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Biomedical subjects

Samuel M Lam

Publications and source records attributed to Samuel M Lam.

At least 19 recordsLinked to original sources
PubMed2006

Injectable poly-L-lactic acid (Sculptra): technical considerations in soft-tissue contouring.

BACKGROUND: Poly-L-lactic acid gained U.S. Food and Drug Administration approval for use in human immunodeficiency virus-related facial lipoatrophy in August of 2004. Since that time, it has become available for use in the United States for human immunodeficiency virus facial lipoatrophy patients and for off-label uses in other areas for soft-tissue contouring. This article is intended to enumerate reconstitution, injection techniques, management, and avoidance of complications. METHODS: The authors have pooled their experiences to arrive at a consensus opinion for recommendations on treatment protocols for injectable poly-L-lactic acid use. RESULTS: This article prescribes techniques to achieve safer, consistent results while minimizing risks of complications with injectable poly-L-lactic acid. Although the product has been used widely in Europe since 1999, physicians in the United States have only recently begun to explore the uses of Sculptra as a volumizing agent in the face and the body. U.S. physicians have benefited from the European experience with this product, including early problems secondary to overaggressive use, low-volume reconstitution, higher volume injection of product at one session, and inadequate time between injection sessions. CONCLUSIONS: The authors therefore have opted for a more conservative approach in their treatment recommendations. Higher volume dilution (8 to 12 cc), fewer vials used at each session, injections placed in the subcutaneous plane without any product being placed in the dermis, adequate time between injection sessions (at least 6 weeks), and postinjection patient massage should decrease the risks and avoid the potential complications associated with poly-L-lactic acid soft-tissue augmentation.

Adult↗
PubMed2005

Aesthetic facial surgery for the asian male.

Cosmetic surgery of the Asian face has become increasingly popular in the Far East and the West. The Asian male identity has undergone an evolution in Western media toward a more positive change. The standards of beauty have also changed, being defined by more multicultural models and styles of dress than before. To undertake cosmetic surgery of the Asian face, particularly of the Asian male, requires a different psychological understanding of the individual as well as an entirely different surgical technique in most cases. This brief article does not delve into the technical details of each procedure but concentrates on the salient differences in how to approach the Asian male patient for each of the different procedures, including Asian blepharoplasty, augmentation rhinoplasty, lip reduction, dimple fabrication, otoplasty, facial contouring and aging face procedures, and hair restoration.

Aging↗
PubMed2004

Secondary rhinoplasty of the Asian nose: correction of the contracted nose.

The contracted nose is a unique entity that follows primary rhinoplasty in the Asian patient. The proposed reasons for this complication are capsular contraction from a silicone nasal implant, pressure necrosis of the lower lateral cartilage resulting from the nasal implant, and infection after alloplastic implantation. The two principal anatomic constituents that must be addressed at the time of secondary rhinoplasty are the lower lateral cartilages and the skin envelope. The lower lateral cartilages should be derotated, projected, and transfixed with an extended spreader graft. Additional onlay grafting may be required to provide greater nasal tip derotation and projection. A transcolumellar incision situated at the columellar-labial angle permits undermining of the upper lip skin to release tension on the incision. If the nasal tip retraction is severe, then the skin envelope may be insufficient to provide coverage to the new cartilaginous framework. In this case, a paramedian forehead flap is recommended to provide adequate tissue coverage. Correction of alar-columellar disparity should be undertaken with composite grafting only after 6 months have transpired to gauge the ultimate relation between the alae and columella. Infection that arises after correction of the contracted nose can be devastating. It should be treated aggressively, but tailored to the severity of the infection. Wound tension along the columella may predispose to skin necrosis and consequent cartilage exposure, which should be managed in turn with prostaglandin emollients to accelerate wound healing and to prevent infection.

Adult↗
PubMed2004

Practical considerations in the treatment of capillary vascular malformations, or port wine stains.

Port wine stains (PWSs) represent the most common type of vascular malformation. With the advent of pulsed-dye laser therapy, treatment of these lesions has become achievable with minimal prospect of adverse scarring. Although many scientific articles have heralded the favorable outcomes in patients who have undergone pulsed-dye laser treatments, few articles address the practical considerations (pre-, intra-, and postoperative) that must be followed to ensure success. This article presents the 10-year experience of the senior author (EFW) in the management of port wine malformations and the clinical insights that have been gleaned from that extensive experience. Introductory remarks are made as to the nature of PWSs, related syndromes, and the evolution of treatment; practical management guidelines are then discussed.

Child↗
PubMed2004

A cadaveric analysis of the ideal costal cartilage graft for Asian rhinoplasty.

Augmentation rhinoplasty of the Asian nose may be effectively accomplished with alloplastic materials. However, certain circumstances mandate the use of autologous grafts (e.g., dorsal augmentation that exceeds 8 mm and patient intolerance of alloplastic implants). Septal and auricular cartilages are inadequate for dorsal augmentation of the Asian nose. The use of costal cartilage for autologous augmentation in select Asian patients has proven to be a reliable method in more than 500 operative cases during a 10-year period. This study was designed to evaluate the ideal costal cartilage graft for augmentation rhinoplasty. Forty-two preserved cadavers were studied for the relationship of the individual rib cartilages to the surrounding tissue and for the length and caliber of each costal cartilage. The seventh rib was found to be the ideal rib graft by virtue of its safe location and overall size for grafting. The seventh rib is situated over the abdominal cavity, so the risk of pneumothorax is insignificant. The internal thoracic artery and vein descend in close apposition behind the first to sixth ribs but begin a course medial to the ribs inferior to this point, and therefore vascular injury during seventh-rib harvesting is unknown. The seventh rib also provides the greatest overall available length (90.7 mm, right; 89.6 mm, left) and thickness (17.6 mm, right; 17.5 mm, left). Despite the more conspicuous location of the incision required to harvest the seventh rib, the limited 3-cm incision that is used has healed favorably in almost all cases. The other major drawback for seventh-rib harvesting is the dissection required through the overlying rectus abdominis muscle, but little technical difficulty or postoperative morbidity is added with muscle dissection. The seventh rib is advocated as the ideal choice for augmentation rhinoplasty and potentially other recipient sites.

Asian People↗
PubMed2003

A new paradigm for the aging Asian face.

Traditionally, Asians have been thought to age more gracefully than Caucasians. The resistance to aging in the Asian patient was credited to the thicker dermis of Asian skin that contains greater collagen and the darker pigment that protects against photoaging. Although these statements are true, the authors propose a new paradigm that explains how the illusion of Asian youthfulness may be understood. The "baby model" purports that the Asian face has many attributes similar to an infant, including a wider and rounder face, higher eyebrow, fuller upper lid, lower nasal bridge, flatter midface, apparently more protuberant lips, and more receded chin. These commonalities between the infant and the Asian compel the viewer to perceive the Asian face as more youthful. However, the Asian face is subjected to a greater amount of gravitational force due to weaker skeletal support, heavier soft tissue, larger amount of malar fat, thicker skin, and a weaker chin. Facial rejuvenative surgery should always be cognizant of the propensity of the Asian skin to unfavorable healing, need for greater tissue suspension, and more conspicuous temporal alopecia. Asian aesthetics that differ and converge with Western ideals are reviewed so that the Western surgeon in particular can comprehend the Asian conception of youthful beauty.

Adipose Tissue↗
PubMed2003

A systematic approach to rhinoplasty of the Japanese nose: a thirty-year experience.

The Japanese nose exhibits a combination of leptorrhine and mesorrhine features that mandates an innovative treatment strategy. Unlike elsewhere in Asia, the Japanese nose often has adequate dorsal height, and at times even dorsal convexity, but maintains a more retruded and amorphous tip configuration. The proposed systematic approach to Japanese rhinoplasty is divided into four categories: (1) dorsal augmentation with or without tip augmentation, (2) dorsal reduction with tip augmentation, (3) tip augmentation only, and (4) dorsal reduction only. The use of autologous and alloplastic materials to achieve the desired aesthetic objectives is described herein. A layered auricular graft technique is outlined for tip surgery, and a unique nasal implant design is discussed.

Asian People↗
PubMed2003

The basic science of botulinum toxin.

Understanding the basic science of botulinum toxin should serve as a fundamental first step for clinical therapy. This article endeavors to cover many aspects of basic research that also have clinical import. The two principal toxins of the clostridial family, Clostridium tetani and C botulinum, are described in detail. The five clinical manifestations of botulism poisoning are also outlined, and structural aspects and the mechanism of action of botulinum toxin are then presented. Finally, the immunologic and pharmacologic principles that define the various serotypes of botulinum toxin are set forth.

Animals↗
PubMed2003

Midfacial rejuvenation via an endoscopic browlift approach: a review of technique.

The middle third of the face has remained a particularly challenging area for facial plastic surgeons to rejuvenate. Many approaches have been advocated, but no one favored technique predominates. The surgical technique of the senior author is reviewed, which has been successfully employed for the past 7 years and which has proven an effective technique in restoring midfacial youth without concomitant lateral-canthal distortion or significant morbidity. The intended objectives of this article are for the reader to understand the specific details of how to perform this technique and the rationale proposed for how a natural midface elevation is achieved by this method.

Endoscopy↗
PubMed2003

Augmentation rhinoplasty of the Asian nose with the "bird" silicone implant.

Augmentation rhinoplasty of the Asian nose has a long legacy of safety in the Orient. The silicone implant design that is proposed resembles a bird in configuration and represents an intermediary form between the traditional I- and L-shaped implants. A pronounced lobular component often poses problems in the nasal tip: This implant exhibits a more diminutive proximal tip segment. Therefore, augmentation of the nasal dorsum and tip can be accomplished safely and successfully with the technique described for carving and inserting the implant. If complications should arise (e.g., infection, extrusion, mobility, or displacement), the implant can be removed simply and quickly because of the capsular formation around the implant. Infection occurred in only 3% of patients in this series and was managed easily with implant removal, oral antibiotics, and reinsertion. Displacement can be addressed with implant removal and reinsertion, and was also observed in 3% of patients. Mobility and extrusion have not been encountered. This technique has proved to be a safe, simple, reliable, and reversible technique in 1,079 rhinoplasties performed during a 10-year period.

Asian People↗
PubMed2002

A philosophy and strategy for surgical hair restoration: a 10-year experience.

BACKGROUND: Three principal strategies have evolved for surgical hair restoration: follicular grafting, scalp reduction, and flap rotation. OBJECTIVE: Although grafting techniques have assumed a preeminent rank as the cornerstone of modern hair-replacement therapy, scalp reduction and rotation methods should not be entirely dismissed. METHODS: Over the past 10 years of clinical experience, the authors have relied on all three methods of hair restoration, carefully tailoring the optimal surgical approach to the patient's expressed concerns and particular regional hair deficit. RESULTS: We have found that scalp reduction and rotation provides a considerable density of hair unmatched by any grafting technique for the vertex and frontotemporal regions, respectively. CONCLUSION: Also we have concluded that the former yields the most natural result for a patient with significant crown baldness who desires hair restoration in that area. However, micro- and minigrafting still represent the overwhelming majority of our operative cases. This article attempts to review the surgical methodology and philosophy that have guided our approach to hair restoration.

Alopecia↗
PubMed2002

Anatomic considerations in aesthetic rhinoplasty.

A thorough understanding of nasal anatomy and physiology remains critical when approaching the nose to correct any contour or functional deficiencies. This article reviews the salient, anatomic features of the nose that are relevant to the rhinoplasty surgeon and further highlights basic surgical techniques that illustrate the anatomy germane to aesthetic surgery. The external anatomy of the nose is discussed in regard to the skin/ soft-tissue envelope, the superficial musculoaponeurtic system/muscular layer, the bony/ cartilaginous framework, and the dynamic tip-support mechanisms. The discussion of internal nasal anatomy concerns functional aspects of the nose, particularly the valvular components and the septum-turbinate complex.

Cartilage↗
PubMed2002

A systematic, graduated approach to rhinoplasty.

Rhinoplasty may be viewed as one of the most technically demanding procedures in facial plastic surgery and requires a level of sophistication derived from diligent study, repetitive execution, and critical review. During the preoperative evaluation, the physician must exercise a systematic approach that includes a thorough investigation into the psychological and physical aspects of the individual patient. A systematic, graduated approach should be undertaken in every rhinoplasty in which the three cornerstones-planning, simplicity, and flexibility-are recalled. Planning entails a thoughtful and critical analysis of what surgical techniques may be best enlisted to achieve the envisioned aesthetic effect. Simplicity argues in favor of performing only those surgical procedures needed to accomplish the task at hand to minimize the variables that arise from protracted, ill-defined surgery. Flexibility implies that the surgeon be capable of modifying his plan if unforeseen operative events disrupt the proposed course of action. All three principles reflect the authors' philosophy about the surgical approach to rhinoplasty, that is, the discretionary use of endonasal (nondelivery and delivery) and external incisions as warranted by circumstance.

Attitude to Health↗
PubMed2002

Computer-aided image-guided endoscopic sinus surgery in unusual cases of sphenoid disease.

The vital neurovascular structures that border the sphenoid sinus make extensive sphenoid sinus surgery hazardous despite the advent of endoscopic sinus surgery (ESS). Computer-aided image-guided endoscopic sinus surgery (CAIGESS) has facilitated safer surgery by providing real-time analysis of complex, three-dimensional anatomic landmarks. We present 6 cases of atypical sphenoid disease, which greatly benefited from the unique superiority of CAIGESS in avoding surgical complications. Two cases of cerebrospinal-fluid (CSF) leak with concomitant meningoencephalocele of the sphenoid sinus were successfully managed with this technique. An inverting papilloma originating from the sphenoid sinus was successfully exenterated using CAIGESS. One patient, who experienced a lateral-rectus muscle palsy from sphenoid sinusitis, underwent successful sinusotomy with CAIGESS. Another patient, who had refractory left-sided sphenoid sinusitis despite 2 ESS procedures, was found to have an obliquely oriented intersinus septum which misled the previous surgeons to enter mistakenly the contralateral sphenoid sinus. CAIGESS allowed accurate identification and removal of the intersinus septum and relief of the sinusitis. Finally, a sphenoid-sinus mucocele that developed after a prior pituitary surgery was safely decompressed with CAIGESS. This surgical approach offers a new and effective adjunct to ESS in selected revision or difficult sinus cases and has proven invaluable in complicated sphenoid cases where the surrounding neurovascular anatomy could otherwise be jeopardized.

Adult↗