Abstract
Background: Inguinal lymphadenectomy (ILND) has historically been associated with substantial morbidity. The objective of this study was to obtain contemporary ILND morbidity rates and to identify potentially preventable risk factors.
Methods: We carried out a retrospective review of medical records for all superficial, deep, and combination groin dissections performed at a single, high-volume academic centre between January 2007 and December 2020. We collected data points for patient, disease, and surgery characteristics, and cancer outcomes. The outcome of interest was any complication within 30 days of surgery. Complications included wound infection, wound necrosis or disruption, seroma, drainage procedure, hematoma, and lymphedema. We performed multivariate logistic regression using SAS version 9.4.
Results: We identified 139 patients having undergone 89 superficial, 12 deep, and 38 combined dissection types, respectively. Melanoma accounted for 84.9% of cases. Of these patients, 56.1% had an adverse postoperative event within 30 days. Increasing age (odds ratio [OR] 1.04, 95% confidence interval [CI] 1.01–1.07, p < 0.01) and number of positive lymph nodes harvested (OR 1.22, 95% CI 1.00–1.50, p = 0.05) were associated with more complications. Patients with deep dissection showed a lower likelihood of complications than those with superficial dissection (OR 0.15, 95% CI 0.03–0.84, p < 0.05).
Conclusion: Complication rates after ILND remain high. We identified a number of risk factors, providing opportunities for better selection and prevention.
Inguinal lymphadenectomy (ILND) is a surgical procedure used for the management of regionally advanced or recurrent malignancies such as melanoma. 1,2 It is classified into different types, based on Ploeg’s definitions. 1 Superficial dissection includes removing all the tissue and lymph nodes in the inguinofemoral area, extending to the apex of the femoral triangle and deep to the fascia lata, with skeletonization of the vessels. Deep dissection involves the removal of all the tissues running along the inguinofemoral and the deep iliac vessels up to the common iliac. In some cases, the superficial and deep dissection procedures are combined. These operations have historically been associated with a high risk of morbidity that affects the patient’s quality of life.3–10 Negative postoperative outcomes include both acute and chronic complications. Adverse events such as wound infection, seroma, skin necrosis, flap complications, or wound dehiscence5–7 often lead to extended hospital stays, delayed return to normal activities, and reduced quality of life.2,8–10
The frequency of superficial, deep, and combined dissection procedures has steadily decreased owing to the advent of less invasive techniques such as sentinel lymph node biopsy (SLNB)11–13 and, more recently, because of selective dissection protocols such as the second Multicenter Selective Lymphadenectomy Trial (MSLT-2).12,14 Furthermore, the development of systemic treatment options, such as targeted therapy and immunotherapy, has resulted in a super-selection of more complex patients or those with treatment failure being directed to surgery. As a result, there are fewer opportunities to improve surgical outcomes, reduce adverse events, and ensure optimal training.
The aim of this study was to identify risk factors for adverse events after ILND. By obtaining a contemporary rate of early postoperative complications and associated risk factors, we can identify possible targets for improvement of surgical outcomes. A better ability to assess the risk of adverse events offers the potential to develop perioperative strategies that can decrease their incidence.
Methods
We performed a retrospective review of all patients who underwent ILND between January 2007 and December 2020 at the McGill University Health Centre, a tertiary surgical oncology referral centre located in Montréal, Canada. After securing institutional research ethics board approval, we queried the hospital operative database to identify all cases of superficial, deep, and combined dissection procedures performed by surgical oncologists. We excluded patients who had undergone concurrent popliteal dissection. In addition to collecting clinical follow-up data, 2 trained clinicians collected the following variables for each case: patient characteristics (sex, date of birth, smoking history, history of diabetes, height, weight, body mass index [BMI], hypothyroidism, history of radiation therapy), disease information (primary tumour characteristics [i.e., location, histology, thickness, mitosis, ulceration, lympho-vascular invasion, regression, perineural invasion, BRAF]); surgical technique details (site, date of surgery, presentation, indication, use of prophylactic antibiotics, use of antithrombotic prophylactic, use of a sequential compression device [SCD], performing surgeon, dissection type, incision type, use of sartorius flap, operative time, presence of intraoperative complications, blood loss, Foley placement, postoperative compressive bandaging, drainage, duration of immobilization, use of postoperative antibiotics, total length of hospital stay, total lymph nodes harvested, and total positive lymph nodes harvested), and perioperative care (wound infection, signs of wound necrosis, use of wound care services, drainage procedure, signs of hematoma, lymph edema, lymphorrhea, date of drain removal, other complications, emergency department postoperative admission, use of neoadjuvant therapy, use of adjuvant systematic treatment, use of adjuvant radiotherapy, patient status, and date of recurrence). The outcome of interest was the occurrence of an adverse event within 30 postoperative days, categorized as part of 1 of the following groups: wound infection, wound necrosis or dehiscence, seroma, hematoma, and lymphedema. We defined a wound infection as any clinical symptom of infection such as erythema, warmth, or notable discharge at the surgical wound requiring treatment with antibiotics or drainage. We included infected seromas in this category. We defined wound necrosis as necrotic edges of the wound that necessitated secondary wound healing for closure and wound dehiscence as a partial or complete separation of the layers of the wound. We defined seroma as the occurrence of a swelling or collection of fluctuating fluid in the inguinal area, whether or not a drainage procedure was performed. Last, we defined lymphoedema as any swelling of the involved limb reported as a clinical observation.
We used frequencies and percentages for description of patient and group characteristics. Selection of potential predictors for analysis was based on the quality of data for each variable and the cohort size. We assessed association of variables with early complications by univariate and multivariable logistic regression analyses models using SAS version 9.4 (SAS Institute Inc.). The final model included sex, age, diabetes, indication, dissection type, total number of lymph nodes harvested, and total number of malignant lymph nodes harvested.
Results
A total of 141 ILNDs were performed during the study period. Of these, we excluded 2 owing to limited access to data. Key patient and disease characteristics are shown in Table 1. Of the 139 procedures, 81 (58.2%) were performed on females. Mean patient age at surgery was 59 years for females (standard deviation [SD] 16.2) and 62 years for males (SD 16.5). Most patients did not smoke or have diabetes or a documented history of cardiovascular disease, hypothyroidism, or receiving radiation therapy to the groin area.
Most surgeries (84.9%) were performed for a diagnosis of melanoma. The second most frequent diagnosis was sarcoma (8.6%). Less frequent pathologies included neuroendocrine carcinoma, squamous cell carcinoma, and Merkel cell carcinoma. Most lymphadenectomies were performed for recurrent disease (61.1%), most often clinically evident (56.8%) versus radiologically evident only (19.4%). About a quarter of cases (23.7%) were operated for microscopiconly disease (sentinel lymph node–positive).
Key procedure-related characteristics are shown in Table 2. Of the 139 lymphadenectomies, 64% were superficial dissections, 8.6% were deep dissections, and 27.3% were combined superficial and deep dissections. Prophylactic antibiotic and antithrombotic use were documented in 66.9% and 61.9% of operative records, respectively. A sequential compression device was applied in 61.9% of patients, and a Foley catheter was inserted in 60.4%. Mean operative time (measured from incision time to application of dressing) was 172.6 minutes, 235.6 minutes, and 307.8 minutes for superficial, deep, and combined dissections, respectively. Of the 139 patients, 49.4% had a sartorius flap while 28.5% did not, and 22.5% had missing information. Mean blood loss was 75.8 mL for all procedures, and an intraoperative complication was noted in only 1.4% of patients. At the end of the procedure, a drain was left in 75.5% of patients, with 56.1%, 18.7%, and 0.7% having 1, 2, or 3 drains, respectively. According to medical order timestamps, postsurgical immobilization lasted an average of 9.9 hours, including the recovery room stay. The mean number of total lymph nodes harvested was 11 of all procedure types, and the mean number of positive lymph nodes harvested was 2. Of all records, 5.7% needed home care services during the 30 days after surgery.
The frequency of any complication reported was 65.2%, 16.7%, and 50.0% for superficial, deep, and combined dissections, respectively (Table 3). When stratified by type of cancer, 55.9% of all melanoma, 50.0% of sarcoma, and 77.8% of other patients reported the occurrence of any postoperative complication. The 2 most common complications were wound infections (26.6%) and seromas (26.6%); 5.76% of patients had a wound disruption. Of the 37 patients with a seroma, 83.8% required a drainage procedure. The median number of drainage procedures was 2. Only 2 patients (1.4%) developed a hematoma. Clinically evident lymphoedema was recorded within 30 postoperative days in 34 patients (24.5%). Overall, 5.76% of patients required home care services to manage a postoperative complication and 16.6% returned to the emergency department during the 30-day postoperative period.
Stratifying by procedure type, we observed a slightly higher adverse outcome rate among patients who underwent a superficial dissection through a transverse incision. However, incision type was not reported in 29.2% (n = 26) of patients with superficial dissection, and 34.6% of those with missing information also had complications. With respect to deep dissection, we did not perform stratification by incision type owing to small sample size (n = 12).
After assessing distribution of data, we omitted variables with disproportionate categories or high rates of missing data from modelling analyses (e.g., previous radiation therapy). We performed univariate analysis with available reliable data (Table 4). Multivariate analysis presented age, dissection type, and number of positive lymph nodes as statistically significant predictors of complications (Table 5). For every year increase in the patient’s age, the odds of a complication increased by 3.8% (OR 1.04, 95% CI 1.01–1.07, p < 0.01). Deep dissections were associated with lower complication rates than superficial dissections and combined lymphadenectomies. Deep dissection procedures show 84.7% lower odds of having complications than superficial dissection (OR 0.15, 95% CI 0.03–0.84, p < 0.05).
Finally, malignant nodal yield was shown to affect adverse events; for every additional positive lymph node dissected, the risk of a 30-day complication increases by 22.4% (OR 1.22, 95% CI 1.00–1.50, p < 0.05).
Discussion
Inguinal lymphadenectomy is the operation of choice in many cancers. However, it is a complex procedure, historically associated with a high risk of substantial postoperative morbidity, which affects both quality of life and survival. 15 The management of regional lymph nodes in cancer has evolved substantially over the past 2 decades. For instance, in melanoma, systematic ILND has been replaced by SLNB, an operation with much less risk of morbidity.12,13,16 In addition, sentinel nodes that harbour only micrometastatic disease are now followed clinically, with a completion dissection offered only to those who develop clinical or radiologic disease.12,14,16 These achievements have deferred ILND to much more aggressive, clinically palpable disease or subsequent relapse. With fewer of the more complex cases being directed to dissection, opportunities to achieve adequate training for these complex procedures and to optimize surgical outcomes have also decreased substantially. The advent of effective systemic therapy further reinforces the need for a reassessment of the impact of these surgeries as postoperative complications inevitably delay access to treatment.17 There is also evidence showing that complications are associated with significant implication for earlier cancer recurrence and death.18,19 Past ILND studies have been limited by small sample sizes, with most ranging from 50 to 120 patients.8,15,20 We therefore performed this study in a large cohort of patients undergoing ILND to determine the factors affecting early postoperative complication rate and to identify potential opportunities for innovative protocols to improve surgical outcomes. Similarly to other smaller series, we observed a high rate of complications (56.1%) in patients within 30 days of undergoing superficial, deep, or combined dissection for cancer.21–23
In this series, age was a statistically significant predictor of an early postoperative complication. With 60% of all cancers occurring in patients older than 65 years, a “grey storm” is expected in oncologic services.24–26 Innovative approaches toward patient selection and preparation may provide an opportunity to intervene and mitigate against negative outcomes. For example, in other complex surgical procedures, prehabilitation is recognized as a new approach to cancer care, with emphasis on preoperative care that tackles goals to improve physical activity, nutritional intake, and psychological well-being as a means of optimizing surgical outcomes.27–29 Studies provide evidence of prehabilitation as an effective intervention in reducing postoperative morbidity in older patients undergoing surgery for colorectal, liver, and pancreatic malignancies.30–33 To our knowledge, there are no prehabilitation protocols designed for complex ILND; this gap in care represents an interesting avenue for research. Findings of newly published clinical trials in locally advanced melanoma support the use of neoadjuvant therapy.34,35 Authors identified the positive effects of introducing protocols that focused on patient knowledge to include proactive care (i.e., wound care treatment and early recognition of wound complications).36,37 As integration of neoadjuvant therapy into melanoma treatment plans gains popularity, there is opportunity to develop prehabilitation and patient education interventions during extended preoperative periods. With the recognition that not all older patients present the same risk level, a multidimensional frailty score system would help to identify those with lower physiologic reserve who have a greater chance of postoperative morbidity.38–40 Few studies have looked at these types of tools in the surgical treatment planning of cutaneous malignancies.41,42 The FRAIL (Fatigue, Resistance, Ambulation, Illnesses, a Loss of Weight) score, validated by Morley and colleagues, is an example of a clinical decision support tool that accurately identifies patients who would benefit most from prehabilitation. 43 It has been used in nonmelanoma skin pathologies and presents itself as a reliable predictive tool for postoperative outcomes.42,44
Type of dissection carries considerable weight on the risk of complications, disfigurement, and mortality.45–47 Previously published literature presents contradictory results; some studies report similar complication rates while others show higher odds of complication among those with deep dissection. Dasmahapatra and colleagues found no difference in complication or lymphedema rate between the 2 operations.2 Spillane and colleagues reported the same.48 Conversely, James found higher odds of complication in deep dissection patients.49 Our findings diverged, with lower odds of complications for deep dissection than superficial dissection. We speculate that these findings are a result of small sample sizes across the literature. In fact, the average number of reported cases in published literature is less than 100, whereas we report a series of 139.
In our study, we observed that for every additional positive lymph node dissected, the risk of complication increased in a statistically significant manner. Patients with greater burden of disease tend to require more aggressive dissections, often yielding higher numbers of lymph nodes harvested.50 However, with respect to palpable lymphadenopathy, our data did not show any difference in complication incidence. This is similar to a recent mixed-methods study, complemented with a retrospective review and semi-structured interviews reporting no significant differences concerning perioperative outcomes including postoperative complications.51 Promising research is emerging concerning the use of neoadjuvant therapy (immunotherapy and targeted therapy) with high rates of pathologic complete response.52 Although it is not yet the standard of care for stage III melanomas, these studies suggest the important role of presurgical therapy in potentially reducing disease burden in bulky clinical disease, thereby decreasing postoperative complications. Restricted access to operating rooms during the COVID-19 pandemic resulted in increased use of preoperative systemic therapy, with good results. Nevertheless, longer follow-up is required to validate the impact on cancer-specific outcomes.52
Limitations
This study has several limitations. The infrequency of the procedure resulted in a relatively small sample size. That being said, our study has a larger number of procedures than older publications, most of which report on fewer than 100 patients. In addition, we were limited to data documented in medical records, which tend to be inconsistent in availability and detail (e.g., BMI). This remains a common challenge in retrospective chart audits, making some statistical correlations impossible. Despite these limitations, we have shown that the rate of complications after groin lymphadenectomy remains high. We have identified opportunities for future multisite, collaborative research, including prospective standardized data collection and quality improvement interventions for the care of patients undergoing inguinal lymph node dissection. This surgery carries high risk of complications; meticulous patient selection, preoperative planning, and optimization, in addition to presurgical systemic treatment to downstage the disease burden, may help to minimize the morbidity of ILND.
Conclusion
Early postoperative complication rates after ILND remain high. A number of risk factors were identified, providing opportunities for better case selection and prevention.
Footnotes
This work was presented at the Canadian Society of Surgical Oncology, Apr. 29, 2022, Toronto, Ont. (short presentation); the American Association of Clinical Oncology Annual Meeting, June 3–7, 2022, Chicago, Ill. (poster), Abstract e21531; and the 41st Congress of the European Society of Surgical Oncology, Oct. 19–21, 2022, Bordeaux, France (poster).
Competing interests: Ari Meguerditchian reports serving as secretary and treasurer of the Canadian Society of Surgical Oncology, and scientific director, St.Mary’s Research Centre. No other competing interests were declared.
Contributors: All authors designed the study and acquired and analyzed the data. All authors wrote the manuscript and revised it critically for important intellectual content. All authors gave final approval of the version to be published and agreed to be accountable for all aspects of the work.
- Accepted November 9, 2023.
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