Reply to Response by Manzaneda to “Waistline Aesthetic Slimming by Puncture and Parallel Approach for Rib Remodeling Procedures”

We appreciate the opportunity to clarify several points raised in the recent Letter to the Editor concerning our article on Waistline Aesthetic Slimming by Puncture (WASP) and the parallel approach to rib remodeling.^1,2 We agree that rib remodeling is a developing field that requires careful methods, consistent definitions, and transparent reporting.

TECHNIQUE FAMILIES AND ANATOMIC RATIONALE

Two technical philosophies currently frame rib remodeling:

• Parallel corticotomy (WASP, Ultrasonic and Ultrasound-Assisted Improvement of the Silhouette of the Torso [UUAIST], Ribcage Osteosintetis [RIBOSS], Kudzaev original work): along the external rib cortex, respecting rib curvature, typically with continuous irrigation and real-time ultrasound verification.^2-5 The trajectory maintains distance from the pleura and facilitates standardized imaging checkpoints (depth, pleural excursion, and postmaneuver integrity).

• Perpendicular puncture (RibXCar): an orthogonal entry toward the pleura using a modified tip in some reports.⁶ The shortest path to the pleural plane reduces tactile margin for error and places greater weight on energy control and tip surface behavior.

This anatomic difference informs both safety expectations and how endpoints are verified. Intraoperative ultrasound, when standardized, improves reproducibility for either approach and should be routine (Table 1).

Table 1.

Parallel vs Perpendicular (to the Pleural Plane) Techniques for Rib Remodeling

Feature	Parallel approach (WASP, RIBOSS, UUAIST, Kudzaev’s)	Perpendicular approach (RibXCar)
Direction of corticotomy	Along the outer cortical surface, parallel to the pleura	Perpendicular puncture toward the pleura
anatomical safety	Minimizes risk of pleural or vascular injury by respecting rib curvature	Higher probability of pleural penetration because of puncture trajectory
Instrument design	Blunt/diamond tip, factory-coated and fluid-cooled (WASP only)	Manually straightened and sharpened, protective coating removed
thermal control	Internal manufacturer irrigation (fluid-cooled) prevents overheating	Manual time restriction (eg, 6 s pulse limits) to avoid burns; reliance on external cooling
Reported serious complications	0% pneumothorax/hemothorax across multiple published series	2.6% incidence of pneumothorax/hemothorax reported by the author in 1 study

WASP, Waistline Aesthetic Slimming by Puncture.

SAFETY SIGNALS, DENOMINATORS, AND FOLLOW-UP

The letter asserts that parallel techniques carry higher anatomic risk. Across multiple series within the parallel family, authors consistently report 0% pleural complications (pneumothorax or hemothorax) with ultrasound guidance and manufacturer-recommended irrigation.^2-5 In contrast, perpendicular reports include nonzero pleural events: a multicenter survey cites ∼2.65% “serious complications” that include pleural injuries, and early-period clinical experience described pleural events within the data-collection window. We also feel that follow-up length is central. Several perpendicular reports rely on ≤3- to 6-month windows or aggregate program timelines. We feel that such intervals are less than ideal for the capture of late events such as neuropathic pain, delayed contour changes, or reoperations. Our own publications and those in the parallel family emphasize a minimum of 6- to 12-month follow-up targets whenever feasible and explicitly discuss attrition. More broadly, when complication rates are presented from recall-based surveys (respondent-level denominators rather than patient-level data), conclusions should be framed cautiously and paired with clear definitions. The anatomical rationale—that a perpendicular trajectory provides a proprioceptive “stop”—is an experiential heuristic, not a guaranteed safety mechanism. We strongly believe that a parallel approach, by respecting the rib curvature and avoiding an aggressive puncture trajectory, can be safer based on current clinical data and consistent with guidelines for rib fracture management and minimally invasive rib procedures.^7-11

INSTRUMENT DESIGN AND THERMAL SAFETY

Surface coatings and manufacturer-recommended irrigation on ultrasonic or oscillatory tips are intended to reduce friction, wear, and heat at the bone–metal interface. The instrument modification for RibXCar perpendicular approach, in our opinion, may raise concerns regarding thermal safety and manufacturer guidelines.¹² Removing protective coatings, disabling irrigation (eg, water-jet off), or relying on external syringe cooling while delivering timed pulses changes the thermal environment in ways that may be detrimental. On the other hand, the WASP Tip adheres to factory finishes and active, central-channel irrigation, designed for safety and efficiency (HD Tip—PATENT Pending). It also employs a double-tripod mechanism for controlled movement.

CONCLUSIONS

In conclusion, WASP and related parallel techniques are anatomically principled, ultrasound-verified, and device-compliant approaches that—across published series—report 0% pleural complications and incorporate validated patient reported outcomes measures. In our publication, our goal is not to disparage any group but to ensure that the specialty advances on a foundation of verifiable methods, harmonized definitions, adequate follow-up, and transparent outcomes.

Disclosures

The authors declared no potential conflicts of interest with respect to the research, authorship, and publication of this article.

Funding

The authors received no financial support for the research, authorship, and publication of this article.