hello? Chaebi Everyone, Dr. Ai lipoplastic surgery. Han Gru (Chief Surgeon)It is.
The standard medical name in the title is ‘Powered liposuction (PAL)’and ‘Traditional negative pressure liposuction (SAL)’ instead '기계식 지방흡입'and ‘Handmade’The reason why the expression is included is because it is a familiar term that is currently widely spread among patients in private practice for marketing purposes. However, there is no automated method where a machine performs surgery on its own. Both PAL and SAL methods are ultimately surgeries performed from start to finish by the doctor holding the handpiece and stroking it.It is.
“Between Power-Assisted Liposuction (PAL, Power-Assisted Liposuction), which uses the power of a motor to finely vibrate the tube, and traditional Negative Pressure Liposuction (SAL, Suction-Assisted Liposuction), which involves suctioning using only the doctor’s touch without a vibration motor, is there really a scientific paper designed well enough to change the patient’s final surgical outcome?”
If we open the original text of the actual medical academic database (PubMed), not just a marketing phrase, and verify the design piece by piece, we will encounter loopholes behind the paper that we believed to be 'scientific evidence'. In today's column, I looked for and read comparative papers between PAL and SAL. 5-step critical verification processWe want to share this transparently.
PAL vs SAL landmark paper verification process at a glance
• Question: “What representative randomized controlled trials (RCTs) have demonstrated significant differences between PAL and SAL?”
• Surface area reported: increased suction rate (mL/min), reduced surgical time, and reduced arm fatigue for surgeons (Katz et al., 2001)
• Question: “What is the body mass index (BMI) of the patients studied? Weren’t they mainly selected for overweight and obesity?”
• Limitations found: Individual height, weight, and BMI values are not indicated → A defect in ‘generalization (external validity)’ in which the mechanical time reduction effect is exaggerated when focusing on the obese group
• Question: “After checking the original text, isn’t the total number of patients only 18?”
• Limitations found: Minimum statistics were obtained through symmetrical comparison (split-body), but actual safety could not be verified due to skin necrosis, discoloration, and asymmetry with a sample of 18 people.
• Insight: “Aren’t the authors of the paper themselves commercial stakeholders in the organizations and techniques they promote?”
• Academic evidence: bias in positive conclusions due to financial interests (Lopez et al., 2015) and lack of independent reproducibility review by opposing experts.
• Linguistic analysis: Excessive superiority framing (Spin phenomenon) compared to the restrained description of orthodox medical and surgical papers
• Surgeon's conclusion: What is more important than the vibration of the motor is the hydrodynamic handling of fat lobules like grape clusters and the preservation of thread blood vessels (micro blood vessels).
1. The superficial results presented in the paper and the limitations of the ‘hidden BMI distribution’
In academia, the most widely cited early literature comparing PAL and SAL as a prospective randomized controlled trial (RCT) was published in 2001. Dermatologic SurgeryThis is a multicenter study by Katz et al. published in [1]. The researchers used a split-body design, dividing the left and right symmetrical parts of a patient's body and inhaling on one side with the PAL and the other with the SAL.
But as a surgeon, the next question I asked was: “Is the BMI (body mass index) distribution of the patients who participated in the study provided?”It was. Surprisingly, the original paper did not specify the patients' individual height or BMI values, but only presented basic epidemiology summary values such as the average range of weight, age, and gender [1].
① Disparity between internal validity (accuracy within the study) and external validity (generalizability)
The thicker the fat layer and the greater the suction volume, the greater the effect of reducing time and doctor fatigue caused by the machine's reciprocating vibration. On the other hand, in normal weight to slightly overweight patients who want detailed line sculpting, the time difference between PAL and SAL may be clinically insignificant. The fact that epidemiological summary values are lumped together so that they cannot be distinguished is an obvious limitation that makes it difficult to generalize the study results to all patients.
2. Sample of only 18 people (N=18), and structural conflict of interest in plastic surgery papers
The bigger shock I encountered when I read the original text of the paper directly was The total number of study subjects is only 18 (1 male, 17 female).was true [1]. The very small sample of 18 people was only an initial exploratory study (pilot study) to gauge the operating speed of the device. With such a small sample, patients are really worried. It is completely statistically impossible to verify differences in serious side effects, such as skin necrosis, severe bruising and hematomas, uneven skin asymmetry, and permanent pigmentation.[3].
Compared to other medical and surgical departments, plastic surgery papers The relationship is so strong that the authors themselves are direct commercial stakeholders of the research results. In fact, researchers at Johns Hopkins University (Lopez et al., 2015) Plastic and Reconstructive SurgeryAccording to an analysis published in , plastic surgery papers written by researchers with a financial conflict of interest (COI) were statistically significantly more likely to reach a ‘positive and superior conclusion’ about a specific device or procedure [4].
3. Overuse of “Significantly” and “Than”: Physics of Flesh and Preservation of Blood Vessels
| Lexical and descriptive analysis items | Academic norms for orthodox internal medicine/essential surgery papers | Description of the relevant plastic surgery instrument comparison paper (Katz et al.) |
|---|---|---|
| Framing of the Title | Adoption of a value-neutral comparison structure (Comparative Evaluation...) | A promotional title that puts ‘The Benefits of Powered Liposuction...’ of a specific device at the forefront. |
| Usage of "Significantly" | If the level is N=18, immediately add a proviso that "the sample is small and interpretation requires caution." | Exaggeration of clinical overwhelmingness by repeatedly placing “Significantly faster” and “Significantly less fatigue” |
| Comparative composition using “Than” | Present neutral phrases such as “Relative to” and “Compared with” and confidence intervals | Degrading the traditional manual method (SAL) by using “Faster than,” “Easier than,” and “Superior to” in succession. |
The fat in our body is a lump (fat lobules, 1-4 mm) tightly bound with a collagen network like a small bunch of grapes [6, 7, 8]. As the diameter of the pipe becomes too thin, the internal flow resistance rapidly increases (R ∝ 1/r⁴), and grape cluster grains may get caught in the hole, causing the pipe to become clogged (inspissed fat). Only selection of the appropriate Tapered Bullet Tip and Mercedes Hole cannula suitable for the size of the fat lobules and delicate handling by the surgeon creates a smooth line.
If the thin blood vessel network under the skin is injured through rough manipulation relying on rapid vibration, skin necrosis, hematoma, long swelling, and the iron content in the blood seeping into the skin can occur. Permanent dark skin staining (pigmentation) due to hemosiderin depositionThis leaves us with [9, 10].
[Surgeon Dr. Han Gru (Chief Surgeon)'s treatment principles: Principles of truthful treatment without exaggeration]“We do not rely on the names of expensive expensive equipment, commercially inflated numbers of papers, or promotional slogans from provocative YouTubers. We honestly diagnose the patient’s body condition as it is, transparently explain the limitations of the surgery, and prove it only with the results in the operating room.”
4. Frequently asked questions about liposuction equipment (PAL vs SAL) and medical literature
Not necessarily so. The key advantage of PAL demonstrated in the paper is that it 'reduces the arm fatigue of the operating surgeon and passes through hard fibers quickly.' The key to determining bruising, swelling, and discoloration depends on how precisely the surgeon suctions at a precise depth and angle without damaging the blood vessels under the skin (vascular preservation technique).
PAL itself is by no means a bad device. In areas where the skin is particularly hard and tough, such as the back or gynecomastia areas, or in areas with fibrotic reoperation, it is an excellent auxiliary tool to reduce the physical expenditure of the doctor. However, the essence is the doctor's detailed manual skill in controlling the machine.
For those of normal weight or who wish to partially sculpt the body line, authentic manual handling (SAL), which involves directly feeling the thickness of fat grains and skin in 1mm increments with the fingertips through a thin tube and delicately trimming them, is very advantageous in producing smooth results.