Bora Kahramangil

The use of near-infrared fluorescence imaging in endocrine surgical procedures

Near‐infrared fluorescence imaging in endocrine surgery is a new, yet highly investigated area. It involves indocyanine green use as well as parathyroid autofluorescence. Several groups have described their technique and reported on the observed utility. However, there is no consensus on technical details. Furthermore, the correlation between intraoperative findings and postoperative outcomes is unclear. With this study, we aim to review the current literature on fluorescence imaging and share our insights on technical details.

Local recurrence after microwave thermosphere ablation of malignant liver tumors: results of a surgical series

Background. Microwave thermosphere ablation is a new treatment modality that creates spherical ablation zones using a single antenna. This study aims to analyze local recurrence associated with this new treatment modality in patients with malignant liver tumors. Methods. This is a prospective clinical study of patients who underwent microwave thermosphere ablation of malignant liver tumors between September 2014 and March 2017. Clinical, operative, and oncologic parameters were analyzed using Kaplan‐Meier survival and Cox proportional hazards model. Results. One hundred patients underwent 301 ablations. Ablations were performed laparoscopically in 87 and open in 13 patients. Pathology included neuroendocrine liver metastasis (n = 115), colorectal liver metastasis (n = 100), hepatocellular cancer (n = 21), and other tumor types (n = 65). Ninety‐day morbidity was 7% with one not procedure‐related mortality. Median follow‐up was 16 months with 65% of patients completing at least 12 months of follow‐up. The rate of local tumor recurrence rate per lesion was 6.6% (20/301). Local tumor, new hepatic, and extrahepatic recurrences were detected in 15%, 40%, and 40% of patients, respectively. Local recurrence rate per pathology was 12% for both colorectal liver metastasis (12/100) and other metastatic tumors (8/65). No local recurrence was observed to date in the neuroendocrine liver metastasis and in the limited number of patients with hepatocellular cancers. Tumor size >3 cm and tumor type were independent predictors of local recurrence. Conclusion. This is the first study to analyze local recurrence after microwave thermosphere ablation of malignant liver tumors. Short‐term local tumor control rate compares favorably with that reported for radiofrequency and other microwave technologies in the literature.

Robotic and endoscopic transoral thyroidectomy: feasibility and description of the technique in the cadaveric model

Background Numerous new approaches have been described over the years to improve the cosmetic outcomes of thyroid surgery. Transoral approach is a new technique that aims to achieve superior cosmetic outcomes by concealing the incision in the oral cavity. Methods Transoral thyroidectomy through vestibular approach was performed in two institutions on cadaveric models. Procedure was performed endoscopically in one institution, while the robotic technique was utilized at the other. Results Transoral thyroidectomy was successfully performed at both institutions with robotic and endoscopic techniques. All vital structures were identified and preserved. Conclusions Transoral thyroidectomy has been performed in animal and cadaveric models, as well as in some clinical studies. Our initial experience indicates the feasibility of this approach. More clinical studies are required to elucidate its full utility.

Efficacy of surgeon-performed, ultrasound-guided lymph node fine needle aspiration in patients with thyroid pathologic conditions

Background: Although the concept of surgeon‐performed fine needle aspiration of thyroid nodules is established, experience with surgeon‐performed lymph node fine needle aspiration is scant. We aimed to study the efficacy of surgeon‐performed lymph node fine needle aspiration in patients with thyroid pathologic conditions. Methods: This is an institutional review board–approved study of patients with thyroid pathologic conditions who underwent surgeon‐performed lymph node fine needle aspiration between 2002 and 2017. Efficacy and utility were analyzed. Results: A total of 201 patients with benign nodular goiter (n=30) and thyroid cancer (n=200) underwent 230 lymph node fine needle aspirations (89 during preoperative workup, 141 at postoperative follow‐up). Insufficient aspiration rate was 6% and indeterminate cytologic results 3%. In 91% of patients with suspicious lymph nodes, definite diagnosis could be obtained by fine needle aspiration; 51% (n=118) of fine needle aspirations indicated metastasis from thyroid cancer and 40% (n=91) benign findings. Sensitivity and specificity of lymph node fine needle aspiration in diagnosing nodal metastasis were 92% and 89%, respectively. Cytologic testing and thyroglobulin washout indicated 95% concordance. On logistic regression, spherical shape, microcalcifications, cystic appearance, and loss of hilum on ultrasound independently predicted lymph node metastasis. Conclusion: Our data indicate that an adequate surgeon‐performed lymph node fine needle aspiration is highly accurate in diagnosing nodal status in thyroid pathologic conditions. We recommend adoption of this technique, when feasible, to develop an efficient, comprehensive thyroid practice.

Heterogeneous and low-intensity parathyroid autofluorescence: Patterns suggesting hyperfunction at parathyroid exploration

Background: Although parathyroid glands have been found to exhibit autofluorescence with near‐infrared fluorescence imaging, it is unknown if autofluorescence characteristics vary between hyperfunctioning and normofunctioning glands. The hypothesis was that pattern of autofluorescence exhibited by hyperfunctioning versus normofunctioning parathyroid glands would be different. Methods: This is an Institutional Review Board–approved, prospective clinical study. Patients underwent bilateral neck exploration for primary hyperparathyroidism, during which autofluorescence from each gland was assessed with near‐infrared fluorescence imaging. Pattern and intensity of autofluorescence between hyperfunctioning and normofunctioning parathyroid glands were compared. Results: Overall, 199 parathyroid glands were identified in 50 patients (single gland disease, n = 31; multigland disease, n = 19). Autofluorescence was detected from 96% (n = 192) of parathyroid glands, all of which exhibited a higher intensity autofluorescence than the background tissues. Parathyroid gland location was revealed by near‐infrared fluorescence imaging before dissection in 26% (n = 52). A total of 77 glands that were large or firm were excised and 122 were preserved because of normal appearance. Hyperfunctioning parathyroid glands had a lower mean normalized autofluorescence intensity than normofunctioning parathyroid glands (1.8, and 2.6, respectively, P < .001). Moreover, hyperfunctioning parathyroid glands more often exhibited a heterogeneous pattern of autofluorescence (75% and 5%, respectively, P < .001). On multivariate analysis, only parathyroid gland hyperfunction correlated with normalized autofluorescence intensity. On receiver operative characteristic curve, optimal cutoff of normalized autofluorescence intensity to differentiate hyperfunctioning from normofunctioning parathyroid glands was 2.0. Conclusion: Our results indicate that hyperfunctioning and normofunctioning parathyroid glands exhibit different patterns of autofluorescence in hyperparathyroidism. Given these findings, autofluorescence pattern could be implemented as another adjunctive parameter for gland assessment during parathyroid exploration.

Characterization of fluorescence patterns exhibited by different adrenal tumors: Determining the indications for indocyanine green use in adrenalectomy

Background A number of small studies have reported the use of indocyanine green imaging during adrenalectomy. Nevertheless, imaging properties of different tumors and the indications for indocyanine green imaging use in adrenalectomy have not been defined. Methods This is an Institutional Review Board–approved retrospective review of a prospectively maintained database. Consenting patients underwent indocyanine green imaging fluorescence–guided robotic adrenalectomy. Fluorescence patterns of adrenal tumors were assessed. Multivariate logistic regression was performed to determine the best clinical applications. Results One hundred patients with Cushing syndrome (n = 29), pheochromocytoma (n = 24), primary hyperaldosteronism (n = 23), nonsecreting adrenocortical adenoma (n = 9), and other tumors (n = 15) underwent robotic adrenalectomy through lateral transabdominal (n = 77) and posterior retroperitoneal (n = 23) approaches. Mean tumor size was 3.6 cm and mean body mass index 33. A total of 74% of the tumors were hyperfluorescent compared with the surrounding retroperitoneal tissues, whereas the remaining 26% were nonfluorescent. Hyperfluorescence was predicted by adrenocortical tissue origin but not by demographic characteristics or tumor size. The contrast distinction between the tumor and the retroperitoneum was better, similar, or inferior on indocyanine green fluoresced compared with the nonfluoresced view in 41%, 27%, and 32% of patients, respectively. The utility was best for adrenocortical adenomas removed through a lateral transabdominal approach. Indocyanine green fluorescence imaging was used to confirm remnant viability in all 4 patients undergoing cortical‐sparing adrenalectomy for pheochromocytoma (n = 2), adrenal cyst (n = 1), and lymphatic malformation (n = 1). Conclusion Adrenal tumors have different patterns of indocyanine green fluorescence based on histologic origin. Indocyanine green confers the highest utility for adrenocortical tumors removed through a lateral transabdominal approach and cortical‐sparing adrenalectomy.

Analysis of postoperative biochemical values and clinical outcomes after adrenalectomy for primary aldosteronism

Background. Primary aldosteronism causes hypertension and hypokalemia and is often surgically treatable. Diagnosis includes elevated plasma aldosterone, suppressed plasma renin activity, and elevated aldosterone renin ratio. Adrenalectomy improves hypertension and hypokalemia. Postoperative plasma aldosterone and plasma renin activity may be useful in documenting cure or failure. Method. A retrospective analysis of patients who underwent adrenalectomy for primary aldosteronism from 2010 to 2016 was performed, analyzing preoperative and postoperative plasma aldosterone, plasma renin activity, hypertension, and hypokalemia. The utility of postoperative testing was assessed. Clinical cure was defined as improved hypertension control and resolution of potassium loss. Biochemical cure was defined as aldosterone renin ratio reduction to <23.6. Results. Forty‐four patients were included; 20 had plasma aldosterone and plasma renin activity checked on postoperative day 1. In the study, 40/44 (91%) were clinically cured. All clinical failures had of biochemical failure at follow‐up. Postoperative day 1aldosterone renin ratio <23.6 had PPV of 95% for clinical cure. Cured patients had mean plasma aldosterone drop of 33.1 ng/dL on postoperative day 1; noncured patient experienced 3.9 ng/dL increase. A cutoff of plasma aldosterone decrease of 10 ng/dL had high positive predictive value for clinical cure. Conclusion. Changes in plasma aldosterone and plasma renin activity after adrenalectomy correlate with improved hypertension and hypokalemia. The biochemical impact of adrenalectomy manifests as early as postoperative day 1. We propose a plasma aldosterone decrease of 10 ng/dL as a criterion to predict clinical cure.

Comparison of indocyanine green fluorescence and parathyroid autofluorescence imaging in the identification of parathyroid glands during thyroidectomy

Background Indocyanine green fluorescence (ICGF) and parathyroid autofluorescence (AF) are two new techniques that aid in the identification of parathyroid glands (PG) intraoperatively during thyroidectomy. There is no study comparing the efficacy of these techniques. Methods This was an IRB-approved clinical study comparing the utility of ICGF and AF for identification of PGs during thyroidectomy. Data were collected prospectively. Both techniques were compared to naked eye (NE) for PG detection. Standard statistical methods were used for data analysis. Results Twenty-two patients in each group underwent a total of 39 total thyroidectomies and 5 thyroid lobectomies. AF and ICGF had similar detection rates for PGs [98% (61 of 62) and 95% (60 of 63) of PGs, respectively; P=0.31]. The location of PGs was suggested before detection with NE more frequently by AF than ICGF [52% (32 of 62) vs. 6% (4 of 63) of PGs; P<0.001]. In 82% (18 of 22) of patients at least one PG was detected by AF before NE, as opposed to 14% (3 of 22) by ICGF (P<0.001). The median (range) number of PGs detected before NE per patient was greater with AF than ICGF [2 (0-3) vs. 0 (0-2)];. Upper PGs were more likely to be detected by AF before recognition with NE than the lower ones (P=0.03). There was no predictive factor for ICGF detection. Postoperative hypocalcemia rates were similar [9% (2 of 22) and 5% (1 of 22) for AF and ICGF, respectively; P>0.99]. Conclusions To the best of our knowledge, this is the first comparative study between parathyroid AF and ICGF in detection of PGs during thyroidectomy. Our data suggest both techniques have similarly high detection rates and that the main difference lies in the timing of detection. AF more frequently detects PGs before recognition with NE compared to ICGF.

Laparoscopic versus open 1-stage resection of synchronous liver metastases and primary colorectal cancer

BACKGROUND The aim of this study is to compare the perioperative and oncologic outcomes of open and laparoscopic approaches for concomitant resection of synchronous colorectal cancer and liver metastases. METHODS Between 2006 and 2015, all patients undergoing combined resection of primary colorectal cancer and liver metastases were included in the study (n=43). Laparoscopic and open groups were compared regarding clinical, perioperative and oncologic outcomes. RESULTS There were 29 patients in the open group and 14 patients in the laparoscopic group. The groups were similar regarding demographics, comorbidities, histopathological characteristics of the primary tumor and liver metastases. Postoperative complication rate (44.8% vs. 7.1%, P=0.016) was higher, and hospital stay (10 vs. 6.4 days, P=0.001) longer in the open compared to the laparoscopic group. Overall survival (OS) was comparable between the groups (P=0.10); whereas, disease-free survival (DFS) was longer in laparoscopic group (P=0.02). CONCLUSIONS According to the results, in patients, whose primary colorectal cancer and metastatic liver disease was amenable to a minimally invasive resection, a concomitant laparoscopic approach resulted in less morbidity without compromising oncologic outcomes. This suggests that a laparoscopic approach may be considered in appropriate patients by surgeons with experience in both advanced laparoscopic liver and colorectal techniques.