A laparoscopic odyssey: Managing giant colonic lipoma-induced colo-colonic intussusception - A case report.

INTRODUCTION: Colonic lipomas (CL) are rare non-epithelial benign tumors. Giant Colonic lipomas (>4 cm) can cause serious complications such as bowel obstruction, massive bleeding, perforation, and intussusception. Early diagnosis is difficult and preoperative discrimination between malignant lesions and large cl is challenging. Surgical resection is the cornerstone of the treatment. CASE PRESENTATION: A 57-year-old woman presented to our surgical department complaining about intermittent crampy abdominal pain with an alternation of diarrhea and constipation for the last 7 months. After radiological and endoscopic investigations, the diagnosis of colo-colonic intussusception caused by colonic lipoma was confirmed. The patient underwent laparoscopic enucleation and a histopathological examination of the specimen confirmed the diagnosis of colonic lipoma. DISCUSSION: Colonic lipomas (CL), though rare (0.2 to 4 %), are the third most common benign colon tumors. Typically affecting adult women (57 %), these non-epithelial growths can vary in size from 2 mm to 30 cm, often remaining asymptomatic until complications arise. Colonic lipomas may lead to intussusception or bowel obstruction, with clinical presentation depending on size and location. Diagnosis relies on abdominal CT scans or MRI, while treatment options include surveillance, endoscopic, or surgical resection. Laparoscopic approaches offer favorable postoperative outcomes, although precise localization remains a challenge. Endoscopic techniques are limited, particularly for larger or difficult-to-access lipomas, necessitating expert care. CONCLUSION: Giant colonic lipoma can cause colonic intussusception leading to emergency operation. We think that laparoscopic enucleation seems to be the ideal treatment choice, especially when the malignancy cannot be excluded.

Beyond the surface: Does stage I-II endometriosis impact fertility? Exploring the challenges of mild disease.

Endometriosis is one of the most common gynecologic conditions that women face throughout their lives. Despite advances in technology, diagnosis and treatment of this relapsing and remitting condition is still challenging for many women. This review focuses on literature pertaining to minimal/mild (stage I/II) endometriosis and its impact on fertility. The effectiveness of medical interventions to improve infertility and obstetric outcomes in both natural and assisted reproductive technologies cycles remains debated. The recent ESHRE guidelines suggests that operative laparoscopy could be considered for rASRM stage I/II endometriosis as it improves ongoing pregnancy rates.

Anatomical outcomes and complications of sacrocolpopexy using Surelift Uplift mesh: A multicentric observational study.

OBJECTIVE: The study evaluated the anatomical and functional outcomes, as well as the safety data of laparoscopic sacrocolpopexy (LSC) for pelvic organ prolapse (POP) using a lightweight macroporous mesh. METHODS: A multicentric observational study was developed including five expert centers between March 2011 and December 2019. Inclusion criteria were female patients with symptomatic ≥stage II POP (POP-Q classification), who underwent a LSC. A lightweight and macroporous mesh device (Surelift Uplift) was used. Baseline anatomical positions were evaluated using POP-Q stage. The anatomical outcomes and procedural complications were assessed during the postoperative period. Primary outcomes were anatomical success, defined as POP-Q stage ≤I, and subjective success, defined as no bothersome bulge symptoms, and no repeat surgery or pessary use for recurrent prolapse. RESULTS: A total of 325 LSCs were analyzed with a median patient age of 66 (interquartile range [IQR] 61-73). After a median follow-up of 68 months (IQR 46.5-89), anatomical success was found in 88.9%, whereas subjective success was seen in 98.5% of the patients. Recurrent prolapse presented as cystocele (1.5%). Reported complications were bladder (4.6%) or rectum lesions (0.6%), de novo urinary incontinence (12.9%), and mesh extrusion (1.2%). CONCLUSIONS: LSC provides significant clinical improvement and excellent anatomical results, with a low risk of serious complications for women with ≥2 grade POP in a real clinical practice setting.

Subserosal pregnancy: Systematic review with proposal of new diagnostic criteria and ectopic pregnancy classification.

Ectopic pregnancy (EP) is a pregnancy where the growing blastocyst implants outside the endometrial cavity. EP account approximately for 0.5-1% of all pregnancies, and extrauterine implant is the leading cause of woman mortality in the first trimester of gestation. Non-tubal pregnancies (NTP) account for less than 5% of all EP. NTP are accompanied by a 7-8 times higher risk of maternal mortality when compared to tubal pregnancies, and their treatment might sometimes be very challenging. Subserosal pregnancy (SP) has been defined as rare variant of intramural pregnancy, where a portion of the gestational sac was surrounded only by the serosa of the uterus. Whereas the treatment of the ectopic pregnancies is crucial for patients' lives and for adequate fertility sparing and considering the need for surgical treatment in many cases, an early diagnosis is important; thus we believe it g might be useful to define some criteria to guide subserosal pregnancy identification, and to distinguish it from other types of non-tubal ectopic pregnancy. A systematic review on Pubmed, Scopus, Web of Science and Google Scholar was performed. Case reports, randomized controlled trials, prospective controlled studies, prospective cohort studies, retrospective studies, and case series were considered eligible. In all databases mentioned were considered manuscripts published from 1990 up to March 2023. Only four articles were eligible for inclusion in this review. All patients underwent to surgical management in laparoscopy. The main risk factors for this type of ectopic pregnancy were previous uterine surgery with opening of the endometrial cavity and assisted reproductive techniques procedures. Considering our results, we propose new classification and diagnostic criteria for subserosal pregnancy, to distinguish it from other types of non-tubal ectopic pregnancies with the aim to preserve fertility following the most correct management.

Effect of dexmedetomidine on pulmonary function in obese patients undergoing laparoscopic surgery.

OBJECTIVE: This research aimed to ascertain the effect of dexmedetomidine on pulmonary function in obese patients undergoing laparoscopic surgery. METHODS: Obese patients undergoing laparoscopic surgery under general anesthesia were separated into the control group (group C) and the dexmedetomidine group (group D) (n = 30). Patients in group D were infused with dexmedetomidine (1 µg/kg) intravenously for 10 min and then at a rate of 0.5 mg/kg h until 30 min before the end of the surgery, and those in group C were infused with an equal volume of saline. The surgery time points were divided into: before anesthesia induction (T0), 5 min after intubation (T1), 30 min after pneumoperitoneum (T2), 10 min after pneumoperitoneum release (T3), at the time of extubation (T4), 3 min after extubation (T5), and 24 h after surgery (T6). Arterial blood was collected for blood gas analysis to record arterial partial pressure of oxygen (PaO2) and arterial partial pressure of carbon dioxide (PaCO2). Dynamic lung compliance (Cdyn), oxygenation index (OI), alveolar-arterial oxygen partial pressure difference (A-aDO2), and respiratory index (RI) were calculated. The time of surgery, anesthesia, CO2 pneumoperitoneum, eye-opening, and time from the end of surgery to extubation were recorded. Plasma IL-8 and IL-10 levels were measured from T0 to T6. RESULTS: The time of surgery, anesthesia, CO2 pneumoperitoneum, eye-opening, and time from the end of surgery to extubation in group D were not statistically significant when compared with those in group C. Versus at the T1 time point, A-aDO2 and RI were higher and Cdyn and OI were lower in both groups at T2 and T3 time points. Versus group C, group D had higher Cdyn and OI and lower A-aDO2 and RI at T2 and T3 time points. Versus at the T0 time point, at each time point from T1 to T6, IL-8 and IL-10 levels were higher in both groups. Versus group C, group D had lower IL-8 and higher IL-10 levels at each time point from T1 to T6. CONCLUSION: In obese patients undergoing laparoscopic surgery under general anesthesia, the use of dexmedetomidine can improve the lung compliance and OI of the patients, inhibit the inflammatory response of the lungs of the patients and thus have a certain protective effect on the lung function.

Surgical Treatment for Endometrial Cancer, Hysterectomy Performed via Minimally Invasive Routes Compared with Open Surgery: A Systematic Review and Network Meta-Analysis.

Background: Total hysterectomy with bilateral salpingo-oophorectomy via minimally invasive surgery (MIS) has emerged as the standard of care for early-stage endometrial cancer (EC). Prior systematic reviews and meta-analyses have focused on outcomes reported solely from randomised controlled trials (RCTs), overlooking valuable data from non-randomised studies. This inaugural systematic review and network meta-analysis comprehensively compares clinical and oncological outcomes between MIS and open surgery for early-stage EC, incorporating evidence from randomised and non-randomised studies. Methods: This study was prospectively registered on PROSPERO (CRD42020186959). All original research of any experimental design reporting clinical and oncological outcomes of surgical treatment for endometrial cancer was included. Study selection was restricted to English-language peer-reviewed journal articles published 1 January 1995-31 December 2021. A Bayesian network meta-analysis was conducted. Results: A total of 99 studies were included in the network meta-analysis, comprising 181,716 women and 14 outcomes. Compared with open surgery, laparoscopic and robotic-assisted surgery demonstrated reduced blood loss and length of hospital stay but increased operating time. Compared with laparoscopic surgery, robotic-assisted surgery was associated with a significant reduction in ileus (OR = 0.40, 95% CrI: 0.17-0.87) and total intra-operative complications (OR = 0.38, 95% CrI: 0.17-0.75) as well as a higher disease-free survival (OR = 2.45, 95% CrI: 1.04-6.34). Conclusions: For treating early endometrial cancer, minimal-access surgery via robotic-assisted or laparoscopic techniques appears safer and more efficacious than open surgery. Robotic-assisted surgery is associated with fewer complications and favourable oncological outcomes.

Effects of Postoperative Gum Chewing on Recovery of Gastrointestinal Function Following Laparoscopic Gynecologic Surgery: Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Background: Chewing gum, considered a form of sham feeding, has been shown to improve intestinal motor and secretory function in various types of abdominal surgery. We conducted this systematic review to evaluate the effects of postoperative gum chewing on the recovery of gastrointestinal function after laparoscopic gynecologic surgery. Methods: We performed a comprehensive literature review of all randomized controlled trials (RCTs) in PubMed, Embase, and a reference list of relevant studies from the inception to 11 March 2024, comparing postoperative gum chewing versus no gum chewing following laparoscopic gynecologic surgery regardless of indications and setting without language restriction. The primary outcome was the time to the presence of bowel sounds and the time to the first passage of flatus. Cochrane's risk of bias tool was used to assess the risk of bias in included studies. Results: Nine RCTs with a total of 1011 patients were included. Overall, three studies were categorized as having a low risk of bias, three had some concerns, and three exhibited a high risk of bias. The time to the presence of bowel sounds (mean difference [MD] -2.66 h, 95% confidence interval [CI] -3.68 to -1.64, p < 0.00001) and time to the first passage of flatus (MD -4.20 h, 95% CI -5.79 to -2.61, p < 0.00001) was significantly shorter in the gum-chewing group. There was no statistical difference between the two groups with regard to the time to the first defecation (MD -6.52 h, 95% CI -15.70 to 2.66, p = 0.16), time to the first postoperative mobilization (MD 24.05 min, 95% CI -38.16 to 86.26, p = 0.45), postoperative ileus (MD 0.68, 95% CI 0.39 to 1.19, p = 0.17), and length of hospital stay (MD -0.05 day, 95% CI -0.14 to 0.04, p = 0.28). Conclusions: Gum chewing following laparoscopic gynecologic surgery appears to promote the recovery of gastrointestinal function, as evidenced by a reduced time to the presence of bowel sounds and the first passage of flatus.

Intraoperative Ultrasound: Bridging the Gap between Laparoscopy and Surgical Precision during 3D Laparoscopic Partial Nephrectomies.

The use of 3D laparoscopic partial nephrectomy has emerged as a cornerstone in the surgical arsenal for addressing renal tumors, particularly in managing challenging cases characterized by deeply seated tumors embedded within the renal parenchyma. In these intricate scenarios, the utilization of intraoperative ultrasound (IOUS) acquires paramount importance, serving as an indispensable tool for guiding and meticulously monitoring the surgical process in real time. To further explore the efficacy of IOUS-guided techniques, we conducted a retrospective study comparing outcomes in patients who underwent partial nephrectomy with IOUS guidance (n = 60) between 2020 and 2022 with a cohort from 2018 to 2019 without IOUS guidance (n = 25). Our comprehensive analysis encompassed various post-operative parameters, including the duration until food resumption, analgesia requirements, and length of the hospital stay. While these parameters exhibited comparable outcomes between the two groups, notable distinctions emerged in the intraoperative metrics. The IOUS-guided cohort demonstrated significantly reduced blood loss, a shorter median operative duration, and diminished ischemia time (p = 0.001). These compelling findings underscore the undeniable benefits of IOUS-guided techniques in not only facilitating the attainment of negative surgical margins but also in enhancing procedural safety and precision, thereby contributing to improved patient outcomes in the management of renal tumors.

Suture passer combined with two-hole laparoscopic peritoneal dialysis catheterization in patients undergoing peritoneal dialysis.

BACKGROUND: Laparoscopic techniques are being widely applied for peritoneal dialysis (PD) catheter (PDC) placement. The suture passer is a novel fixation tool that aims to reduce catheter migration. We compared the clinical value of the suture passer combined with two-hole laparoscopic PDC placement to open surgical placement by evaluating preoperative and postoperative conditions, as well as the onset of complications in both groups. METHODS: A retrospective study was conducted including 169 patients who underwent PDC placement surgery from January 2021 to May 2023. Based on the method employed, patients were divided into two groups: the suture passer combined with a two-hole laparoscopy group (SLG) and the open surgical group (SG). Comprehensive patient information, including general data, preoperative and postoperative indicators, peritoneal function after surgery, and the incidence rate of complications, were collected and analyzed. RESULTS: The SLG showed a statistically significant decrease in operative time, intraoperative blood loss, and 6-month postoperative drift rate compared to the SG (p < 0.05). No statistically significant differences were observed between the two groups in terms of sex, age, primary disease, hospitalization time, hospitalization costs, preoperative and postoperative examination indicators, peritonitis, and omental wrapping. CONCLUSIONS: Suture passer combined with two-hole laparoscopic PDC placement, characterized by simplicity and facilitating secure catheter fixation, was deemed safe and effective for patients undergoing PD. It reduces the catheter migration rate and improved surgical comfort. Overall, this technique demonstrates favorable outcomes in clinical practice.

Comparison of Prone With Lithotomy Position in Removal of Posterior Myoma in Transvaginal Natural Orifice Endoscopic Surgery: A Prospective Cohort Study.

OBJECTIVE: Vaginal natural orifice transluminal endoscopic surgery (vNOTES) is considered to have the advantages of completely scarless, less postoperative pain, earlier flatus, and faster postoperative recovery. However, posterior myoma are relatively difficult to operate through vNOTES in the conventional lithotomy position. Thus, we innovated the application of prone position in the removal of posterior myoma in vNOTES. The aim of this study is the comparison of myomectomy outcomes of patient for single posterior myoma in prone and lithotomy position. DESIGN: A single-center, prospective study. SETTING: A university teaching hospital. PATIENTS: A total of 81 patients with posterior myoma who underwent myomectomy in vNOTES from January 2021 to December 2022. INTERVENTIONS: The patients underwent myomectomy in vNOTES in prone or lithotomy position. MEASUREMENTS AND MAIN RESULTS: Among the patients who underwent vNOTES myomectomy, 29 (35.8%) were in the lithotomy position group, and 52 (64.2%) in the prone position group. Of note, 4 (4.9%) patients underwent a conversion to LESS during the operation-3 in the lithotomy and 1 in the prone position group. And a patient in the lithotomy position group underwent resurgery for hemostasis due to postoperative pelvic bleeding. Compared with the lithotomy position, prone position significantly shortens the operation time (12.3, 95% CI: 6.811, 17.761. p = .009) without increasing the complications and postoperative discomfort of patients. CONCLUSION: Compared to the lithotomy position, the prone position provides greater convenience for operation and exhibits a lower rate of surgical conversion during the removal of single posterior myomas via vNOTES. Further, for patients selecting vNOTES, surgeons need to conduct sufficient preoperative evaluation, timely hemostasis during surgery, and timely surgical conversion if necessary to ensure patient safety.

Laparoscopic Treatment of Bulky Nodes in Primary and Recurrent Ovarian Cancer: Surgical Technique and Outcomes from Two Specialized Italian Centers.

(1) Background: Minimally invasive surgery (MIS) represents a feasible approach in early-stage ovarian cancer, while this question is still unsolved for advanced and recurrent disease. (2) Methods: In this retrospective, multicenter study, we present a series of 21 patients who underwent MIS for primitive or recurrent epithelial ovarian cancer (EOC) with bulky nodal metastasis and discuss surgical technique and outcomes in relation to the current literature. (3) Results: Complete cytoreduction at primary debulking surgery was obtained in 86% of cases. No complication occurred in our patients intraoperatively and only 11.1% of our patients experienced grade 2 and 3 postoperative complications. Notably, all the patients with isolated lymph nodal recurrence (ILNR) were successfully treated with a minimally invasive approach with no intra- or postoperative complications. (4) Conclusions: The results of our study are consistent with those reported in the literature, demonstrating that MIS may represent a safe approach in advanced and recurrent EOC with nodal metastasis if performed on selected patients by expert surgeons with an adequate setting and appropriate technique.

Surgical and Oncological Outcome of Laparoscopic Resection of Colorectal Cancers: A Single-Center Experience.

BACKGROUND: Laparoscopy is one of the major advances in surgery in the last 30 years and has many benefits. Although laparoscopy was initially used for resection of benign colon lesions, it is now widely used for colorectal cancer resections after strong evidence has confirmed its safety and efficacy. We aim to report both the surgical and oncological outcomes of our first series of laparoscopic colorectal cancer resections. METHODS: In 2013, a laparoscopic colorectal resection service was established in northern Iraq at Zheen Hospital, Erbil. Data from all consecutive colorectal cancers were collected. Patients with locally advanced diseases and those who required emergency operations for bowel obstruction or perforation were excluded. We analyzed demographic, operative, postoperative, and histopathological data for all patients who were included in the study. RESULTS: A total of 124 patients with colorectal cancers presented to our unit between January 2013 and January 2023. Only 112 patients fulfilled the inclusion criteria and underwent laparoscopic resections. The median age of the patients was 54.5 years. The majority of patients were men (n=62; 55.4%). In 39 patients (35%), the cancer was located in the sigmoid; in 33 patients (29.5%) the cancer was in the rectum. Laparoscopic anterior resection was the most common procedure (n=50; 45%), followed by right hemicolectomy in 17 cases (15.1%). The conversion rate to open surgery was 8% (nine cases). The most common causes of conversion to open surgery were dilated bowel loops and tumour adherence to other structures. The mean operative time was 190 minutes and the mean hospital stay was three days. No complications were reported in 94 patients (84%). Among the complications, wound infection was seen in seven patients (7.8%). There were six anastomotic leaks (6.7%). The mean number of lymph nodes harvested was 13. In 70 patients (62.5%), the lymph node count was ≥12 with a median of 13. The mean distal resection margin was 6 cm and 2.5 cm for colon and rectal resections, respectively. CONCLUSION: This study reveals that laparoscopic resection for colorectal cancers is surgically practicable and safe with the benefits of a short hospital stay, adequate resection margins, and adequate lymph node yield.

Laparoscopic-Assisted Resection for an Extra-gastrointestinal Stromal Tumor Arising From the Mesentery of the Small Intestine: A Case Report.

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors that arise in the muscular or submucosal layers of the gastrointestinal tract. Extra-gastrointestinal stromal tumors (EGISTs) are rare primary entities that develop outside the digestive tract which are histologically and immunologically similar to GISTs. We present the case of a 52-year-old female diagnosed with a primary EGIST arising in the small bowel mesentery four months after undergoing hormone therapy for multiple uterine myomas. Transvaginal ultrasonography and MRI revealed a pelvic mass suspected to be a GIST. The patient was treated with laparoscopic-assisted partial resection of the small bowel. Histopathological examination of the surgical specimen confirmed the diagnosis of an EGIST. Imatinib treatment was initiated, and no clinical evidence of recurrence or metastasis was detected postoperatively. Because EGISTs are extremely rare, the differences between EGISTs and GISTs, the degree of malignancy, and prognosis have not been fully investigated. Further studies are needed to accumulate additional cases. The present case shows that laparoscopic-assisted excision can be successfully used to manage EGISTs.

Minimally Invasive Ivor Lewis Esophagectomy.

Minimally invasive Ivor Lewis esophagectomy is a technically demanding operation that requires an experienced surgeon, assistant, and anesthesiologist. The preoperative workup should focus on the extent of disease and extent of resection required, as well as the cardiopulmonary fitness of the patient. Surgical outcomes show decreased postoperative pain, decreased morbidity largely due to a reduction in respiratory complications, and decreased length of stay. Quality metrics and 5-year overall survival are equivalent to traditional open esophagectomy.

Comparison of a robotic surgery program for rectal cancer: short- and long-term results from a comparative, retrospective study between two laparoscopic and robotic reference centers.

BACKGROUND: It is assumed that robotic-assisted surgery (RAS) may facilitate complex pelvic dissection for rectal cancer compared to the laparoscopic-assisted resection (LAR). The aim of this study was to compare perioperative morbidity, short- and long-term oncologic, and functional outcomes between the RAS and LAR approaches. METHODS: Between 2015 and 2021, all rectal cancers operated on by (LAR) or (RAS) were retrospectively reviewed in two colorectal surgery centers. RESULTS: A total of 197 patients were included in the study, with 70% in the LAR group and 30% in the RAS group. The tumor location and stage were identical in both groups (not significant = NS). The overall postoperative mortality rate was not significantly different between the two groups. (0% LAR; 0.5% RAS; NS). The postoperative morbidity was similar between the two groups (60% LAR vs 57% RAS; NS). The number of early surgical re-interventions within the first 30 days was similar (10% for the LAR group and 3% for the RAS group; NS). The rate of complete TME was similar (88% for the LAR group and 94% for the RAS group; NS). However, the rate of circumferential R1 was significantly higher in the LAR group (13%) compared to the RAS group (2%) (p = 0.009). The 3-year recurrence rate did not differ between the two groups (77% for both groups; NS). After a mean follow-up of three years, the incidence of anterior resection syndrome was significantly lower in the LAR group compared to the RAS group (54 vs 76%; p = 0.030). CONCLUSIONS: The use of a RAS was found to be reliable for oncologic outcomes and morbidity. However, the expected benefits for functional outcomes were not observed. Therefore, the added value of RAS for rectal cancer needs to be reassessed in light of new laparoscopic technologies and patient management options.

Type and approach of hysterectomy and oncological survival of women with stage II cancer of endometrium: a large retrospective cohort study.

Objective: To explore the association between the Type and approach of hysterectomy and oncological survival of women with stage II cancer of the endometrium. Patients and methods: 684 women with stage II endometrial cancer were included. Eligible cases were grouped by type of hysterectomy (simple hysterectomy or radical hysterectomy)and approach of hysterectomy (laparoscopy or laparotomy). The baseline characteristics were compared among groups. The survival outcomes (disease-free survival and overall survival) were calculated and compared among groups, and the underlying confounding factors were adjusted by the Cox proportional hazard regression analysis. Results: The radical hysterectomy group and the simple hysterectomy group had 217 cases and 467 cases, respectively. Between the groups, the difference in 5-year disease-free survival (87.3% versus 87.9%, HR=0.97, P=0.87) and 5-year overall survival (83.8% versus 83.8%, HR=0.95, P=0.95) was not statistically significant. The laparotomy group and the laparoscopy group had 277 cases and 407 cases, respectively. Between the groups, the difference in 5-year disease-free survival (88.7% versus 87.1%, HR=1.22, P=0.34) and 5-year overall survival (85.5% versus 82.7%, HR=1.00, P=0.99) was not statistically significant. Conclusion: For long-term oncological survival, radical hysterectomy is not superior to total hysterectomy in stage II endometrial cancer. Also, for stage II cancer of the endometrium, laparoscopic hysterectomy is as oncologically safe as open hysterectomy.

Appendiceal Signet Ring Cell Carcinoma Presenting As Acute Appendicitis: A Case Report.

Appendiceal signet ring cell carcinoma is an exceedingly rare neoplasm which makes up only 4% of carcinomas of the appendix. It is a rare cause of abdominal pain which can mimic acute appendicitis. This case reports a 77-year-old female who presented to the emergency room with a complaint of right lower quadrant abdominal pain. After exploratory laparoscopy and histopathological studies, the patient was found to have peritoneal carcinomatosis and appendiceal signet ring cell carcinoma. This diagnosis unfortunately carries a relatively poor prognosis due to its aggressive nature. This study discusses the etiology, prevalence, clinical findings, and treatment of a rare cause of abdominal pain. This report sheds light on the importance of early detection and treatment of appendiceal signet ring cell carcinoma.

Dense surface reconstruction using a learning-based monocular vSLAM model for laparoscopic surgery.

Augmented reality (AR) has seen increased interest and attention for its application in surgical procedures. AR-guided surgical systems can overlay segmented anatomy from pre-operative imaging onto the user's environment to delineate hard-to-see structures and subsurface lesions intraoperatively. While previous works have utilized pre-operative imaging such as computed tomography or magnetic resonance images, registration methods still lack the ability to accurately register deformable anatomical structures without fiducial markers across modalities and dimensionalities. This is especially true of minimally invasive abdominal surgical techniques, which often employ a monocular laparoscope, due to inherent limitations. Surgical scene reconstruction is a critical component towards accurate registrations needed for AR-guided surgery and other downstream AR applications such as remote assistance or surgical simulation. In this work, we utilize a state-of-the-art (SOTA) deep-learning-based visual simultaneous localization and mapping (vSLAM) algorithm to generate a dense 3D reconstruction with camera pose estimations and depth maps from video obtained with a monocular laparoscope. The proposed method can robustly reconstruct surgical scenes using real-time data and provide camera pose estimations without stereo or additional sensors, which increases its usability and is less intrusive. We also demonstrate a framework to evaluate current vSLAM algorithms on non-Lambertian, low-texture surfaces and explore using its outputs on downstream tasks. We expect these evaluation methods can be utilized for the continual refinement of newer algorithms for AR-guided surgery.