Tumescent liposuction: partitioning of lidocaine at a lower dose (252 mg/l)

Enhancement of Viable Adipose-Derived Stem Cells in Lipoaspirate by Buffering Tumescent with Sodium Bicarbonate

Background:

Fat grafting is a growing field within plastic surgery. Adipose-derived stem cells (ASCs) and stromal vascular fracture (SVF) may have a role in fat graft survival. Our group previously demonstrated a detrimental effect on ASC survival by the lidocaine used in tumescent solution. Sodium bicarbonate (SB) buffers the acidity of lidocaine. The purpose of this study was to determine whether SB buffering is a practical method to reduce ASC and SVF apoptosis and necrosis seen with common lidocaine-containing tumescent solution.

Methods:

Human patients undergoing bilateral liposuction for any indication were included in this study. An internally controlled, split-body design was utilized. Tumescent liposuction on one side of the body was conducted with tumescent containing lidocaine. On the opposite side, liposuction was conducted by adding SB to the tumescent. Tumescent solution and lipoaspirate pH were measured. Lipoaspirate from each side was processed for SVF isolation and ASC culture. The number of viable ASCs was counted and SVF apoptosis/necrosis was examined.

Results:

The pH of the SB-buffered tumescent was significantly higher than that of the standard tumescent, an effect also seen in the lipoaspirate. Adipose-derived stem cell survival in the SB-buffered lipoaspirate was approximately 53% higher. However, there was no significant difference in SVF apoptosis and necrosis between the groups.

Conclusions:

The acidic standard tumescent solution commonly used in liposuction diminishes ASC viability from lipoaspirates. Sodium bicarbonate buffering tumescent solution can enhance ASC viability, but does not affect SVF apoptosis and necrosis. We recommend buffering tumescent with SB to potentially improve fat graft take. Our findings advocate for further research investigating mechanisms and optimal harvest techniques that maximize SVF/ASC survival and the clinical effect on overall fat graft viability.

Fluid management in extensive liposuction: A retrospective review of 83 consecutive patients

Tumescent anesthesia makes it feasible to perform liposuction in an office setting. There are often patients who desire extensive liposuction on approximately 30% of total body surface area, which means the potential of fluid overload. In this study, the charts of 83 patients undergoing extensive liposuction were retrospectively reviewed. The intra-operative fluid ratio was 1.66 for the extensive liposuction. There were no episodes of pulmonary edema, congestive heart failure exacerbation, or other major complications. The average urine output in the operating room, the recovery room, and while on the floors was 1.35, 2.3, and 1.4 mL/kg/hour respectively. Intravenous (IV) fluid administration during operation was minimized to approximately 300 to 500 mL. The total volume of IV injection was also reduced to less than 1500 mL when the patient was in the recovery room and on the hospital floor. Our fluid management strategy in extensive liposuction reflects minimal risk of volume overload. Foley catheters are not applied and patients could resume oral intake in usual, so they can discharge after 6 hours of recovery room stay in our daily practice.

Morphometric analysis of high-intensity focused ultrasound-induced lipolysis on cadaveric abdominal and thigh skin

Non-focused ultrasound and high-intensity focused ultrasound (HIFU) devices induce lipolysis by generating acoustic cavitation and coagulation necrosis in targeted tissues. We aimed to investigate the morphometric characteristics of immediate tissue reactions induced by 2 MHz, 13-mm focused HIFU via two-dimensional ultrasound images and histologic evaluation of cadaveric skin from the abdomen and thigh. Acoustic fields of a 2 MHz, 38-mm HIFU transducer were characterized by reconstruction of the fields using acoustic intensity measurement. Additionally, abdominal and thigh tissues from a fresh cadaver were treated with a HIFU device for a single, two, and three pulses at the pulse energy of 130 J/cm² and a penetration depth of 13 mm. Acoustic intensity measurement revealed characteristic focal zones of significant thermal injury at the depth of 38 mm. In both the abdomen and thigh tissue, round to oval ablative thermal injury zones (TIZs) were visualized in subcutaneous fat layers upon treatment with a single pulse of HIFU treatment. Two to three HIFU pulses generated larger and more remarkable ablative zones throughout subcutaneous fat layers. Finally, experimental treatment in a tumescent infiltration-like setting induced larger HIFU-induced TIZs of an oval or columnar shape, compared to non-tumescent settings. Although neither acoustic intensity measurement nor cadaveric tissue exactly reflects in vivo HIFU-induced reactions in human tissue, we believe that our data will help guide further in vivo studies in investigating the therapeutic efficacy and safety of HIFU-induced lipolysis.

Tumescent Liposuction without Lidocaine

BACKGROUND

Our previous study demonstrated that lidocaine has a negative impact on adipose-derived stem cell (ASC) survival. Currently for large-volume liposuction, patients often undergo general anesthesia; therefore, lidocaine subcutaneous anesthesia is nonessential. We hypothesized that removing lidocaine from tumescent might improve stromal vascular fraction (SVF) and ASC survival from the standard tumescent with lidocaine. Ropivacaine is also a commonly used local anesthetic. The effect of ropivacaine on ASC survival was examined.

METHODS

Adults who underwent liposuction on bilateral body areas were included (n = 10). Under general anesthesia, liposuction on 1 area was conducted under standard tumescent with lidocaine. On the contralateral side, liposuction was conducted under the modified tumescent without lidocaine. Five milliliters of lipoaspirate were processed for the isolation of SVF. The adherent ASCs were counted after 24 hours of SVF culture. Apoptosis and necrosis of SVF cells were examined by Annexin/propidium iodide staining and analyzed by flow cytometry.

RESULTS

Average percentage of live SVF cells was 68.0% ± 4.0% (28.5% ± 3.8% of apoptosis and 3.4% ± 1.0% of necrosis) in lidocaine group compared with 86.7% ± 3.7% (11.5% ± 3.1% of apoptosis and 1.8% ± 0.7% of necrosis) in no-lidocaine group (P = 0.002). Average number of viable ASC was also significantly lower (367,000 ± 107) in lidocaine group compared with that (500,000 ± 152) in no-lidocaine group (P = 0.04). No significant difference was found between lidocaine and ropivacaine on ASC cytotoxicity.

CONCLUSIONS

Removing lidocaine from tumescent significantly reduced SVF and ASC apoptosis in the lipoaspirate. We recommend tumescent liposuction without lidocaine, particularly if patient's lipoaspirate will be used for fat grafting.

Local Anesthetics: What's New in Minimal Pain Injection and Best Evidence in Pain Control

SUMMARY

Local anesthesia in plastic surgery is undergoing a revolution. In the last 10 years, significant improvements in technique have permitted surgeons to do more and more under pure local anesthesia to increase patient safety and convenience while maintaining total patient comfort during the injection of the local anesthesia and while the procedure is accomplished. Many procedures which used to require sedation are now being performed without it. This article explores some of the new advances in local anesthesia such as painless blunt-tipped cannula local anesthetic infiltration, decreased pain with sharp needle tip injection, and long-lasting local anesthetics with delayed release from liposomal encapsulation. This article also examines the best evidence of the last 10 years of advances of pain control with local anesthesia.

Lidocaine-induced ASC apoptosis (tumescent vs. local anesthesia)

BACKGROUND

The purpose for the present study was to determine which anesthetic method, local anesthesia versus tumescent, is superior for liposuction in terms of adipose-derived stem cell (ASC) survival in lipoaspirate; which component, lidocaine versus lidocaine with epinephrine, in anesthetic solutions could affect ASC survival; and which mechanism, necrosis versus apoptosis, is involved in lidocaine-induced ASC death.

METHODS

Human lipoaspirates were harvested using standard liposuction technique. Individuals scheduled for liposuction on bilateral body areas gave consent and were included in the study. On one area, liposuction was conducted under local anesthesia with lidocaine/epinephrine. On the contralateral area, liposuction was accomplished with tumescent wetting solution containing lidocaine/epinephrine. Lipoaspirates were processed for the isolation of stromal vascular fraction (SVF). ASC survival was determined by the number of adherent ASCs after 24 h of SVF culture. Lidocaine dose-response (with or without epinephrine) on cultured ASCs was examined. Lidocaine-induced ASC apoptosis and necrosis was determined by Annexin V-FITC/Propidium Iodide (PI) assay and analyzed by flow cytometry.

RESULTS

All of the participants were female adults. The average age was 45 ± 4.0 years (±SEM) and the average BMI was 28 ± 1.0 (±SEM). Lipoaspirate samples (n = 14) treated by local anesthesia (n = 7/group) or tumescent anesthesia (n = 7/group) were investigated. Liposuction sites were located in the hip or thigh. The average number of adherent ASCs was 1,057 ± 146 k in the local anesthesia group, which was significantly lower than the 1,571 ± 111 k found in the tumescent group (P = 0.01). ASC survival was significantly lower in the lidocaine group and in a dose-dependent manner as compared to the correspondent PBS controls (P < 0.05 or P < 0.01). ASC survival was significantly lower in both the lidocaine and lidocaine with epinephrine groups when compared to PBS controls. Annexin/PI assay showed that ASC apoptosis (but not necrosis) in the lidocaine group was significantly higher than that in the corresponding PBS control (P = 0.026).

CONCLUSIONS

Tumescent anesthesia is the superior method for liposuction with respect to ASC preservation compared to local anesthesia. Lidocaine could cause significant ASC apoptosis.

The Forensic Implications of Liposuction: A Review

Liposuction continues to be one of the most popular cosmetic procedures in developed cultures worldwide. Since a 1999 report describing five liposuction-related deaths in New York City, three of which were incompletely explained, abundant analysis and literature has emerged. This paper aims to present the history of liposuction, review recent clinical safety/guidelines and forensic fatality literature, describe current and emerging trends and techniques, and offer an approach to the forensic investigation of these deaths.

Tumescent anaesthesia

Tumescent anaesthesia describes the practice of injecting a very dilute solution of local anaesthetic combined with epinephrine and sodium bicarbonate into tissue until it becomes firm and tense (tumescent). It was initially described in the field of liposuction but now surgical applications for the technique are widely varied ranging across vascular surgery, breast surgery, plastic surgery and ENT procedures. It is widely used in both hospital- and office-based environments and may form the sole method of anaesthesia for surgery. Advantages include a reduction in blood loss through both epinephrine-induced vasoconstriction as well as hydrostatic compression from the tumescent effect. Sodium bicarbonate reduces pain associated with the injection of an acidic local anaesthetic solution. Due to the unique pharmacokinetic profile of this technique lidocaine doses of 35 mg/kg bodyweight have been shown to be safe for liposuction procedures. Tumescent lidocaine is absorbed very slowly from subcutaneous tissues producing lower, and more delayed, peak blood levels compared to other routes, as well as extended postoperative analgesia. Slow systemic absorption allows the rapid hepatic plasma clearance of lidocaine to maintain safe local anaesthetic blood levels. This slow absorption from subcutaneous tissue has been likened to a depot injection. Careful attention must be given to appropriate local anaesthetic dosage alterations in cases of co-administration with agents affecting hepatic drug clearance or conditions reducing liver blood supply. Adherence to these pharmacological principles has produced an exemplary safety record for this technique to date.

Liposculpture and fat grafting for aesthetic correction of the gluteal concave deformity associated with multiple intragluteal injection of penicillin in childhood

BACKGROUND

The gluteal concave deformity, a complication of repeated intragluteal injections in childhood, is a relatively common complaint of many young women in China. This issue could be addressed by lipofilling, as the method could produce aesthetically acceptable results in correcting soft tissue contour defects.

METHODS

Twelve patients with bilateral gluteal concave deformities associated with repeated intragluteal injections were operated on from June 2006 to June 2010. The deformities were classified as major or minor. Overall satisfaction with body appearance after gluteal fat grafting and liposculpture was rated on a scale of 1 (poor), 2 (fair), 3 (good), 4 (very good), and 5 (excellent). The evaluation was performed at 3-44 months after surgery.

RESULTS

The average volume of fat injected was 196.9 ± 41.4 ml. No serious adverse events occurred. One patient with major deformity had one additional fat grafting procedure. One patient developed cellulitis in the feet and lower legs, upon which the grafted areas were incised and drained on suspicion of infection but with negative cultures. The patient recovered uneventfully with intravenous antibiotic application for 7 days. At the office visit nine cases judged that their appearance after the operation as "very good" (4) to "excellent" (5) and three cases responded that their contour was "good." Improvement in skin texture and alleviation of the pigmentation in the concave area were observed in all cases during the 3-44-month follow-up intervals after the fat grafting, and softening of the hypertrophic scar was also observed as early as 1 month after the fat grafting and continuously improved during the 12-month follow-up.

CONCLUSION

Autologous lipografting for gluteal concave deformity, combining a liposculpture procedure adjacent to the defects, accomplishes good aesthetic results with high patient satisfaction. The key to success is complete release of fibrosis adhesion, meticulous manipulation of fat grafts, and multitunnel and multiplane injections to ensure maximum take of the grafts.

LEVEL OF EVIDENCE IV

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