Characterizing close-focus lenses for microendoscopy.

Microendoscopes are commonly used in small lumens in the body, for which a focus near to the distal tip and ability to operate in an aqueous environment are paramount for navigation and disease detection. Commercially available distal optic systems below 1mm in diameter are severely limited, and custom micro lenses are generally very expensive. Gradient index of refraction (GRIN) singlets are available in small diameters but have limited optical performance adjustability. Three-dimensional (3D) printed monolithic optical systems are an emerging option that may be suitable for enabling high performance, close-focus imaging. In this manuscript, we compared the optical performance of three custom distal optic systems; a custom-pitch GRIN singlet, 3D-printed monolithic doublet, and 3D-printed monolithic triplet, with a nominal working distance (WD) of 1.5mm, 0.5mm and 0.4mm in 0.9% saline. These short WDs are ideal for microendoscopy in collapsed or flushed lumens such as pancreatic duct or fallopian tube. The GRIN singlet had performance limited only by the fiber bundle relay over 0.9mm to 1.6 mm depth of field (DOF). The 3D printed doublet was able to achieve a comparable DOF of 0.71mm, while the 3D printed triplet suffered the most limited DOF of 0.55mm. 3D printing enables flexible design of monolithic multi-element systems with aspheric surfaces of very short WDs and relative ease of integration.

Pectopexy vs sacrocolpopexy: an analysis of 50 cases in a North American hospital.

BACKGROUND: Laparoscopic pectopexy is an alternative to sacrocolpopexy that was first reported in 2010. This procedure has been performed at our hospital since 2019 in patients with contraindications to sacrocolpopexy. OBJECTIVE: This study aimed to compare the outcomes of 50 cases of pectopexy with historical outcomes data for sacrocolpopexy. STUDY DESIGN: This was a retrospective review of 50 laparoscopic pectopexies performed from July 2020 to July 2022 at an academic tertiary referral center; this was the second reported use of this technique in North America. The outcomes from laparoscopic pectopexy were compared with laparoscopic sacrocolpopexy performed at the same institution by the same surgeons (n=207). The primary outcomes were complication rate, rate of recurrent prolapse (stage II or greater), and reoperation. RESULTS: Overall complication rates were 6.0% for pectopexy and 16.5% for sacrocolpopexy (relative risk, 0.79; P=.65). Recurrent prolapse was seen among 2.0% of patients who underwent pectopexy and 6.3% of patients who underwent sacrocolpopexy at most recent follow-up (relative risk, 1.27; P=.66). The rates of reoperation were 2.0% for pectopexy and 3.9% for sacrocolpopexy (relative risk, 1.04; P=.96). The average operative times were 138 minutes for pectopexy and 158 minutes for sacrocolpopexy. The average lengths of follow-up were 88.1 days for pectopexy and 325.5 for sacrocolpopexy. CONCLUSION: Although pectopexy was typically employed in patients with extensive pelvic adhesions or other conditions that placed them at higher risk of complications, both the success rate and the adverse event rate were similar to those in the historical cohort who underwent sacrocolpopexy. Although sacrocolpopexy remains the gold standard operation for apical prolapse, our data suggest that pectopexy can be employed to offer similar outcomes in many patients with contraindications to sacral fixation. These data give us increasing confidence that we can counsel our patients that this operation is likely to produce an outcome similar to a sacrocolpopexy.

Iterative prototyping based on lessons learned from the falloposcope in vivo pilot study experience.

Significance: High grade serous ovarian cancer is the most deadly gynecological cancer, and it is now believed that most cases originate in the fallopian tubes (FTs). Early detection of ovarian cancer could double the 5-year survival rate compared with late-stage diagnosis. Autofluorescence imaging can detect serous-origin precancerous and cancerous lesions in ex vivo FT and ovaries with good sensitivity and specificity. Multispectral fluorescence imaging (MFI) can differentiate healthy, benign, and malignant ovarian and FT tissues. Optical coherence tomography (OCT) reveals subsurface microstructural information and can distinguish normal and cancerous structure in ovaries and FTs. Aim: We developed an FT endoscope, the falloposcope, as a method for detecting ovarian cancer with MFI and OCT. The falloposcope clinical prototype was tested in a pilot study with 12 volunteers to date to evaluate the safety and feasibility of FT imaging prior to standard of care salpingectomy in normal-risk volunteers. In this manuscript, we describe the multiple modifications made to the falloposcope to enhance robustness, usability, and image quality based on lessons learned in the clinical setting. Approach: The ∼0.8 mm diameter falloposcope was introduced via a minimally invasive approach through a commercially available hysteroscope and introducing a catheter. A navigation video, MFI, and OCT of human FTs were obtained. Feedback from stakeholders on image quality and procedural difficulty was obtained. Results: The falloposcope successfully obtained images in vivo. Considerable feedback was obtained, motivating iterative improvements, including accommodating the operating room environment, modifying the hysteroscope accessories, decreasing endoscope fragility and fiber breaks, optimizing software, improving fiber bundle images, decreasing gradient-index lens stray light, optimizing the proximal imaging system, and improving the illumination. Conclusions: The initial clinical prototype falloposcope was able to image the FTs, and iterative prototyping has increased its robustness, functionality, and ease of use for future trials.

Laparoscopic pectopexy for patients with intraabdominal adhesions, lumbar spinal procedures, and other contraindications to sacrocolpopexy: a case series.

Laparoscopic pectopexy is an alternative to sacrocolpopexy utilizing fixation points in the anterior pelvis for vaginal vault suspension; it was originally developed for an obese population. This is a retrospective case series of 7 women who underwent laparoscopic pectopexy at one academic Institution between October 2019 and December 2020. The patients had preoperative vaginal vault prolapse (pelvic organ prolapse quantification system [POP-Q], stage 2 and 3). Pectopexy was performed because of relative contraindications to sacrocolpopexy, including use of antiplatelet therapy, extensive adhesions, and chronic back pain with lumbo-spinal fusion. No intraoperative complications were documented in this cohort. Average blood loss was 32.9 mL. All the patients were discharged home within 24 hours. One patient experienced urinary retention that required release of the retropubic midurethral sling placed at the time of pectopexy. The most recent follow-up examination occurred at an average of 127 days after the procedure. All 7 patients had a resolution of their prolapse (POP-Q ≤1). This case series highlights the application of pectopexy for patients with extensive adhesions, use of antiplatelet therapy and lumbar or sacral spinal surgical history. The complication rates and operative results are comparable with sacrocolpopexy at intermediate-term follow-up in this small case series, indicating that pectopexy may be a promising alternative for patients with relative contraindications to sacrocolpopexy. This is the first report of the application of the technique in North America.

Study of fallopian tube anatomy and mechanical properties to determine pressure limits for endoscopic exploration.

Falloposcopy is the endoscopic examination of the fallopian tubes, which are challenging to access due to their deep body location, small opening from the uterus, and lumen filled with plicae. We and others have developed endoscopes that are inserted through the uterus guided by a hysteroscope into the tubal ostium. To better understand how to utilize these endoscopes either as standalone devices or in concert with everting delivery balloons, a preliminary study of anatomy and mechanical behavior was performed ex vivo on porcine and human fallopian tubes. Segments of fallopian tubes from the isthmus, ampulla and infundibulum were inflated with saline either to bursting or held at sub-burst pressures with saline or a saline-filled balloon. Formalin fixed, paraffin embedded tissue sections stained with Masson's trichrome were examined for damage to the mucosa and muscularis. Porcine fallopian tubes tolerated saline pressurization at 15 psi for 1 minute without morphological damage. Balloon inflation to 15 psi caused no apparent damage to the muscle layer or rupture of the fallopian tube, but balloon movement within the tube can denude the mucosal epithelial layer. Human fallopian tubes averaged higher burst pressure values than porcine tubes. Under pressurization, the external tube diameter expanded by minimal to moderate amounts. Human and porcine tissues were similar in histological appearance. These studies suggest that moderate pressurization is acceptable but will not appreciably expand the fallopian tube diameter. The results also indicate that pigs are a reasonable model to study damage from falloscopy as seen in human tissue.

Sub-millimeter endoscope demonstrates feasibility of in vivo reflectance imaging, fluorescence imaging, and cell collection in the fallopian tubes.

SIGNIFICANCE: Most cases of high-grade serous ovarian carcinoma originate as serous tubal intraepithelial carcinoma (STIC) lesions in the fallopian tube epithelium (FTE), enabling early endoscopic detection. AIM: The cell-acquiring fallopian endoscope (CAFE) was built to meet requirements for locating potentially pathological tissue indicated by an alteration in autofluorescence or presence of a targeted fluorophore. A channel was included for directed scrape biopsy of cells from regions of interest. APPROACH: Imaging resolution and fluorescence sensitivity were measured using a standard resolution target and fluorescence standards, respectively. A prototype was tested in ex vivo tissue, and collected cells were counted and processed. RESULTS: Measured imaging resolution was 88 µm at a 5-mm distance, and full field of view was ∼45 deg in air. Reflectance and fluorescence images in ex vivo porcine reproductive tracts were captured, and fit through human tracts was verified. Hemocytometry counts showed that on the order of 105 cells per scrape biopsy could be collected from ex vivo porcine tissue. CONCLUSIONS: All requirements for viewing STIC in the FTE were met, and collected cell counts exceeded input requirements for relevant analyses. Our benchtop findings suggest the potential utility of the CAFE device for in vivo imaging and cell collection in future clinical trials.

Triple-modality co-registered endoscope featuring wide-field reflectance imaging, and high-resolution multiphoton and optical coherence microscopy.

We present the design and feasibility testing of a multimodal co-registered endoscope based on a dual-path optical system integrated with a scanning piezo. This endoscope incorporates three different imaging modalities. A large field of view reflectance imaging system enables visualization of objects several millimeters in front of the endoscope, while optical coherence microscopy and multiphoton microscopy are employed in contact with tissue to further analyze suspicious areas. The optical system allows multiple different imaging modalities by employing a dual optical path. One path features a low numerical aperture and wide field of view to allow reflectance imaging of distant objects. The other path features a high numerical aperture and short working distance to allow microscopy techniques such as optical coherence microscopy and multiphoton microscopy. Images of test targets were obtained with each imaging modality to verify and characterize the imaging capabilities of the endoscope. The reflectance modality was demonstrated with a 561 nm laser to allow high contrast with blood vessels. It achieved a lateral resolution of 24.8 µm at 5 mm and a working distance from 5 mm to 30 mm. Optical coherence microscopy (OCM) was performed with a 1300 nm super-luminescent diode since this wavelength experiences low relative scattering to allow for deeper tissue imaging. Measured OCM lateral and axial resolution was 4.0 µm and 14.2 µm, respectively. Multiphoton microscopy (MPM) was performed with a custom 1400 nm femtosecond fiber laser, a wavelength suitable for exciting multiple exogenous and some endogenous fluorophores, as well as providing information on tissue composition through harmonic generation processes. A 4.0 µm MPM lateral resolution was measured.

Simple and effective: transvaginal vesico-vaginal fistula repair with a modified Latzko technique.

INTRODUCTION AND HYPOTHESIS: The incidence of vesico-vaginal fistulas after hysterectomies for benign indications in developed countries is less than one percent. The objective of this video is to demonstrate an easy-to-follow, step-by-step approach to repairing a small, uncomplicated vesico-vaginal fistula transvaginally using a modified Latzko technique. METHODS: In this video, we present a case of a 46-year-old woman who developed a simple, uncomplicated vesico-vaginal fistula after a total abdominal hysterectomy. To correct her fistula, we used a modified Latzko technique, which is a transvaginal approach to vesico-vaginal fistula repair that involves mobilizing the vaginal mucosa around the fistula and then closing the pubo-vesical fascia and vaginal mucosa in layers. RESULTS: The patient had successful surgical correction of her vesico-vaginal fistula without recurrence of the fistula. CONCLUSIONS: For small, uncomplicated vesico-vaginal fistulas, a transvaginal approach has an equivalent success rate to that of other approaches with less invasiveness and faster recovery times. Therefore, it is reasonable to use a modified Latzko technique to help restore the quality of life to women affected by small, uncomplicated vesico-vaginal fistulas.