Deviation Analyses of Computer-Assisted, Template-Guided Mandibular Reconstruction With Combined Osteotomy and Reconstruction Pre-Shaped Plate Position Technology: A Comparative Study

BackgroundComputer-assisted and template-guided mandibular reconstruction provides higher accuracy and less variation than conventional freehand surgeries. The combined osteotomy and reconstruction pre-shaped plate position (CORPPP) technique is a reliable choice for mandibular reconstruction. This study aimed to evaluate the accuracy of CORPPP-guided fibular flap mandibular reconstruction and analyze the possible causes of the deviations.Patients and MethodsFrom June 2015 to December 2016, 28 patients underwent fibular flap mandibular reconstruction. Virtual planning and personalized CORPPP-guided templates were applied in 15 patients while 13 patients received conventional freehand surgeries. Deviations during mandibulectomy and fibular osteotomy, and overall and triaxial deviation of the corresponding mandibular anatomical landmarks were measured by superimposing the pre- and postoperative virtual models.ResultsThe deviation of the resection line and resection angle was 1.23 ± 0.98 mm and 4.11° ± 2.60°. The actual length of fibula segments was longer than the designed length in 7 cases (mean: 0.35 ± 0.32 mm) and shorter in 22 cases (mean: 1.53 ± 1.19 mm). In patients without ramus reconstruction, deviations of the ipsilateral condylar head point (Co.), gonion point (Go.), and coracoid process point (Cor.) were 6.71 ± 3.42 mm, 5.38 ± 1.71 mm, and 11.05 ± 3.24 mm in the freehand group and 1.73 ± 1.13 mm, 1.86 ± 0.96 mm, and 2.54 ± 0.50 mm in the CORPPP group, respectively, with significant statistical differences (p < 0.05). In patients with ramus reconstruction, deviations of ipsilateral Co. and Go. were 9.79 ± 4.74 mm vs. 3.57 ± 1.62 mm (p < 0.05), and 15.17 ± 6.53 mm vs. 4.36 ± 1.68 mm (p < 0.05) in the freehand group and CORPPP group, respectively.ConclusionMandibular reconstructions employing virtual planning and personalized CORPPP-guided templates show significantly higher predictability, convenience, and accuracy of mandibular reconstruction compared with conventional freehand surgeries. However, more clinical cases were required for further dimensional deviation analysis. The application and exploration of clinical practice would also continuously improve the design of templates.

Biomechanical Stress in Obturator Prostheses: A Systematic Review of Finite Element Studies

Aim. This systematic review is aimed at investigating the biomechanical stress that develops in the maxillofacial prostheses (MFP) and supporting structures and methods to optimize it. Design and Methods. A literature survey was conducted for full-text English articles which used FEA to examine the stress developed in conventional and implant-assisted MFPs from January 2010 to December 2020. Results. 87 articles were screened to get an update on the desired information. 74 were excluded based on a complete screening, and finally, 13 articles were recruited for complete reviewing. Discussion. The MFP is subjected to stress, which is reflected in the form of compressive and tensile strengths. The stress is mainly concentrated the resection line and around the apices of roots of teeth next to the defect. Diversity of designs and techniques were introduced to optimize the stress distribution, such as modification of the clasp design, using materials with different mechanical properties for dentures base and retainer, use of dental (DI) and/or zygomatic implants (ZI), and free flap reconstruction before prosthetic rehabilitation. Conclusion. Using ZI in the defective side of the dentulous maxillary defect and defective and nondefective side of the edentulous maxillary defect was found more advantageous, in terms of compression and tensile stress and retention, when compared with DI and free flap reconstruction.

Super-Selective Intra-Arterial Indocyanine Green Administration for Near-Infrared Fluorescence-Based Positive Staining of Hepatic Segmentation: A Feasibility Study

Background. Despite the increasing number of laparoscopic hepatic procedures for the resection of hepatocellular carcinoma (HCC), intraoperative tumor localization and demarcation remains challenging in comparison to open surgery. In this study, we evaluated the feasibility of positive liver segment staining through the super-selective intra-arterial indocyanine green (ICG) administration. Methods. Eight patients presenting with a single HCC underwent an interventional vascular procedure followed by laparoscopic surgery. A microcatheter was advanced into the hepatic artery branches perfusing the HCC followed by digital subtraction angiography and angiography computed tomography (angio-CT). Patients were then transferred to the operating room, and a laparoscopic hepatectomy was performed under ultrasound guidance. A 5 mL bolus of ICG with a concentration of .125 mg/mL was injected through the microcatheter, and a near-infrared laparoscope was used to detect the fluorescence signal to assess the correspondence between the fluorescence-based demarcation and the intraoperative ultrasound–based demarcation. Results. The duration for the angiography procedure was 32.7 +/− 5.3 min, and it took 242 +/− 118 min from the end of angiography procedure until the start of the surgical procedure. In all cases, the fluorescent liver segment was corresponding to the angio-CT findings. In 6/8 cases, fluorescence imaging was considered helpful in the identification of the resection line. In 3 patients, the resection line was changed according to the positively stained liver segment. Conclusion. We successfully demonstrated the feasibility of the super-selective intra-arterial ICG administration for fluorescence-based positive staining of hepatic segmentation during laparoscopic surgery for HCC (NCT04266548).

Wrapping the pancreas with a polyglycolic acid sheet before stapling reduces the risk of fluid collection on the pancreatic stump after distal pancreatectomy

Background Postoperative pancreatic fistula (POPF) and postoperative fluid collection (POFC) are common complications after distal pancreatectomy (DP). The previous method of reducing the risk of POPF was the application of a polyglycolic acid (PGA) sheet to the pancreatic stump after cutting the pancreas with a stapler (After-stapling); the new method involves wrapping the pancreatic resection line with a PGA sheet before stapling (Before-stapling). The study aimed to compare the incidence of POPF and POFC between two methods. Methods Data of patients who underwent open or laparoscopic DPs by a single surgeon from October 2010 to February 2020 in a tertiary referral hospital were retrospectively analyzed. POPF was defined according to the updated International Study Group of Pancreatic Fistula criteria. POFC was measured by postoperative computed tomography (CT). Results Altogether, 182 patients were enrolled (After-stapling group, n = 138; Before-stapling group, n = 44). Clinicopathologic and intraoperative findings between the two groups were similar. Clinically relevant POPF rates were similar between both groups (4.3% vs. 4.5%, p = 0.989). POFC was significantly lesser in the Before-stapling group on postoperative day 7 (p < 0.001). Conclusions Wrapping the pancreas with PGA sheet before stapling was a simple and effective way to reduce POFC.

Morphological characteristics of dysplasia in the mucous membrane adjacent to the tumor in intestinal type gastric cancer

Introduction. Despite a significant number of publications and a concept known as Correa’s cascade, dysplas-tic processes and the mechanisms of gastric carcinogenesis, are still far from being completely understood. Dysplasia and the processes in the mucous membrane adjacent to the tumor node, their significance, and their role in the field cancerization have also been studied insufficiently. The aim of this work was to analyze the frequency of occurrence and some characteristics of high- and low-grade dysplasia in the gastric mucosa at variable distances from the tumor node. Materials and methods. We carried out a prospective histological study of surgical specimens from 49 patients with intestinal type gastric adenocarcinoma. We studied tissues from the tumor node and adjacent gastric mucosa at various distances from the tumor and assessed the frequency of occurrence and some characteristics of low- and high-grade dysplasia. Results. In the mucous membrane adjacent to the intestinal type adenocarcinoma, 73.5% of cases demon-strated low- and high-grade dysplasia. In all cases, background and precancerous processes were found in areas adjacent to the tumor node with low- and high-grade dysplasia. Conclusion. The incidence of low- and high-grade dysplasia detected in the mucous membrane adjacent to intestinal type gastric adenocarcinoma significantly decreases as the distance from the tumor node in-creases. Dysplastic changes are associated with epithelial hyperplasia, intestinal metaplasia, and inflamma-tory and atrophic changes. The results obtained support field cancerization and highlight the need to study morphological, molecular, and genetic alterations in the gastric mucosa adjacent to the tumor more deeply. The dysplastic changes present at the resection line area indicate that this fact must be considered when determining the resection line. Keywords: gastric cancer, low-grade dysplasia, high-grade dysplasia, epithelial dysplasia, intestinal meta-plasia, inflammatory infiltration, atrophy

Hybrid technique of virtual-assisted lung mapping and systemic indocyanine green injection for extended segmentectomy

Background Various approaches have been used to assist and facilitate segmentectomy with favorable oncological outcomes. We describe a hybrid approach comprising virtual-assisted lung mapping (VAL-MAP), which is a preoperative bronchoscopic dye-marking technique, combined with systemic indocyanine green (ICG) injection. Clinical presentation An asymptomatic 64-year-old man was referred to our department because of a lung nodule detected during his annual medical checkup. The chest computed-tomography image revealed a 16-mm, partly solid, ground-glass nodule in the left segment 4. Because the nodule was hardly palpable and deeply located between the left upper division segment and the left lingular segment, we performed VAL-MAP to facilitate extended left lingulectomy. Five dye markings were undertaken preoperatively. Surgery to remove the nodule was then conducted via complete three-port video-assisted thoracic surgery. The VAL-MAP markings were easily identified intraoperatively and helped locate the nodule. The intersegmental plane was identified by the ICG injection. The resection line was determined based on the intersegmental plane identified by the ICG injection and the site of the nodule suggested by the VAL-MAP markings. Following the resection line, we thoracoscopically achieved extended lingulectomy with sufficient surgical margins. The patient was discharged with no complications. The pathological diagnosis was adenocarcinoma in situ. Conclusion The hybrid technique of VAL-MAP and systemic ICG injection can be useful for accomplishing successful extended segmentectomy.

Comparison of hyperspectral imaging and fluorescence angiography for the determination of the transection margin in colorectal resections—a comparative study

Purpose One relevant aspect for anastomotic leakage in colorectal surgery is blood perfusion of both ends of the anastomosis. The clinical evaluation of this issue is limited, but new methods like fluorescence angiography with indocyanine green or non-invasive and contactless hyperspectral imaging have evolved as objective parameters for perfusion evaluation. Methods In this prospective, non-randomized, open-label and two-arm study, fluorescence angiography and hyperspectral imaging were compared in 32 consecutive patients with each other and with the clinical assessment by the surgeon. After preparation of the bowel and determination of the surgical resection line, the tissue was evaluated with hyperspectral imaging for 5 min before and after cutting the marginal artery and assessed by 6 hyperspectral pictures followed by fluorescence angiography with indocyanine green. Results In 30 of 32 patients, the image data could be evaluated and compared. Both methods provided a comparable borderline between well-perfused and poorly perfused tissue (p = 0.704). In 15 cases, the surgical resection line was shifted to the central position due to the imaging. The border zone was sharper in fluorescence angiography and best assessed 31 s after injection. With hyperspectral imaging, the border zone was visualized wider and with more differences between proximal and distal border. Conclusion Hyperspectral imaging and fluorescence angiography provide similar results in determining the perfusion border. Both methods allow a good and safe visualization of the blood perfusion at the central resection margin to create a well-perfused anastomosis. Trial registration This study was registered at Clinicaltrials.gov (NCT04226781) on January 13, 2020.

LAPAROSCOPIC PELVIC EVISCERATION IN MALE AND FEMALE PATIENTS

treatment of patients with primary and recurrent locally advanced pelvic tumors represents an extremely complex problem of surgical oncology.Aim: to evaluate perioperative and long-term postoperative results of laparoscopic pelvic exenteration technique.Material and methods: in the period from 2011 to 2018, 21 pelvic exenteration was performed with laparoscopic access, (mean age 59.79 ± 8.5), sex distribution: 17 women and 4 men. Nosology distribution: in 6 patients cervical cancer was verified, 7 patients had bladder cancer, 4 patients had rectal cancer, 1 patient had vaginal cancer, 2 patients had recurrence of vaginal cancers after previous uterine extirpation and 1 patient with ovarian neoplasm.Results: the volume of the exenteration was as follows: 9 total, 7 anterior and 5 posterior. In all cases, it was possible to achieve a negative margin of resection line (R0). The duration of the operation, the volume of blood loss, the frequency and nature of intra- and postoperative complications were evaluated.Conclusion: laparoscopic access is accompanied by a smaller amount of blood loss, decrease of frequency of early postoperative complications, contributes to more comfortable postoperative period with early activation, less severe pain syndrome and leads to a reduction in the duration of inpatient treatment.

Local hormonal status of tumor and adjacent tissues in patients with melanoma depending on their gender.

e22084 Background: Gender is an important independent prognostic factor for cutaneous melanoma incidence, and survival in women is better. The purpose of the study was to determine the content of sex steroids and prolactin in tumor, perifocal and resection line tissues in male and female patients with melanoma. Methods: The study included 13 men and 22 women with cutaneous melanoma (M) pT1-2N0M0. Levels of free testosterone (fT), estradiol (E2), estrone (E1), progesterone and prolactin were measured by ELISA in M, perifocal (P) and resection line (RL) tissues after surgical treatment. The average age of patients was in men 54±3.56 years (median age 53, 32-81), in women 65±2.67 years (median age 63, 39-82). Skin tissues obtained from 20 non-cancer patients after plastic surgery served as the control. Results: In M of women, levels of fT, E2 and E1 were elevated on average by 1.3 times, while in men fT was decreased by 1.7 times, and estrogens were increased – E2 by 1.7 and E1 by 3.7 times, compared to the corresponding control levels. In women, fT in P tissues was increased by 1.6 times, while parameters in RL were similar to control values. In men, fT in P and RL tissues was decreased by 3.8 and 2.3 times respectively, and E2 was increased by 1.6 and 1.3 times respectively. E1 in P tissues was decreased by 1.7 times, in RL – similar to control levels. Conclusions: M in patients of both genders has an altered hormonal profile characterized by hyperestrogenia, with the prevalence of E1 and androgen deficiency in men. The expansion of the “tumor field” due to changes in the hormonal profile of P and even RL tissues was established only in male patients with the same morphological prevalence of the process, which may be one of the reasons for the more aggressive tumor course.