheath remains intact, allowing eventual regeneration 1:00. Pain control is estimated to last weeks to months 1:00.

The technique adds equipment cost and a few minutes of operative time 5:00. The trade-off is whether that upfront investment reduces downstream resource use—hospital days, readmissions, and complications—enough to justify adoption 5:00.

Evidence From a Single-Center Cohort

This study examined pediatric patients who underwent MIRPE between 2011 and 2021 at one institution 3:00. Cryoablation was introduced in November 2016, and every patient treated afterward received it 3:00. The cryoablation group comprised the majority of patients studied 4:00. Both groups were predominantly male 4:00. The groups were similar in age, body habitus, insurance status, race, presenting symptoms, and Haller index 4:00.

The analysis used Bayesian models with a neutral prior—an approach that yields probability statements rather than p-values 5:00. Cryoablation was associated with high probability of reducing total hospital costs, with a mean difference of $880 5:00. This occurred despite the added equipment expense 5:00. The cost reduction appears driven by shorter hospital stays 5:00. Cryoablation carried very high probability of reducing index admission length of stay 5:00 and very high probability of reducing total hospital days when readmissions within 90 days were included 5:00.

Complications did not increase 6:00. The incidence of postoperative complications was similar between groups 6:00, and cryoablation was associated with high probability of reducing complications 6:00. Hospital cost data were inflation-adjusted using the consumer price index for medical services 3:00.

Where Uncertainty Remains

This is a small, single-center, pre-post study 3:00 3:00. The introduction of cryoablation in 2016 means the comparison is also a comparison across time—any secular trends in pain management, surgical technique, or discharge criteria could confound the results 3:00. The study does not report opioid consumption, which was a primary outcome in the institution's earlier work 0:00. Without that data, it is unclear whether the shorter stays reflect better pain control, different discharge thresholds, or both.

The Bayesian probabilities are not effect sizes 5:00. High probability of cost reduction does not tell you the magnitude of certainty around the $880 figure, nor does it address whether that difference is clinically meaningful at scale 5:00. The probability of complication reduction, given that baseline complication rates were already similar, suggests the signal is weak 6:00 6:00.

Longer-term outcomes are absent 5:00. Cryoablation causes temporary nerve injury; regeneration is expected but not guaranteed 1:00. Chronic neuropathic pain, numbness, or dysesthesia in the distribution of the ablated nerves would be relevant, but the 90-day follow-up window does not capture that 5:00.

When to Consider This Approach

If you are referring a patient for pectus excavatum repair, ask whether the surgeon uses cryoablation and what their institutional data show 0:00. The technique appears to shorten hospital stays without increasing perioperative complications, which matters for adolescents and their families 5:00 5:00 6:00. The cost analysis is institution-specific—equipment contracts, baseline length of stay, and reimbursement structures vary—but the direction of effect is plausible 5:00 3:00.

For surgeons considering adoption, this study suggests cryoablation is worth evaluating in your own population 3:00. The technique is not complex if you are already performing thoracoscopy, but it does require equipment and a learning curve 1:00. The case for adoption strengthens if your baseline MIRPE length of stay is long or if you are trying to reduce opioid exposure in this population 5:00 5:00.

The call for multicenter validation is appropriate 3:00. A single-center pre-post study can generate a hypothesis and justify further work, but it cannot establish standard of care 3:00 3:00.