Robotic Mohs Surgery for Precise Skin-Sparing Excision

Abstract

Robotic Mohs surgery represents a significant advancement in the field of dermatologic oncology, offering high-precision, skin-sparing excision for complex cutaneous malignancies. With the integration of robotics into the classic Mohs micrographic technique, clinicians can achieve superior margin control, minimize healthy tissue loss, and potentially improve both oncologic and cosmetic outcomes. This article provides a comprehensive review of the scientific basis, clinical utility, and evolving evidence supporting the use of robotic-assisted Mohs surgery. Current guidelines, recent technological advances, and practical considerations for implementation in clinical practice are critically discussed, offering insights for dermatologic surgeons and multidisciplinary care teams.

Introduction

Mohs micrographic surgery (MMS) has long been established as the gold standard for the treatment of high-risk and recurrent non-melanoma skin cancers (NMSC), particularly basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Traditional Mohs relies on meticulous excision and immediate histopathological mapping to ensure complete tumor removal while sparing uninvolved tissue. The advent of robotic technology in surgery has begun to transform numerous surgical disciplines, providing enhanced dexterity, stability, and visualization. Robotic Mohs surgery merges these attributes with the established oncologic principles of MMS, aiming to further refine margin control and tissue preservation. This review examines the role of robotic platforms in Mohs surgery, emphasizing scientific mechanisms, clinical implications, and the current state of research.

Epidemiology / Disease Burden

Non-melanoma skin cancer remains the most prevalent malignancy worldwide, with incidence rates continuing to rise due to factors such as increased UV exposure, aging populations, and improved surveillance. The global burden is substantial, with millions of new cases of BCC and SCC diagnosed annually. While most NMSCs are curable, recurrent or high-risk lesions—particularly those located in cosmetically and functionally sensitive areas—pose significant clinical challenges. The need for precise margin control and maximal tissue preservation is paramount, particularly in the face, scalp, and periocular regions, where excessive excision may result in significant morbidity.

Pathophysiology

BCC and SCC arise from the basal and squamous layers of the epidermis, respectively, driven by cumulative genetic mutations often induced by ultraviolet radiation. Tumor growth typically displays irregular, finger-like extensions beyond clinically visible margins, complicating complete excision. Mohs micrographic surgery addresses this by enabling real-time histological assessment of the entire peripheral and deep margins. However, traditional manual techniques may be limited by human factors such as hand tremor or variability in tissue handling, potentially affecting precision. Robotic assistance leverages fine motor control and consistent movement patterns to reduce these limitations, enhancing the fidelity of excision along complex tumor borders.

Risk Factors

Major risk factors for NMSC include chronic sun exposure, fair skin phenotype, immunosuppression (e.g., solid organ transplant recipients), prior history of skin cancer, chronic inflammatory skin conditions, and genetic syndromes such as xeroderma pigmentosum. High-risk anatomical sites—such as the nose, eyelids, ears, and lips—warrant special consideration due to their critical functional and aesthetic importance. Tumors with aggressive histologic subtypes, perineural invasion, or recurrent disease are also at increased risk for incomplete excision, making precise, tissue-sparing techniques especially relevant in these populations.

Clinical Features

Clinically, BCC and SCC present as slowly enlarging plaques or nodules, often with telangiectasia, ulceration, or induration. Lesions located in high-risk zones may exhibit indistinct borders, necessitating careful preoperative mapping. The primary goal of Mohs surgery is complete tumor eradication with maximal sparing of healthy tissue—an objective that is particularly challenging when tumor margins are ill-defined or when prior treatments have altered normal tissue planes. Robotic assistance can facilitate more accurate and reproducible excisions in these scenarios, with potential for improved functional and cosmetic outcomes.

Diagnosis

Diagnosis of NMSC is confirmed histopathologically following biopsy. Preoperative assessment includes careful clinical and dermatoscopic examination, high-frequency ultrasound or confocal microscopy in selected cases, and thorough mapping of the lesion's extent. For Mohs candidates, intraoperative frozen section analysis provides definitive margin status. Robotic systems can be integrated with imaging modalities and digital mapping tools, allowing for precise planning and execution of excisions and potentially reducing operator-dependent variability in specimen orientation and processing.

Treatment & Management

The standard treatment for high-risk NMSC is Mohs micrographic surgery, which combines stepwise excision with immediate microscopic evaluation of margins. Robotic-assisted Mohs surgery utilizes advanced robotic platforms—such as articulated arms, enhanced visualization systems, and haptic feedback—to perform delicate excisions with sub-millimeter accuracy. This technology allows surgeons to navigate complex anatomical contours and achieve consistent, controlled resections around irregular tumor borders. In addition to improving margin control, robotic systems may reduce procedure time, operator fatigue, and intraoperative tissue trauma. Postoperative management remains unchanged, with wound repair tailored to defect size, location, and patient-specific factors.

Recent Advances / Emerging Therapies

Recent years have witnessed the integration of artificial intelligence (AI) and machine learning algorithms with robotic Mohs platforms, enabling real-time tissue recognition and automated margin assessment. Digital pathology and augmented reality overlays can assist surgeons in visualizing residual tumor foci and planning subsequent stages of excision. Miniaturized robotic instruments and tele-operated systems are under investigation for remote or minimally invasive Mohs procedures. Early clinical studies suggest that robotic assistance can reduce positive margin rates and improve cosmetic results, particularly for complex or recurrent NMSC. Ongoing trials are evaluating long-term outcomes, patient satisfaction, and cost-effectiveness of these novel approaches.

Guideline Recommendations

Current clinical guidelines from leading dermatological societies continue to endorse Mohs micrographic surgery as the preferred approach for high-risk NMSC and tumors in anatomically sensitive locations. While specific recommendations regarding robotic Mohs surgery are still evolving, expert consensus recognizes the potential of robotic platforms to enhance precision and reproducibility. As technology matures and evidence accumulates, formal guideline updates are anticipated to incorporate robotic assistance for selected indications, particularly where conventional techniques are limited by anatomical or technical complexity. Multidisciplinary collaboration and ongoing outcomes research will be essential to define best practices and integration pathways for robotic Mohs surgery.

Conclusion

Robotic Mohs surgery marks a promising frontier in the management of complex cutaneous malignancies, offering enhanced precision, tissue conservation, and potentially superior functional and cosmetic outcomes. While early evidence supports its feasibility and clinical utility, larger studies and long-term data are needed to validate its advantages over traditional approaches. Integration of robotics with advanced imaging and AI algorithms holds promise for further optimization of margin control and workflow efficiency. As the field continues to evolve, robotic-assisted Mohs surgery is poised to become a valuable tool in the armamentarium of dermatologic oncology, particularly for high-risk, anatomically challenging, and recurrent skin cancers.