A 1:1 matched comparison of posterior retroperitoneal and lateral transabdominal adrenalectomy using a robotic platform.

BACKGROUND: Posterior retroperitoneal adrenalectomy is considered less invasive compared with lateral transperitoneal counterpart. There is controversy in the literature about how the two approaches compare regarding perioperative outcomes. Moreover, no studies have compared both approaches while incorporating the use of a robotic platform. The aim of this study was to compare the outcomes of robotic posterior retroperitoneal adrenalectomy and lateral transperitoneal adrenalectomy using a 1:1 matched propensity analysis. METHODS: Patients who underwent robotic posterior retroperitoneal adrenalectomy were matched 1:1 to patients who underwent robotic lateral transperitoneal adrenalectomy between 2008 and 2022 at a single center. Matching factors included diagnosis, tumor size, Gerota's fascia-to-skin distance, and perinephric fat thickness. Perioperative outcomes were compared between groups using the χ2 analysis and Wilcoxon Rank Sum test. RESULTS: A total of 511 robotic adrenalectomies were performed during the study period, of which 77 patients in each group were matched. There was no difference between posterior retroperitoneal adrenalectomy and lateral transperitoneal adrenalectomy groups, respectively, in terms of operative time (134 vs 128 min, P = .64), conversion to open (0% vs 0%, P = .99), pain level on a postoperative day 1 (visual analog scale 5 vs 6, P = .14), morphine milligram equivalents used (18 vs 20 morphine milligram equivalents /day, P = .72), length of stay (1 vs 1 day, P = .48), and 90-day complications (2.6% vs 3.9%, P = .65). Estimated blood loss for posterior retroperitoneal adrenalectomy was statistically lower (5 vs 10 mL, P = .001) but not considered to be clinically significant. CONCLUSION: Perioperative outcomes of lateral transperitoneal adrenalectomy, including those related to recovery, were similar to those of posterior retroperitoneal adrenalectomy when matched for tumor and patient anthropometric parameters.

Laparoscopic versus robotic lateral transabdominal adrenalectomy.

BACKGROUND AND OBJECTIVES: Despite an increased adaptation of robotic adrenalectomy, its advantages over laparoscopic adrenalectomy (LA) have not been defined. The aim of the study was to compare perioperative outcomes of robotic versus laparoscopic lateral transabdominal adrenalectomy using a large single-center experience. METHODS: This was a retrospective single center study. Within 22 years, patients who underwent laparoscopic and robotic transabdominal lateral adrenalectomy were identified from a prospective institutional review board-approved database. Clinical and perioperative outcomes were compared using Mann-Whitney U and χ2  tests. RESULTS: There were 190 patients who underwent laparoscopic and 281 patients who underwent robotic transabdominal lateral adrenalectomy. The groups were comparable except for a higher percentage of female patients in the robotic group. For robotic versus LA, operative time and hospital stay were shorter, in addition to less blood loss, conversion to open and margin positivity, for pheochromocytoma and malignant tumors. Morbidity rates were similar between the two groups. CONCLUSIONS: Despite the limitations of a retrospective design, this large study demonstrates significant advantages of robotic versus laparoscopic transabdominal lateral adrenalectomy in terms of perioperative outcomes and margin clearance.

Comparison of incidental parathyroid tissue detection rates on pathology after total thyroidectomy performed with or without near-infrared autofluorescence imaging.

BACKGROUND: Near-infrared autofluorescence imaging is an adjunct to parathyroid identification. As it does not show perfusion, it is important to study its impact during thyroidectomy by measuring quantifiable data on parathyroid detection rather than function. The aim of this study was to compare incidental parathyroidectomy rates in patients undergoing total thyroidectomy with or without near-infrared autofluorescence. METHODS: Retrospective study of patients who underwent total thyroidectomy between 2014 and 2022 at one center. Clinical parameters, including rates of incidental parathyroid tissue on pathology reports, were compared between near-infrared autofluorescence and non-near-infrared autofluorescence groups. Near-infrared autofluorescence was used to guide dissection (identification) and/or to confirm tissue as parathyroid (confirmation). Statistical analysis was done with Wilcoxon rank sum test and χ2 analysis. RESULTS: There were 300 patients in the near-infrared autofluorescence and 750 patients in the non-near-infrared autofluorescence group. The rate of incidental parathyroid tissue detection on final pathology was 13.3% (n = 40) in the near-infrared autofluorescence and 23.2% (n = 174) in the non-near-infrared autofluorescence group (P < .001). The rate of incidental parathyroid tissue detected on pathology with near-infrared autofluorescence decreased when used for identification and confirmation of parathyroid tissue (30.0% to 13.4%, P < .001), but not when used for confirmation only (19.6% to 18.5%, P = .89). Impact of near-infra red autofluorescence in decreasing the rate of incidental parathyroid tissue was more profound for early (38.5% to 17.1%) versus mid-late career surgeons (20% to 13%). CONCLUSION: Our results suggest that the use of near-infrared autofluorescence may help decrease the rate of incidental parathyroid tissue detected on final pathology if used for both identification and confirmation of parathyroid glands during thyroidectomy.

Characterization of indocyanine green fluorescence imaging patterns of pheochromocytomas.

BACKGROUND: Indocyanine green (ICG) fluorescence is a new intraoperative imaging modality for adrenal tumors. Previous work suggested that pheochromocytomas did not show fluorescence, but experience is limited. The objective of this study is to analyze fluorescence imaging patterns of pheochromocytomas. METHODS: This was an IRB-approved retrospective study. Patients who underwent adrenalectomy with ICG imaging were identified from a departmental database. Intraoperative fluorescence patterns were analyzed by reviewing surgical videos. Descriptive and comparative statistical analyses were performed to determine factors associated with different fluorescence patterns of pheochromocytomas. RESULTS: Of the 46 pheochromocytomas included, 50% (n = 23) exhibited fluorescence. Parameters predicting fluorescence on univariate analysis were age, tumor size and hereditary. On multivariate analysis, tumor size was the only predictive parameter of ICG fluorescence, with loss of fluorescence at a threshold of > 3.2 cm (p = 0.004). CONCLUSIONS: This is the largest cohort to date assessing fluorescence properties of pheochromocytomas. In contrast to previous studies, we demonstrated that smaller pheochromocytomas do exhibit fluorescence. This may support the application of intraoperative ICG imaging for smaller or bilateral pheochromocytomas, which may assist in identification and/or cortical-sparing during adrenalectomy.

A multicenter evaluation of near-infrared autofluorescence imaging of parathyroid glands in thyroid and parathyroid surgery.

BACKGROUND: The usefulness of incorporating near-infrared autofluorescence into the surgical workflow of endocrine surgeons is unclear. Our aim was to develop a prospective registry and gather expert opinion on appropriate use of this technology. METHODS: This was a prospective multicenter collaborative study of patients undergoing thyroidectomy and parathyroidectomy at 7 academic centers. A questionnaire was disseminated among 24 participating surgeons. RESULTS: Overall, 827 thyroidectomy and parathyroidectomy procedures were entered into registry: 42% of surgeons found near-infrared autofluorescence useful in identifying parathyroid glands before they became apparent; 67% correlated near-infrared autofluorescence pattern to normal and abnormal glands; 38% of surgeons used near-infrared autofluorescence, rather than frozen section, to confirm parathyroid tissue; and 87% and 78% of surgeons reported near-infrared autofluorescence did not improve the success rate after parathyroidectomy or the ability to find ectopic glands, respectively. During thyroidectomy, 66% of surgeons routinely used near-infrared autofluorescence to rule out inadvertent parathyroidectomy. However, only 36% and 45% felt near-infrared autofluorescence decreased inadvertent parathyroidectomy rates and improved ability to preserve parathyroid glands during central neck dissections, respectively. CONCLUSION: This survey study identified areas of greatest potential use for near-infrared autofluorescence, which can form the basis of future objective trials to document the usefulness of this technology.

Laparoscopic versus robotic adrenalectomy in severely obese patients.

BACKGROUND: Over the last 20 years, the prevalence of severe obesity (body mass index ≥ 35 kg/m2) has almost doubled. This condition increases the challenge of laparoscopic adrenalectomy (LA) by creating problems with instrument reach, adequate exposure, and visualization. The aim was to compare perioperative outcomes of laparoscopic versus robotic adrenalectomy (RA) in severely obese patients. METHODS: This was an institutional review board-approved retrospective study. Prospectively collected clinical parameters of patients who underwent LA versus RA between 2000 and 2021 at a single center were compared using Mann-Whitney U, ANOVA, Chi-square, and multivariate regression analysis. Continuous data are expressed as median (interquartile range). RESULTS: For lateral transabdominal (LT) adrenalectomies, skin-to-skin operative time (OT) [164.5 (71.0) vs 198.8 (117.0) minutes, p = 0.006] and estimated blood loss [26.2 (15.0) vs 72.6 (50.0) ml, p = 0.010] were less in RA versus LA group, respectively. Positive margin rate, hospital stay and 90-day morbidity were similar between the groups (p = NS). For posterior retroperitoneal (PR) approach, operative time and perioperative outcomes were similar between LA and RA groups. Multivariate analysis demonstrated robotic versus laparoscopic technique (p = 0.006) to be an independent predictor of a shorter OT. CONCLUSION: There was a benefit of robotic over the laparoscopic LT adrenalectomy regarding OT and estimated blood loss. Although limited by the small sample size, there was no difference regarding perioperative outcomes between RA and LA performed through a PR approach.

The utility of near infrared autofluorescence imaging for detecting small bowel carcinoid tumors in comparison to DOTATATE PET: A pilot study.

BACKGROUND: Small bowel carcinoid (SBC) primary tumors can be multifocal in 40%-55% of patients and challenging to detect. Near infrared autofluorescence (NIRAF) is used for detection of parathyroid glands. It is unknown if this technology can be used to identify SBCs and how it would compare with current imaging modalities. METHODS: This was a prospective institutional review board-approved pilot study of three patients undergoing resection of SBCs. NIRAF was used to image SBCs and mesenteric lymph nodes intraoperatively and at back table. Findings were compared with preoperative imaging, surgical exploration and pathology. Statistics were performed using Mann-Whitney U test. RESULTS: Eleven SBCs and 12 mesenteric lymph nodes were analyzed. All SBCs had a brighter focal autofluorescence (AF) signal compared to background. Normalized pixel intensity of SBCs was 2.2 (0.7) and normal small bowel 1.4 (0.6) (p < 0.0001). NIRAF was less accurate in detecting occult lymph node metastasis, but was superior to DOTATATE PET for detecting SBCs in two of three patients. CONCLUSIONS: This preliminary report suggests that SBCs exhibit distinctly bright AF signals on NIRAF to create a contrast distinction from normal small bowel. This technology may have a utility as an adjunctive tool for intraoperative detection of occult SBCs.

Laparoscopic versus robotic adrenalectomy in pheochromocytoma patients.

BACKGROUND AND OBJECTIVES: Pheochromocytoma is a challenging tumor type requiring resection with a clear margin and an intact capsule to prevent recurrences. Our aim was to compare perioperative outcomes of laparoscopic adrenalectomy (LA) versus robotic adrenalectomy (RA) for pheochromocytoma. METHODS: In an institutional review board-approved retrospective study, clinical parameters of patients who underwent LA versus RA at a single center were compared using Mann-Whitney U, χ2 , and survival analyses. Continuous data are expressed as median (interquartile range). RESULTS: There was a total of 157 patients (RA: n = 87, LA: n = 70) analyzed. Estimated blood loss (36.3 [35.0] vs. 99.9 [65.0] cc, p = 0.020) and hospital stay (1.3 [0.0] vs. 2.2 [1.0] days, p = 0.010) were lower in robotic versus laparoscopic group, respectively. Disease-free and overall survival was similar between groups. The rate of conversion to open for tumors ≥5 cm was less in the robotic group (0% vs. 14%, respectively, p = 0.048). CONCLUSION: In this study, long-term outcomes of LA and RA were similar, although adrenalectomies performed robotically were associated with less blood loss, shorter hospital stay, and a lower chance of conversion to open in the case of large tumors.

A visual deep learning model to predict abnormal versus normal parathyroid glands using intraoperative autofluorescence signals.

BACKGROUND: Previous work demonstrated that abnormal versus normal parathyroid glands (PGs) exhibit different patterns of autofluorescence, with former appearing darker and more heterogenous. Our objective was to develop a visual artificial intelligence model using intraoperative autofluorescence signals to predict whether a PG is abnormal (hypersecreting and/or hypercellular) or normal before excision during surgical exploration for primary hyperparathyroidism. METHODS: A total of 906 intraoperative parathyroid autofluorescence images of 303 patients undergoing parathyroidectomy/thyroidectomy were used to develop model. Autofluorescence image of each PG was uploaded into the visual artificial intelligence platform as abnormal or normal. For deep learning, randomly chosen 80% of data was used for training, 10% for testing, 10% for validation. The area under the receiver operating characteristic (AUROC), area under the precision-recall curve (AUPRC), recall (sensitivity), and precision (positive predictive value) of the model were calculated. RESULTS: AUROC and AUPRC of the model to predict normal and abnormal PGs were 0.90 and 0.93, respectively. Recall and precision of the model were 89% each. CONCLUSION: Visual artificial intelligence platforms may be used to compare the autofluorescence signal of a given parathyroid gland against a large database. This may be a new adjunctive tool for intraoperative assessment of parathyroid glands during surgical exploration for primary hyperparathyroidism.

A Visual Deep Learning Model to Localize Parathyroid-Specific Autofluorescence on Near-Infrared Imaging : Localization of Parathyroid Autofluorescence with Deep Learning.

BACKGROUND AND PURPOSE: Parathyroid glands may be detected by their autofluorescence on near-infrared imaging. Nevertheless, recognition of parathyroid-specific autofluorescence requires a learning curve, with other unrelated bright signals causing confusion. The aim of this study was to find out whether machine learning could be used to facilitate identification of parathyroid-specific autofluorescence signals on intraoperative near-infrared images in patients undergoing thyroidectomy and parathyroidectomy procedures. METHODS: In an institutional review board-approved study, intraoperative near-infrared images of patients who underwent thyroidectomy and/or parathyroidectomy procedures within a year were used to develop an artificial intelligence model. Parathyroid-specific autofluorescence signals were marked with rectangles on intraoperative near-infrared still images and used for training a deep learning model. A randomly chosen 80% of the data were used for training, 10% for testing, and 10% for validation. Precision and recall of the model were calculated. RESULTS: A total of 466 intraoperative near-infrared images of 197 patients who underwent thyroidectomy and/or parathyroidectomy procedures were analyzed. Procedures included total thyroidectomy in 54 patients, thyroid lobectomy in 24 patients, parathyroidectomy in 108 patients, and combined thyroidectomy and parathyroidectomy procedures in 11 patients. The overall recall and precision of the model were 90.5 and 95.7%, respectively. CONCLUSIONS: To our knowledge, this is the first study that describes the use of artificial intelligence tools to assist in recognition of parathyroid-specific autofluorescence signals on near-infrared imaging. The model developed may have utility in facilitating training and decreasing the learning curve associated with the use of this technology.

Detection of near-infrared autofluorescence from adrenal neoplasms: An initial experience.

BACKGROUND AND OBJECTIVES: Fluorescence from adrenal tumors can be detected with near-infrared imaging after injection with indocyanine green. However, it is unknown if adrenal tumors exhibit autofluorescence. The aim of this study was to determine whether adrenal tumors emit near-infrared autofluorescence (NIRAF). METHODS: This was a prospective study of patients who underwent minimally invasive adrenalectomy at a tertiary center. Intraoperative images were analyzed to detect NIRAF with a 750 nm camera. Descriptive and comparative statistical analyses were performed. RESULTS: Twenty-five adrenalectomies were examined. Only 11 tumors (44%), that originated from the cortex exhibited autofluorescence. A contrast distinction between the tumor and retroperitoneum was observed in 23 patients, whereas a contrast distinction between the tumor and normal adrenocortical tissue was seen in 12 patients. The overall fluorescence intensity of adrenal tumors was found to be variable and ranging between 0.3 and 5.6 times that of the background tissue. Pheochromocytoma, malignancy and adrenal cyst did not demonstrate NIRAF. CONCLUSION: This is the first study to show that adrenocortical tissue can demonstrate NIRAF. The pattern of fluorescence was similar to that observed after indocyanine green injection in our historical experience. NIRAF has a potential to be used as an intraoperative optical adjunct during adrenalectomy.

The efficacy of laparoscopic transversus abdominis plane block on reducing postoperative narcotic usage in patients undergoing minimally invasive adrenalectomy.

BACKGROUND: Post-operative pain relief after abdominal operations is critical for patient satisfaction and rapid recovery. Narcotics have been a traditional part of postoperative analgesia, with transversus abdominis plane (TAP) block introduced recently. The aim of this study is to assess the efficacy of laparoscopic TAP block on postoperative pain control in patients undergoing minimally invasive adrenalectomy. METHODS: This was an institutional review board-approved retrospective study. Parameters related to postoperative pain control were compared between patients who underwent robotic transabdominal lateral adrenalectomy with (after December 2018) or without laparoscopic TAP block (control group) (before December 2018) by one surgeon. Statistics were performed using Mann Whitney U and Chi-square tests. RESULTS: There were 86 patients in the TAP and 83 patients in the control group. Groups were similar regarding demographic and clinical parameters. Despite the availability of intravenous acetaminophen to a higher percentage of patients in the control (31.3%) versus the TAP group (8.1%), 0-24 h lowest postoperative pain scores were significantly lower in the TAP group (P < 0.0001). In TAP versus control group, percentage of patients requiring narcotics and amount of narcotics used was lower (P = 0.04 vs P = 0.0004, respectively). Mainly due to less pain-related over-stay, percentage of patients requiring more than a day of hospital stay was less in the TAP (12%) versus control group (18%) (P = 0.01). CONCLUSION: To our knowledge, the utility of TAP block in patients undergoing minimally invasive adrenalectomy has not been reported in the past. This study shows that there may be benefits of laparoscopic TAP block in reducing post-operative narcotic usage while improving pain control in these patients.

Comparison of Parathyroid Autofluorescence Signals in Different Types of Hyperparathyroidism.

BACKGROUND: There are scant data in the literature regarding whether parathyroid autofluorescence (AF) signal patterns vary based on the etiology of hyperparathyroidism. The aim of this study was to compare AF signals of parathyroid glands across different etiologies of hyperparathyroidism. METHODS: As a prospective institutional review board-approved study between 2016 and 2019, AF intensities and heterogeneity indexes (HIs) of parathyroid glands in patients who underwent parathyroidectomy using AF were calculated and compared using Chi-square, Kruskal Wallis, Mann Whitney U, and logistic regression tests. RESULTS: Of the total of 183 patients, 127 patients had sporadic classic primary hyperparathyroidism, 30 patients had sporadic normohormonal primary hyperparathyroidism, 10 patients had sporadic normocalcemic primary hyperparathyroidism, 12 patients had tertiary hyperparathyroidism, and 4 patients had familial primary hyperparathyroidism related to multiple endocrine neoplasia (MEN) 2A. There were no statistical differences in AF signals of abnormal parathyroid glands in classic, normohormonal or normocalcemic sporadic hyperparathyroidism. Parathyroid glands in patients with tertiary hyperparathyroidism were similar in intensity, but more homogenous compared to those in sporadic primary hyperparathyroidism. CONCLUSIONS: The pattern of AF exhibited by abnormal parathyroid glands was similar across different spectrums of primary hyperparathyroidism, in accordance with observations in the literature. However, parathyroid glands in tertiary hyperparathyroidism were more homogeneous, despite exhibiting a similar intensity of AF compared to those in sporadic primary hyperparathyroidism. These differences should be kept in mind when using the AF pattern as an adjunct to visual assessment in parathyroid exploration.