Avascular Space Research Articles

Laparoscopic Management of Posthysterectomy Vesicovaginal Fistula

Video Objective To show our standardized method to surgically tackle posthysterectomy vesicovaginal fistulas by laparoscopy. Setting Universitary hospital, and reference center for gynecological diseases. Interventions We present two cases of posthysterectomy vesicovaginal fistulas referred to our hospital. Both had abdominal prior hysterectomies. We maintained Foley´s catheter 3 months prior to definitive surgery to avoid usual acute inflamation surrounding the fistula. We followed a very standardized method which consists of 5 steps: 1.- Anatomical survey / Adhesiolysis, 2.- Identification of vesicovaginal avascular space, 3.- Fistula identification, 4.- Further dissection of the vesico vaginal space, 5.- Individual vesical and vaginal defect closure. Conclusion Both patients were discharged 48 hours after surgery. Foley´s catheter was maintained for 14 days. We had performed such surgery in 6 consecutive cases with no fistula relapse.

Laparoscopic Variants of Temporary Uterine Artery Ligation

ObjectiveLaparoscopic uterine artery ligation may be performed during myomectomy or other uterine invasive procedures to reduce the amount of blood loss during surgery. In this video, the authors describe 3 different laparoscopic techniques to approach the uterine artery. DesignStep-by-step video demonstration of 3 different surgical techniques. SettingPrivate hospital in Curitiba, Paraná, Brazil. InterventionsThe main steps of uterine artery ligation are described in detail as well as different laparoscopic variants to this procedure. Anterior ApproachThe impression of the uterine vessels can usually be seen anteriorly and laterally to the uterine cervix. After identification of the path of the uterine arteries, the peritoneum of the anterior cul-de-sac is opened over the vessels and the uterine artery is carefully dissected next to the lateral border of the uterine cervix. This dissection must be performed with extreme caution because the uterine veins are very close to the artery. Venous bleeding at this point of the dissection can be very difficult to control without ligating the vessels. After circumferential dissection of the artery, temporary occlusion is conducted using 2-0 polyester suture. Posterior Approach, Lateral to the Infundibulopelvic LigamentFor ligation of the uterine artery posteriorly to the uterus and laterally to the pelvic infundibulum, opening of the peritoneum of the broad ligament should start immediately below the round ligament, parallel and medial to the external iliac vessels toward the base of the pelvic infundibulum. The avascular space is dissected by blunt dissection (traction and countertraction), identifying the lateral (external iliac vessels) and medial (pelvic infundibulum and the ureter attached to the peritoneum of the ovarian fossa) landmarks. The external iliac artery is dissected cranially to find the bifurcation of the common iliac artery and the internal iliac artery. The first medial branch of the anterior division of the internal iliac usually is the uterine artery. After circumferential dissection of the uterine artery, it may be ligated according to the same technique described above. Medial ApproachFor the medial approach, the peritoneum should be opened medial to the infundibulopelvic ligament. The assistant grasps the infundibulopelvic ligament, creating a peritoneal tent. Immediately after broad ligament opening, anatomic landmarks are identified. First, the ureter is identified and medialized. For the identification of vascular anatomy, movement of the obliterated umbilical artery is made active, which reduces the risk of error to ligate the uterine artery. After circumferential dissection of the artery, it may be ligated according to the same technique described above. ConclusionLaparoscopic uterine artery ligation may be performed during laparoscopic myomectomy to reduce intraoperative blood loss. According to the position of the myomas within the uterus as well as the uterine volume, the surgeon may choose among 1 of the above-mentioned techniques to perform. This technique could also be applied to other types of invasive uterine procedures to reduce blood loss. Standardization of these techniques could help to reduce the laparoscopic learning curve.

Basic clinical retroperitoneal anatomy for pelvic surgeons.

Basic anatomical knowledge should be improved during residency period with clinical practice. Especially pelvic surgeons; obstetricians, gynecologists, gynecological oncologists, urologists and general surgeons must have an advanced level practise of retroperitoneal anatomy to gain surgical skills. Retroperitoneal topographic anatomy, retroperitoneal vasculature, ureteric dissection and pelvic avascular spaces are the precise points during pelvic surgery.

How to do: technique of liver hanging maneuver—step by step

In 2001, Belghiti et al. described a technique called “liver hanging maneuver” (LHM): consisting in lifting the liver during parenchymal transection by a tape passed between the anterior surface of inferior vena cava (IVC) and the liver. In this manner surgeons achieve the effective vascular control especially for the deeper parenchymal transection and a guidance of the direction of anatomic parenchymal transection. LHM can be performed due to the existence of a longitudinal avascular and virtual space between anteriorly the posterior face of liver and posteriorly the anterior face of IVC. We use this method, which is adopted routinely by the Reims Team, and is it similar to the one described by Belghiti with some peculiarities: it is a combined bidirectional up and down (or cranio-caudal) approach. We show step by step how to perform a safety LHM. We adopted a dissection of the avascular space using: (I) smooth and gently movements; (II) hydro-dissection; (III) 14 Fr nasogastric tube. We think our video can help surgeons especially junior surgeons to understand better LHM and maybe to reproduce it more facility, reducing any risks correlated to this maneuver.

The liver hanging maneuver revisited: a cadaveric study of the width of the retro-hepatic avascular space

The liver hanging maneuver revisited: a cadaveric study of the width of the retro-hepatic avascular space

The liver hanging maneuver revisited: a cadaveric study of the width of the retro-hepatic avascular space

Background: Since being described by Belghiti in 2001, the liver hanging maneuver for anterior resection is widely used. A literature review shows a success rate greater than 90%. Various devices such as a 10Fr nasogastric tube and a Penrose drain have been utilized for lifting the liver. We sought to determine the appropriate size of the hanging tapes by measuring the size of the retro-hepatic avascular space in cadaveric livers. Methods: Forty three adult cadavers were used in this study, preserved in 10% formaldehyde. After entering the abdominal cavity, the entire liver, along with the retro-hepatic vena cava, the hepatic artery, the portal vein and the bile duct, was removed, as is performed in harvesting the liver for transplantation. The vena cava was opened posteriorly “ex vivo” and the proper and short hepatic veins examined from the inside. The size of the retro-hepatic avascular area was measured. Results: The distance between the hepatic veins in the retro-hepatic avascular space ranged from 3 to 19 mm in width, with a median of 7 mm. The liver hanging maneuver was deemed feasible in almost 80% of the specimen that had 5 mm or greater distance. In ten specimens measuring 4 mm or less, however, suture ligation of the caudal short hepatic veins seemed necessary before passing a tape. Conclusion: The retro-hepatic avascular space is 5mm or larger in a majority of specimens examined and the size of the hanging tape should be selected accordingly.

Racial differences in the correlations between structural parameters and ocular blood flow in healthy eyes

Purpose: This study aimed to assess differences in the relationship between structural parameters and ocular blood flow between persons of African (AD) and European descent (ED) with healthy eyes.Methods: The relationship between structural and ocular blood flow parameters was assessed in 46 participants (20 AD, 26 ED) with healthy eyes. Disc area (DA), rim area (RA), and retinal nerve fiber layer (RNFL) thickness were measured. Retrobulbar blood flow was assessed in the ophthalmic (OA), central retinal (CRA), nasal (NPCA) and temporal short posterior ciliary arteries (TPCA). Peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive index (RI) were assessed. Retinal capillary blood flow was also evaluated. Differences between the correlations were determined using the Fisher r-to-z transformation.Results: Significant differences in correlations were observed between the AD and ED groups in the CRA, where PSV and DA were positively correlated in AD (r=0.43) and negatively correlated in ED (r=-0.36) (Δr=0.79; P=0.01). A similar finding was observed for PSV and RA (AD: r=0.39; ED: r=-0.23; Δr=0.62; P=0.04). In the inferior hemifield for ED group only, percentage of avascular space and RNFL thickness were positively correlated (r=0.51, P=0.01) and mean retinal flow and RNFL thickness were negatively correlated (r=-0.50, P=0.01).Conclusion: The relationship between structural parameters and the blood supply to the superficial layer of the retina was significantly different in the healthy eyes of AD compared to ED. More research is required to show how these differences may affect glaucomatous risk.

Identification of external branch of superior laryngeal nerve during thyroid surgery: a prospective study

<p class="abstract"><strong>Background:</strong> Identification of external branch of superior laryngeal nerve (EBSLN) according to Cernea et al classification and to describe a surgical technique of superior pole dissection to preserve EBSLN during thyroid surgeries.</p><p class="abstract"><strong>Methods:</strong> The study was done over 2 years period in a tertiary care hospital. 105 nerves were studied among the 90 patients who underwent thyroid surgeries. Avascular dissection over the JOLL’S triangle was carried out and identified EBSLN were classified according to Cernea et al classification. Individual ligation of superior pole vessels was carried out after identifying the nerve. Outcome was studied relating the identified nerve with sides of thyroidectomy performed, size of thyroid gland and nerves at risk according to Cernea et al classification. </p><p class="abstract"><strong>Results:</strong> Of the 105 nerves studied, in 81.90% of patients the nerve was identified. There were 34.88% of Type 1 nerves, 52.33% of Type 2A nerve and 12.79% of Type 2B nerves identified. Less number of nerves could be identified on the left side. Type 2B nerves were more common on left side inspite of less number of dissections carried out on left. Type 2 variation was more common in large goiters.</p><p><strong>Conclusions:</strong> Careful dissection should be done in superior pole in avascular cricothyroid space, with lateralization of superior pole and individual identification of superior pole vessels once the nerve is identified. Identification of the nerve is mandatory in all patients who undergo thyroid surgery for optimal functions of the larynx. These results showed a better identification of nerves by proper surgical techniques without use of any sophisticated equipments. </p>

Transabdominal cerclage (TAC) for patients with ultra-short uterine cervix after uterine cervix surgery and its impact on pregnancy.

Patients with an ultra-short uterine cervix as a result of large conization, repeated conization or radical trachelectomy (RT), are at high risk of preterm premature rupture of the membrane, which leads to preterm birth. We have commenced performing transabdominal cerclage (TAC) of the uterine cervix for these patients. In this study, we examined the safety of TAC and its impact on pregnancy. We have performed TAC in 11 patients before pregnancy: in six after large cervical operations, such as repeated conization; and in five for difficulties with cervical cerclage after RT. After laparotomy, a Teflon thread was placed in the avascular space between the uterine vessels and the uterine muscle, and tied. The clinical course of the patients after TAC and their pregnancy course were retrospectively reviewed. TAC was performed safely without any complications. The mean operative duration was 53 ± 10 min, and the mean blood loss during the operation was 49 ± 64 mL. Seven women conceived within 2 years after TAC. Their pregnancy courses were favorable. Five of the women underwent scheduled cesarean sections, while two pregnancies are ongoing. Although there are risks of various complications as a result of the use of non-absorbable thread and the need for two extra laparotomies, TAC can be a safe and useful option for patients who show cervical incompetence after large uterine cervical operations, such as RT or large conization.

Importance of the Moskowitz artery in the laparoscopic medial approach to splenic flexure mobilization: a cadaveric study.

The medial approach in laparoscopic splenic flexure mobilization is based on the entrance to the lesser sac just above the ventral edge of the pancreas (VEOP). The artery of Moskowitz runs through the base of the mesocolon, just above the VEOP. The aim of this study was to assess the incidence of the artery of Moskowitz, its route and its distance from the VEOP. We performed a cadaveric study on 27 human cadavers. The vascular arcades of the splenic flexure were dissected, the number of vascular arches, and the origin and localization of its terminal anastomosis were recorded. The splenic flexure avascular space (SFAS) was defined as the avascular zone in the mesocolon delimited by the VEOP, middle colic artery, ascending branch of the left colic artery and the vascular arch of the splenic flexure nearest to the VEOP and was quantified as the distance between the VEOP and the most proximal arch RESULTS: The artery of Drummond was identified in 100% of the cadavers. In 5 of 27 (18%) Riolan's arch was present, and in 3 of 27 (11%) the Moskowitz artery was found. The mean distance from the VEOP to the artery of Moskowitz was 0.3cm (SD 0.04). This vascular arch travelled from the origin of the middle colic artery to the distal third of the ascending branch of the left colic artery. The SFAS was greater (p=0.001) in cadavers that only presented the artery of Drummond (mean 6.8cm; SD 1.25) than in those with Riolan's arch (mean 4.5cm; SD 0.5) CONCLUSIONS: In the medial approach for laparoscopic mobilization of the splenic flexure, when only one of the arches is present, the avascular area is an extensive and secure territory. If the artery of Moskowitz is present, the area is nonexistent and this would contraindicate the approach due to risk of iatrogenic bleeding. A radiological preoperatory study could be essential for accurate and safe surgery in this area.

Robotic-Assisted Excision of a Urachal Diverticulum

Study ObjectiveTo demonstrate a combined robotic-assisted laparoscopic technique with concomitant cystoscopy use for excision of a urachal diverticulum to ensure complete resection of diverticulum and bladder cuff. DesignStep-by-step demonstration and explanation of the procedure using video illustration. Institutional Review Board/Ethics Committee ruled that approval was not required for this case report; however, patient consent was obtained (Canadian Task Force Classification III). SettingVesicourachal diverticula account for approximately 3% to 5% of congenital urachal anomalies. Although usually asymptomatic, the diverticulum may be associated with an increased risk of urinary tract infections, intraurachal stone formation, and an increased prevalence of carcinoma after puberty. When diverticula become symptomatic or infected, surgical management is warranted. PatientA 68-year-old gravida 0 woman was evaluated with cystoscopy for recurrent culture-proven urinary tract infections. A suspected vesicourachal diverticulum was identified on cystoscopy, and the diagnosis was confirmed on computed tomography. She was counseled on management options and elected to undergo robotic-assisted excision of the urachal remnant with concomitant cystoscopy. InterventionAfter identifying the diverticulum both laparoscopically and on cystoscopy, the anterior peritoneum was incised to dissect the diverticulum off the anterior abdominal wall. The dissection was carried down to the level of the bladder dome, necessitating entry into the retropubic space of Retzius. A partial cystectomy was performed to ensure complete resection of the diverticulum. The bladder was repaired in 2 layers. Concurrent laparoscopy and cystoscopy allowed for assurance of watertight closure by retrograde filling of the bladder and observing laparoscopically. Although entered, the space of Retzius is an avascular potential space between the pubic symphysis and the bladder and does not necessitate closure. Surgery was performed successfully without intraoperative or postoperative complications. On final pathology, a benign urachal diverticulum was completely excised. The patient’s presenting symptoms resolved postoperatively. ConclusionRobotic-assisted excision of a vesicourachal diverticulum with concomitant use of cystoscopy is a safe, effective, and efficient technique for successful, minimally invasive, management of symptomatic urachal diverticula.

Laparoscopic Nerve-Preserving Sacropexy

Study ObjectiveTo demonstrate our developed nerve-preserving technique during laparoscopic sacropexy (LSP) for multicompartment pelvic organ prolapse. DesignA step-by-step demonstration of our surgical procedure on video (Canadian Task Force classification II-2). Informed consent was obtained from the subject, and the applicable Institutional Review Board provided approval. SettingAlthough sacropexy does remain the ‘gold standard’ procedure for apical prolapse [1], the subjective outcome of the procedure has been reported to be not so satisfactory as its anatomic outcome [2]. New onset bowel symptoms have been observed with voiding and sexual dysfunctions [3]. Published data revealed a correlation between iatrogenic denervation during LSP and postoperative dysfunctions [4-6]. We adopted a nerve-preserving approach with the aim of reducing the iatrogenic morbidity. InterventionsOur surgical nerve-preserving LSP technique from the promontory down to the right uterosacral ligament and the rectovaginal space proceeds in 3 steps:Step 1: Opening the peritoneum. The peritoneum is opened just medial to the right common iliac artery, approximately 20 to 30 mm above the sacral promontory, allowing a safe approach in an area far from nerves and vascular structures. Peritoneal incision is extended toward the promontory. The underlying presacral fascia containing the right hypogastric nerve (rHN) is identified and incised longitudinally. The presacral fascia and the rHN are then pushed medially to expose the longitudinal anterior vertebral ligament; the finding of the middle sacral veins represents the limit of any further medial dissection. Opening and displacement of the prevertebral fascia are not mandatory.Step 2: Opening the peritoneum of the right pelvic sidewall, respecting the integrity of the presacral fascia and of the rHN contained within it. An inverted L-shaped peritoneal incision extending from the sacral promontory up to the left uterosacral ligament is completed, with care taken to preserve the rHN identified previously. In proximity to the uterus, the dissection line crosses the upper edge of the right uterosacral ligament at its proximal third and extends medially. The rectovaginal space is opened and joined to the peritoneal tunnel with a section of the superficial layer of the right uterosacral ligament, preserving its deep nervous portion.Step 3: Dissection of the rectovaginal space, respecting the integrity of the rectal fascia. The rectovaginal space is fully dissected, and at its caudal edge the dissection is carried out laterally to the rectum upward to identify the pelvic parietal fascia covering the levator ani muscle, in the middle to the cranial edge of the perineal body. Preservation of the rectal fascia prevents possible injury to the middle rectal vessels and the rectal branches of the inferior hypogastric plexus, which runs close to the pelvic floor.The complete dissection of the rectovaginal space appears in an inverted V-shaped space covering approximately two-thirds of the posterior vaginal wall, with the apex at the convergence of the uterosacral ligaments. The procedure is completed with dissection of the vesicovaginal space through the creation of an avascular triangular-shaped space with the apex at the dorsal end of the bladder trigone and laterally limited by the superficial vascular layer of the vesicouterine ligaments. The bladder branches of the inferior hypogastric plexus run far from the surgical field in the deep portion of the vesicouterine ligaments. ConclusionA nerve-sparing approach to pelvic spaces during LSP is feasible following well-defined surgical steps, which allow the surgeon to visualize all of the nerve pathways and potentially dangerous anatomic structures.

Baseline characteristics predictive of structural and functional progression in open-angle glaucoma patients with different demographic characteristics

Purpose: The aim of this study was to examine ocular blood flow parameters that may predict structural and functional disease progression in open-angle glaucoma (OAG) patients of different diabetic status, gender, ethnicity, and body mass index (BMI).Methods: One hundred twelve patients with OAG were assessed for systemic blood pressure (BP), ocular perfusion pressure (OPP), retrobulbar blood flow, capillary blood flow, and optic nerve head morphology at baseline and every six months for a five-year period. Structural progression was monitored with optical coherence tomography and Heidelberg retinal tomography-III. Functional disease progression was monitored with automated perimetry using Humphrey visual fields. Factors associated with OAG structural and functional progression were analyzed using Cox proportional hazards models.Results: The following were associated with shorter time to structural progression: In diabetic patients, larger area of avascular space; in males, lower central retinal artery peak systolic velocity and end diastolic velocity; in patients of African descent, higher systolic BP and OPP; in obese patients, lower ophthalmic artery end diastolic velocity. The following were associated with shorter time to functional progression: In diabetic patients, cup area, cup volume, cup/disc area ratio, linear cup/disc ratio, mean cup depth, cup shape; in males, systolic BP, diastolic BP, mean arterial pressure, systolic PP, diastolic PP, OPP, mean PP; in overweight patients, higher ophthalmic artery and central retinal artery resistive indices; in obese patients, lower central retinal artery resistive index.Conclusions: Structural and functional OAG disease progression may be influenced differently in patients based on diabetic status, gender, ethnicity, and BMI. Mathematical modeling of risk variables that takes into account demographic characteristics may assist in better identifying OAG progression risk.

Differences in Ocular Blood Flow Between People of African and European Descent With Healthy Eyes.

To investigate differences in ocular blood flow between people of African descent (AD) and European descent (ED) with healthy eyes. Retrobulbar and retinal capillary blood flow was assessed in 1 eye of 58 participants (24 AD, 34 ED) with healthy eyes with systemic blood pressure lower than 140/90. Retrobulbar blood flow was measured in the ophthalmic artery (OA), central retinal artery (CRA), nasal posterior ciliary artery (NPCA) and temporal posterior ciliary artery (TPCA). Peak systolic velocity (PSV), end diastolic velocity (EDV), and resistive index (RI) were assessed. Retinal capillary blood flow was assessed using mean retinal flow and avascular space defined as the percent of area measured with no blood flow. Groups were compared using t tests and Pearson correlations were compared using Fisher r-to-z transformation. Compared with people of ED, people of AD had significantly lower EDV in the NPCA (P=0.01), and higher RI in the CRA (P=0.04) and TPCA (P=0.01). No significant differences were observed in mean retinal capillary flow or avascular area. In the CRA, a significant negative correlation was observed between pattern standard deviation and peak systolic velocity (P=0.02) in the AD group and this correlation was significantly different from that observed in the ED group (P=0.01). A significant correlation was also observed between pattern standard deviation and EDV (0.04) in the AD group. This study suggests that retrobulbar blood flow is lower in healthy eyes in persons of AD compared with ED. This may provide a mechanism through which people of AD are at increased risk for ophthalmic diseases such as glaucoma.

Single-port laparoscopic transperitoneal infrarenal para-aortic lymphadenectomy as part of staging operation for early ovarian cancer and high grade endometrial cancer.

ObjectiveThe aim of this paper was to demonstrate the techiniqes of single-port laparoscopic transperitoneal infrarenal paraaortic lymphadenectomy as part of surgical staging procedure in case of early ovarian cancer and high grade endometrial cancer.MethodsAfter left upper traction of rectosigmoid, a peritoneal incision was made caudad to inferior mesenteric artery. Rectosigmoid was mobilized, and then the avascular space of the lateral rectal portion was found by using upward traction of rectosigmoid mesentery. Inframesenteric nodes were removed without injury to the ureter and the left common iliac nodes were easily removed due to the upward traction of the rectosigmoid. The superior hypogastric plexus was found overlying the aorta and sacral promontory, and presacral nodes were removed at subaortic area. Peritoneal traction suture to right abdomen was needed for right para-aortic lymphadenectomy. After right lower para-aortic node dissection, operator was situated between the patient’s legs. After upper traction of the small bowel, left upper para-aortic nodes were removed. To prevent chylous ascites, we used hemolock or Ligasure application (ValleyLab Inc.) to upper part of infrarenal and aortocaval nodes.ResultsSingle-port laparoscopic transperitoneal infrarenal para-aortic lymphadenectomy was performed without serious perioperative complications.ConclusionEven though the technique of single-port surgery is still a difficult operation, the quality of single-port laparoscopic transperitoneal infrarenal para-aortic node dissection is excellent, especially mean number of para-aortic nodes. In cases of staging procedures for ovary and endometrial cancer, single-port transperitoneal para-aortic lymphadenectomy is acceptable as an oncologic procedure.

Minimizing projection artifacts for accurate presentation of choroidal neovascularization in OCT micro-angiography.

Current optical coherence tomography (OCT) based micro-angiography is prone to a projection (or tailing) effect due to the high scattering property of blood within overlying patent vessels, creating artifacts that interfere with the interpretation of retinal angiographic results. In this work, the projection effect in OCT micro-angiography is examined and its causality is explained by strong light scattering and photon propagation within blood. A simple practical approach is then introduced to minimize these artifacts presented in the outer retinal avascular space, especially useful for examining clinical cases with choroidal neovascularization (CNV). Demonstrated through in-vivo human posterior eye imaging of healthy and CNV subjects, the proposed method is shown effective to eliminate the projection artifacts in outer retinal space of OCT micro-angiography, resulting in better visualization of the pathological neovascularization when compared with the current common approaches. In addition, it is also shown that the proposed method is applicable to minimize the projection artifacts appearing in deep retinal layers.

Development and clinical usefulness of the liver hanging maneuver in various anatomical hepatectomy procedures.

To assess the clinical application and usefulness of the liver hanging maneuver (LHM), proposed by Belghiti, for major hepatectomy, including its (1) historical development, (2) usefulness and application and (3) advantages and disadvantages, by reviewing the English literature published during the period 2001-2014. In major hepatic transection via the anterior approach, the deep area of transection around the vena cava is critical with regard to bleeding during right hemi-hepatectomy. Belghiti and other investigators identified avascular spaces that are devoid of short hepatic veins at the front of the vena cava and behind the liver. Forceps can be inserted into this space easily and then maneuvered to lift the liver using hanging tape. This procedure, termed LHM significantly reduces intraoperative blood loss and the transection time during right hemi-hepatectomy. LHM has been used in various anatomical hepatectomy procedures worldwide, including laparoscopic hepatectomy. The use of LHM markedly improves the amount of intraoperative blood loss, operative time and postoperative outcome. We conclude that the application of LHM is an important development in the field of liver surgery, although a further evaluation of its true impact on clinical outcomes is necessary.

Laparoscopic Discoid Anterior Rectal Excision with the Circular Stapler for Rectosigmoid Endometriosis, Performed by the Gynecologic Surgeon

Study ObjectiveTo demonstrate the technique of laparoscopic discoid anterior rectal wall resection using a circular stapler, feasible in the case of rectosigmoid endometriosis lesions measuring ≤3 cm. DesignCase report (Canadian Task Force classification III). SettingPrivate practice hospital in São Paulo, Brazil. PatientThirty-four-year-old woman with pelvic deep endometriosis including a 2-cm lesion in the rectosigmoid situated 11 cm proximally to the anal border. She had chronic pelvic pain, dysmenorrhea, dyspareunia, and constipation. She had undergone no previous surgical procedures. InterventionsStandard 4-puncture laparoscopy was performed, and all visible endometriosis lesions were first removed before proceeding to rectal resection. The avascular rectovaginal space was identified, and the rectosigmoid was mobilized cranially, releasing the vagina and increasing the final distance of the bowel anastomosis to the anal border. The rectosigmoid nodule was isolated in its entire circumference and remained restricted to the anterior wall of the bowel. It was then transfixed using a 2-0 polyglycolic suture, with the healthy proximal and distal limits of the bowel included in the suture. A 33-cm endoscopic circular stapler was introduced via the anus up to the distal limit of the lesion and opened inside the bowel lumen. By pulling the edges of the suture, the rectosigmoid nodule was introduced inside of the circular stapler. It was fired to resect the anterior rectal wall, and the anastomosis was situated at the anterior and lateral walls of the bowel. Integrity of the bowel was checked via infusion of saline solution with methylene blue dye. Gynecologic surgeons performed all of the procedures. Measurements and Main ResultsBowel resection took 20 minutes, and the entire surgical procedure lasted 120 minutes. The patient was discharged after 48 hours. There were no intercurrent events, either early or late postoperatively. The patient was symptom-free at 2 years of follow-up. ConclusionLaparoscopic discoid excision of an anterior rectal nodule using the circular stapler is an effective option for treating selected cases of rectosigmoid endometriosis. The technique might be reproducible by gynecologic surgeons after proper training.

Laparoscopic Dissection and Anatomy of Sacral Nerve Roots and Pelvic Splanchnic Nerves

Study ObjectiveTo demonstrate the technique of laparoscopic dissection for identification of sacral nerve roots and pelvic splanchnic nerves. DesignCase report (Canadian Task Force classification III). SettingPrivate practice hospital in São Paulo, Brazil. PatientA 31-year-old woman with suspected iatrogenic and/or compression of sacral nerve roots. She reported debilitating pelvic, gluteal, and perineal unilateral left-sided pain (score 8 on a pain scale of 0–10), and had primary infertility with 1 previous failed attempt at in vitro fertilization. Surgical history included laparoscopic excision of endometriosis 10 months before the procedure and left oophoroplasty during adolescence because of a benign neoplasm. InterventionsStandard 4-puncture laparoscopy was performed. The peritoneum of the left pelvic sidewall was resected to preclude eventual residual endometriosis. This also enabled identification of uterine vessels including the deep uterine vein, which is the limit between the pars vascularis superiorly and the pars nervosa inferiorly in the uterine broad ligament. Surgery was using the laparoscopic neuro-navigation (LANN) technique, previously described by one of us (M. P.). For identification of the sacral roots, dissection was begun medial to the ureter and lateral to the uterosacral ligament. The Okabayashi pararectal space was entered as deep as possible via blunt dissection in avascular spaces. Hemostasis was performed using 5-mm bipolar forceps, and harmonic energy was not used. The hypogastric fascia was entered from medial to lateral, and the piriformis muscle was identified. The sacral nerve root S1 was identified lying over it. Dissection then proceeded caudally, and sacral roots S2 and S3 were sequentially identified. Small and delicate fibers forming the pelvic splanchnic nerves were isolated emerging from sacral roots S2 and S3. Other nerve fibers were identified caudally, probably representing pelvic splanchnic nerves emerging from S4. Measurements and Main ResultsThe surgical operative time was 70 minutes, and bleeding was minimal. No suspected compression or iatrogenic injury was identified. The patient was discharged on the day after the procedure. At 8-month follow-up, she had partial resolution of pain (score 5, pain scale 0–10), and another failed attempt at in vitro fertilization was attributed to unsatisfactory quality of the embryos. There were no symptoms or dysfunctions attributable to manipulation of the nerves. ConclusionLaparoscopy is a useful tool for identification of sacral roots and pelvic splanchnic nerves in suspected diseases. Its application in the field of neuropelveology can be expanded with proper knowledge and training.

Development of gene therapy for treatment of age-related macular degeneration.

Intraocular neovascular diseases are the leading cause of blindness in the Western world in individuals over the age of 50. Age-related macular degeneration (AMD) is one of these diseases. Exudative AMD, the late-stage form, is characterized by abnormal neovessel development, sprouting from the choroid into the avascular subretinal space, where it can suddenly cause irreversible damage to the vulnerable photoreceptor (PR) cells essential for our high-resolution, central vision. The molecular basis of AMD is not well understood, but several growth factors have been implicated including vascular endothelial growth factor (VEGF), and the advent of anti-VEGF therapy has markedly changed the outcome of treatment. However, common to all current therapies for exudative AMD are the complications of repeated monthly intravitreal injections, which must be continued throughout one's lifetime to maintain visual benefits. Additionally, some patients do not benefit from established treatments. Strategies providing long-term suppression of inappropriate ocular angiogenesis are therefore needed, and gene therapy offers a potential powerful technique. This study aimed to develop a strategy based on RNA interference (RNAi) for the sustained attenuation of VEGF. We designed a panel of anti-VEGF short hairpin RNAs (shRNA), and based on the most potent shRNAs, microRNA (miRNA)-mimicked hairpins were developed. We demonstrated an additive VEGF silencing effect when we combined the miRNAs in a tricistronic miRNA cluster. To meet the requirements for development of medical treatments for AMD with long-term effects, the shRNA/miRNA is expressed from vectors based on adeno-associated virus (AAV) or lentivirus (LV). Both vector systems have been found superior in terms of transduction efficiency and persistence in gene expression in retinal cells. The capacity of AAV-encoded RNAi effector molecules to silence endogenous VEGF gene expression was evaluated in mouse models, including the model of laser-induced choroidal neovascularization (CNV), and we found that subretinal administration of self-complementary (sc)-AAV2/8 encoding anti-VEGF shRNAs can impair vessel formation. In parallel, a significant reduction of endogenous VEGF was demonstrated following injection of scAAV2/8 vectors expressing multiple anti-VEGF miRNAs into murine hind limb muscles. Furthermore, in an ongoing project we have designed versatile, multigenic LV vectors with combined expression of multiple miRNAs and proteins, including pigment epithelium-derived factor (PEDF), a multifunctional, secreted protein that has anti-angiogenic and neurotrophic functions. Co-expression of miRNAs and proteins from a single viral vector increases safety by minimizing the viral load necessary to obtain a therapeutic effect and thereby reduces the risk of insertional mutagenesis as well as the immune response against viral proteins. Our results show co-expression of functional anti-VEGF-miRNAs and PEDF in cell studies, and in vivo studies reveal an efficient retinal pigment epithelium (RPE)-specific gene expression following the incorporation of the vitelliform macular dystrophy 2 (VMD2) promoter, demonstrating the potential applicability of our multigenic LV vectors in ocular anti-VEGF gene therapy, including combination therapy for treatment of exudative AMD. In conclusion, these highly promising data clearly demonstrate that viral-encoded RNAi effector molecules can be used for the inhibition of neovascularization and will, in combination with the growing interest of applying DNA- or RNA-based technologies in the clinic, undoubtedly contribute to the development of efficacious long-term gene therapy treatment of intraocular neovascular diseases.