Minimally Invasive Surgery for Superficial Organs in Oncology - A Review

Introduction

Advances and adaptation of technology over the last few decades have led to a variety of minimally invasive procedures being performed for the superficial organ malignancies. Gagner's¹ first description of endoscopic subtotal parathyroidectomy in 1996 heralded the era of minimal invasive surgeries for the superficial organ diseases. Robotic surgeries soon followed suit after FDA approval of da Vinci robotic systems for the head and neck surgeries in 2009. Since then the scope of minimally invasive surgeries for superficial organs has been continuously expanding to include the malignancies. In superficial organ malignancies, minimally invasive techniques have been applied for thyroid, inguinal lymph nodes, neck dissection and breast, so far, with majority of the techniques described for thyroid. The robotic system with its enhanced dexterity and degree of freedom along with three-dimensional visualization is seen to be an efficient alternative.² These approaches were developed to minimize postoperative pain, improve cosmetic results, and potentially reduce the length of hospital stay. However, longer operating times, need for additional surgical equipment, and steep learning curves remain as disadvantages.³

This article briefly highlights and reviews the various minimally invasive techniques described and employed for superficial organ malignancies.

Minimally Invasive Surgery (MIS) in Thyroid

Kocher was awarded Nobel prize for his extensive work on thyroid surgery. The commonly used incision for thyroidectomy today is a modification of Kocher's original incision of 8 to 10 cm. Thyroid surgery has come a long way since then and has grown in leaps and bounds. Thyroidectomies in oncology are generally indicated for the differentiated thyroid malignancies which include papillary and follicular thyroid cancers, medullary thyroid cancers. There are various surgical approaches for thyroidectomy other than conventional open technique. It was in the late 1990s that minimally invasive techniques for thyroidectomy were introduced. Consequently, various gas and gasless techniques have been developed. It was Gagner's (1996)¹ first description of endoscopic subtotal parathyroidectomy that has led to the adaptation of technology for thyroidectomies. Two such approaches are the minimally invasive open thyroidectomy (MIT) and the minimally invasive videoassisted thyroidectomy (MIVAT). The MIVAT technique uses a 1.5 cm skin crease incision and is shown to be associated with less postoperative pain, decreased length of stay, and less surgical complications than open thyroidectomy.⁴ Despite these advantages, a scar though small remains in the aesthetically relevant part of body. To overcome the scar in neck, many extra cervical approaches were developed where the incisions are placed in chest, breast and axilla. Transoral and post auricular approaches have also been described. Ohgami et al., (2000)⁵ demonstrated the anterior/breast approach in a series of five patients. This approach has been found to be feasible and safe for resection of thyroid nodules.⁶ Since its description, this technique has enjoyed considerable attention and can be safely performed for well differentiated thyroid carcinomas with a volume of less than 100 gm and the only contraindications included previous history of neck surgeries, thyroiditis. Similarly an axillary approach as described by Ikeda et al.,⁷ uses an axillary 30 mm incision which gets concealed by the arms, providing the main advantage of better cosmetic outcome. Technical difficulties in dissecting the contralateral lobe of the thyroid gland and narrow operating space, 'sword-fighting' are potential disadvantages of the axillary approach.⁸

Further modifications to the above approaches have led to the development of endoscopic hybrid approaches like axillary bilateral- breast approach (ABBA) and bilateral axillo-breast approach (BABA). Shimazu et al.,⁹ argued that ABBA achieved better cosmesis, allowed a better view and reduced interference from surgical instruments, thus avoiding the “sword fighting”. BABA technique, a modification of ABBA by Choe et al.,¹⁰ reported similar advantages of better cosmesis and visualization. Transoral thyroid surgery was first performed by Wilhelm in 2010,¹¹ achieving a complete scar less approach. Here, port incisions are made in the vestibule/sublingual region. However, its role in oncological surgeries is limited as it is indicated only in papillary microcarcinoma without lymph node metastasis. Few preliminary reports of lymph nodal dissection through the trans oral route do exist.¹²

Robotic surgeries have followed suit. Robotic transoral and axillary approaches have been described. Professor Chung and his team described and propagated the robotic transaxillary approach.¹³ Nayak SP et al.,¹⁴ in our institute have defined a new technique of performing robotic thyroidectomy called robotic assisted breastaxilloinsufflation thyroidectomy (RABIT). RABIT involves the use of the da Vinci Xi robotic system with CO2 gas insufflation using five ports. Patient is positioned supine with neck extension, both the arms then extended and rotated cephalad. Incision about 1.5 to 2 cm is marked in the anterior axillary fold on the side of the lesion and the flap is raised between the pectoral fascia and muscle, up to midline and beyond. Contralateral axillary and breast incisions are made. Working space is inflated with CO2 at a pressure of 10 mm. Preliminary data suggest that RABIT is a safe and effective technique for patients desiring scar free thyroidectomy. The surgeons have an advantage of better vision and single docking for total thyroidectomy. Also, initial experience suggests that this technique is safe for node positive differentiated thyroid cancers. RABIT technique has several advantages over BABA RT such as smaller breast incision with minimal trauma, use of monopolar scissors and most importantly enbloc removal of specimen without having to divide it as in BABA RT.

The use of surgical robots has provided a newer approach to performing minimally invasive thyroid surgery, overcoming the limitations of endoscopic approaches. However more validation studies are required to standardize the robotic procedures. Superior visualization, greater dexterity and precision tissue dissection are no doubt the greatest advantages of robotic surgery, but longer operating time remains the chief drawback.

MIS in Neck

Comprehensive neck dissection (CND) has been the standard procedure for the management of neck in head and neck malignancies for decades. It is considered to be safe and has lower risk of regional recurrences. Despite this, post-operative morbidity and shoulder dysfunction are common occurrences. Minimally invasive neck dissection (MIND) can overcome the disadvantages of CND and provide advantages in terms of efficacy, safety and cosmetic benefits.^15,16 After the advancement in endoscopic techniques and FDA approval of da Vinci system for head and neck cancer surgery in 2009, the advantages of this minimally invasive approaches have been extensively utilized.

Many descriptions of endoscopic and robotic MIND have been found. Majority of the endoscopic and robotic techniques described so far have had a modified facelift or the retroauricular approach. Kim et al.,¹⁷ described retroauricular approach for endoscopic neck dissection using a self-retaining retractor for good visualization of the surgical field.

Byeon et al.,¹⁸ also reported neck dissections with similar approach, highlighting the advantages of robotic surgery compared with endoscopic surgery. It was stressed that the wrist articulated movement of the robotic system provided an edge over the endoscopic techniques in the narrow working space of the neck. However higher costs associated with robotic surgery precludes its wide acceptability. Likewise, many authors have reported the robotic technique with the similar modified face-lift or the retroauricular approach.^16,18-20 In all the above mentioned approaches, both endoscopic and robotic, it can be noted that the scar still lies in the neck, even though it is posterior and merging with the hairline. To overcome this, Nayak SP et al.,²¹ described a technique of MIND using standard laparoscopic equipment. Here the port placements were done below the clavicle completely away from the neck area, along with CO2 insufflation for working space creation. Nayak SP et al.,²² in their retrospective data of 45 patients evaluated the feasibility of MIND on clinically node negative oral cancer cases. They found that MIND is aesthetically better than conventional procedures for oral cancer patients due to its safety, efficacy and reproducibility at any centre using the standard laparoscopic equipment. It is worthwhile to note here that this procedure does not require any other special device or retractors as in postauricular approach. As robots are expensive and hard to obtain, the technique can be used to treat patients who are unable to afford or access robot-assisted surgery.

Overall MIND provides better functional and cosmetic results without compromising on oncological effectiveness and produces an aesthetically acceptable scar. Minimally invasive techniques have several advantages like smaller incisions, lesser risk of infection, decreased pain and hospital stay with better scar satisfaction for patients.

MIS for Inguinal Lymph Node Dissection

For years, inguinal lymphadenectomy (IL) has been the standard of care for patients with tumors originating from lower limb and trunk, including melanoma and genitourinary neoplasms (vulvar and penile cancers),²³ and it has been linked to significant improvement in survial.²⁴ However, morbidity due to flap necrosis, infections and seroma formations affect patients’ quality of life.^25,26

To overcome these complications, many minimally invasive techniques for IL have been attempted. One such technique is a three-port approach named video endoscopic inguinal lymphadenectomy (VEIL). VEIL was first described for penile cancer and was known to eliminate skin complications associated with open IL.²⁷ Later, Xu et al.,²⁸ demonstrated veil for vulvar cancer.

At present VEIL technique utilizes midthigh three port approach. A modification of which, using three lateral incisions has been practiced in our institute and it was found that lateral VEIL (l-VEIL) can provide better surgical outcomes including nodal yield compared to open IL.²⁹ Another advantage of this lateral approach is its ergonomic superiority compared to the standard veil technique where camera port is placed along the long axis of thigh, working ports on either sides.²⁹

Overall in comparison to open IL, VEIL requires smaller incisions, has higher healing rate and provides better cosmetic effect.³⁰

There are few preliminary reports of robotic-assisted inguinal lymph node dissection (RAILND) by Dogra PN et al.,³¹ suggesting that RAILND is efficacious, with minimal morbidity. However, further larger studies are required to fine tune the procedure and validate its efficacy.

Conclusion

To conclude, minimally invasive surgeries for superficial organ malignancies is gradually gaining strong foothold since the past decade. Many novel endoscopic and robotic techniques are being described, opening a myriad of possibilities for their application in malignancies. Overall, minimally invasive techniques are found to be safe and feasible with smaller incisions, lesser risk of infection, decreased pain and hospital stay with better scar satisfaction for patients.

However, increased duration of surgery, high cost in case of robotic surgeries and learning curves are few drawbacks.

Conflicts of Interests

Nil