Embryology, anatomy, and surgical applications of the preperitoneal space

The Preperitoneal Space in Hernia Repair

The preperitoneal spaces relevant for incisional hernia repair and minimally invasive groin hernia repair are described in terms of surgical anatomy. Emphasis is put on the transversalis fascia and the urogenital fascia and its extensions, the vesicoumbilical fascia, and the spermatic sheath of Stoppa procedure. Steps in hernia surgery where these structures are relevant are reviewed.

Salivary parameters alterations after early exposure to environmental methylmercury: A preclinical study in offspring rats

BACKGROUND

Methylmercury (MeHg) is still considered a global pollutant of major concern; thus, it becomes relevant to investigate and validate alternative diagnostic methods to track early-life human exposure. This study aimed to evaluate the salivary parameters and to characterize potential mechanisms of oxidative damage on the salivary glands (SG) of offspring rats after pre- and postnatal environmental-experimental MeHg exposure.

METHODS

Pregnant Wistar rats were daily exposed to 40 μg/kg MeHg during both gestational and lactation periods. Then, the saliva of offspring rats was analyzed in terms of flow rate, amylase activity, and total protein concentration. The SG of the offspring rats were dissected to perform the oxidative biochemistry analyses of antioxidant capacity against peroxyl radicals (ACAP), lipid peroxidation (LPO), and nitrite levels.

RESULTS

Exposure to MeHg significantly decreased the ACAP, increased LPO and nitrite levels, decreased salivary flow rate, amylase activity, and total protein concentration.

CONCLUSION

Saliva analyses can predict damages induced by early-life MeHg exposure and may be used as an auxiliary diagnostic method.

Methylmercury-Induced Toxicopathologic Findings in Salivary Glands of Offspring Rats After Gestational and Lactational Exposure

Methylmercury (MeHg) is one of the main global pollutants. The vulnerability of fetus and newborn to MeHg-induced changes is extensively reported, making relevant investigation possible for alternative sample matrix for human biological monitoring for at this stage of life. This study aimed to characterize tissue change effects of environmental-experimental MeHg on salivary glands of offspring rats after pre- and postnatal exposure. For this, pregnant Wistar rats were orally exposed to MeHg (40 μg/kg BW/day) or only vehicle (control group), from the gestational period to the end of the lactation period. Salivary glands (SG) were collected from the offspring to analyze possible Hg levels and main findings by histopathological evaluations and CK19 and α-SMA immunostaining. The results indicated that Hg levels in SG of intoxicated offspring were associated with histologic abnormalities, such as acinar atrophy and an increase in the intercellular matrix among the acini, as well as damages in the architecture of epithelium and myoepithelial cells, evidenced by a decrease in immunostaining area. Thus, this is the first study to show in the literature the toxicopathologic findings on SG of offspring after pre- and postnatal exposure to MeHg. Moreover, it presents the SG as an attractive target to futures studies, mainly in children exposed to environmentally relevant doses.

Revision Hip Arthroplasty in Patient with Acetabulum Migration into Subperitoneal Space-A Case Report

Revision hip arthroplasty procedures have been extensively discussed in the literature. At the same time, discussions of the management of acetabular component protrusion into the pelvic cavity, and, more specifically, the subperitoneal space, necessitating an additional abdominal approach for the revision arthroplasty, have only been published as case reports and descriptions of transperitoneal approaches have been even rarer. This paper presents the case of a 63-year-old female patient in whom a peritoneal approach was necessary to access a migrated acetabular component. The outcome of the treatment, which represented a complex orthopedic and general surgical problem, was good. We believe that the complexity of revision hip arthroplasty in patients with protrusion of the acetabular component together with the head and proximal part of the stem of the implant into subperitoneal space calls for a careful re-analysis of the category of Type III bony acetabulum defects according to Paprosky, where the recognition of two subtypes would facilitate analysis of such cases.

Imaging in gynecological disease (19): clinical and ultrasound features of extragastrointestinal stromal tumors (eGIST)

OBJECTIVE

To describe the clinical and sonographic characteristics of extragastrointestinal stromal tumors (eGISTs).

METHODS

This was a retrospective multicenter study. The data of patients with a histological diagnosis of eGIST who had undergone preoperative ultrasound examination were retrieved from the databases of nine large European gynecologic oncology centers. One investigator from each center reviewed stored images and ultrasound reports, and described the lesions using the terminology of the International Ovarian Tumor Analysis and Morphological Uterus Sonographic Assessment groups, following a predefined ultrasound evaluation form. Clinical, surgical and pathological information was also recorded.

RESULTS

Thirty-five women with an eGIST were identified; in 17 cases, the findings were incidental, and 18 cases were symptomatic. Median age was 57 years (range, 21-85 years). Tumor marker CA 125 was available in 23 (65.7%) patients, with a median level of 23 U/mL (range, 7-403 U/mL). The vast majority of eGISTs were intraperitoneal lesions (n = 32 (91.4%)); the remaining lesions were retroperitoneal (n = 2 (5.7%)) or preperitoneal (n = 1 (2.9%)). The most common site of the tumor was the abdomen (n = 23 (65.7%)), and less frequently the pelvis (n = 12 (34.3%)). eGISTs were typically large (median largest diameter, 79 mm) solid (n = 31 (88.6%)) tumors, and were less frequently multilocular-solid tumors (n = 4 (11.4%)). The echogenicity of solid tumors was uniform in 8/31 (25.8%) cases, which were all hypoechogenic. Twenty-three solid eGISTs were non-uniform, either with mixed echogenicity (9/23 (39.1%)) or with cystic areas (14/23 (60.9%)). The tumor shape was mainly lobular (n = 19 (54.3%)) or irregular (n = 10 (28.6%)). Tumors were typically richly vascularized (color score of 3 or 4, n = 31 (88.6%)) with no shadowing (n = 31 (88.6%)). Based on pattern recognition, eGISTs were usually correctly classified as a malignant lesion in the ultrasound reports (n = 32 (91.4%)), and the specific diagnosis of eGIST was the most frequent differential diagnosis (n = 16 (45.7%)), followed by primary ovarian cancer (n = 5 (14.3%)), lymphoma (n = 2 (5.7%)) and pedunculated uterine fibroid (n = 2 (5.7%)).

CONCLUSIONS

On ultrasound, eGISTs were usually solid, non-uniform pelvic or abdominal lobular tumors of mixed echogenicity, with or without cystic areas, with rich vascularization and no shadowing. The presence of a tumor with these features, without connection to the bowel wall, and not originating from the uterus or adnexa, is highly suspicious for eGIST. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Preliminary results of robotic inguinal hernia repair following its introduction in a single-center trial

AIM

Robotic surgery using the da Vinci system has markedly increased worldwide. However, robotic inguinal hernia repair remains unpopular outside the United States. We introduced and evaluated a robotic transabdominal preperitoneal repair (R-TAPP) technique for inguinal hernia in our hospital.

METHODS

First, we designed a task protocol according to the surgical results of 388 laparoscopic TAPP (L-TAPP) procedures performed during the 4 years prior to introducing R-TAPP. Our task protocol included several time limitations during a step-wise procedure: creating the peritoneal flap (<60 minutes), mesh placement with fixation (<30 minutes), and peritoneal suture closure (<30 minutes) under experienced supervision. We investigated the preliminary clinical results of R-TAPP performed by a single operator between December 2018 and January 2020.

RESULTS

We identified 27 lesions in 20 patients (unilateral in 13 and bilateral in seven). According to the Japan Hernia Society Classification, our cohort included eight type I, five type II, and seven bilateral hernias (nine type I, four type II, and one type IV). The median operation time was 124 minutes (range, 81-164 minutes), and the median console operation time was 85 minutes (range, 50-132). The median time required for the peritoneal incision was 30 minutes (range, 18-54 minutes), that for mesh placement (including tucking) was 13 minutes (range, 7-27 minutes), and that for peritoneal suturing was 9 minutes (range, 3-20 minutes).

CONCLUSION

Our preliminary results suggest that our task protocol for R-TAPP is feasible. However, refinement of our task protocol is essential for standardization.

An extraperitoneal approach for complex flank, iliac, and lumbar hernia

PURPOSE

The aim of this paper is to propose our four-step technique, an open extraperitoneal approach for complex flank, lumbar, and iliac hernias.

METHODS

A big polypropylene mesh is placed, covering and reinforcing all the lateral abdominal wall in an extraperitoneal space. Its borders are retroxiphoid fatty triangle and the costal arch cranially and the retropubic space caudally, psoas muscle, and paravertebral region posteriorly and contralateral rectus muscle medially. Mesh dimensions do not depend from the defect size, but prosthesis has to cover all the lateral abdominal wall.

RESULTS

No major complications have been reported. The mean length of stay is 4.8 days (range 3-11). Mean follow-up is 44.8 months (range 5-92). One recurrence (4.5%) has been reported at the 1-year clinical evaluation.

CONCLUSION

In conclusion, we believe that regardless size and location of the defect, every complex lateral hernia requires the same extensive repair because of the critical anatomy of the region with a big medium-heavyweight polypropylene mesh placed in an extraperitoneal plane, the only one that allows adequate covering of the visceral sac. Our technique is a safe, feasible, and reproducible treatment for this challenging surgical problem.

Feasibility and continence outcomes of extended prostatic urethral preservation during robot-assisted radical prostatectomy

BACKGROUND

The prostatic urethra is conventionally resected during robot-assisted radical prostatectomy (RARP). We describe the technical feasibility and urinary continence outcomes of extended prostatic urethral preservation (EPUP) during RARP.

METHODS

A single surgeon at a National Comprehensive Cancer Network institute performed 48 consecutive RARP operations using EPUP from March 2014 to March 2016, during which time 177 conventional non-EPUP RARP operations were performed by other surgeons. Prior to this period, the EPUP surgeon had performed 17 non-EPUP RARP operations over 15 months. Total intracorporeal urethral length (IUL) preserved during EPUP was measured intraoperatively. Associations of EPUP and IUL with continence recovery rates and/or times were tested in Fisher's exact and log rank univariate analyses and Cox logistic regression multivariable analyses.

RESULTS

Median IUL preserved during EPUP was 4.0 cm (range 2.5-6.0 cm), and urethral dissections typically spanned the prostatic apex to mid-gland or base. Seven-week continence rates were significantly higher with versus without EPUP. EPUP patient rates of using 0 or 0-1 pads per day immediately after catheter removal were 19% and 35%, respectively. These rates increased significantly (53% and 76%, respectively), as did the IUL preserved (median 5.0 cm), among more recent EPUP patients (n = 17), which suggested a learning curve. In multivariable analyses including all patients, an EPUP approach was an independent predictor of faster continence recovery. In multivariable analyses of the EPUP subset, a longer IUL preserved was independently associated with faster continence recovery. No EPUP patient had a urethral fossa positive margin, and apical positive margins were similarly infrequent among EPUP and non-EPUP patients.

CONCLUSIONS

EPUP is technically feasible during RARP and associated with faster continence recovery. Future investigation into the generalizability of these findings and the oncologic safety of EPUP is warranted.

Imaging of inguinal-related groin pain in athletes

Inguinal canal-related groin pain is common in athletes and may involve numerous structures such as the conjoint tendon and the transversalis fascia. Ultrasound is the only dynamic tool that shows the passage of preperitoneal fat at the level of the Hesselbach triangle and allows excluding true inguinal hernias. Fascia transversalis bulging and inguinal ring dilatation may also be described. MRI assesses injuries of rectus abdominis and adductor longus enthesis and osteitis symphysis but its accuracy for the diagnosis of inguinal-related groin pain remains debated.

How robotic surgery is changing our understanding of anatomy

The most recent revolution in our understanding and knowledge of the human body is the introduction of new technologies allowing direct magnified vision of internal organs, as in laparoscopy and robotics. The possibility of viewing an anatomical detail, until now not directly visible during open surgical operations and only partially during dissections of cadavers, has created a ‘new surgical anatomy’. Consequent refinements of operative techniques, combined with better views of the surgical field, have given rise to continual and significant decreases in complication rates and improved functional and oncological outcomes. The possibility of exploring new ways of approaching organs to be treated now allows us to reinforce our anatomical knowledge and plan novel surgical approaches. The present review aims to clarify some of these issues.

Rives Technique for the Primary Larger Inguinal Hernia Repair: A Prospective Study of 1000 Repairs

Objective

We report a prospective study of repairs using the Rives technique of the more difficult primary inguinal hernias, focusing on the immediate post-operative period, clinical recurrence, testicular atrophy, and chronic pain. A mesh placed in the preperitoneal space can reduce recurrences and chronic pain.

Methods

For the larger primary inguinal hernias (Types 3, 4, 6, and some 7), we favour preperitoneal placement of a mesh, covering the myopectineal orifice by means of a transinguinal (Rives technique) approach. The Rives technique was performed on 943 patients (1000 repairs), preferably under local anaesthesia plus sedation in ambulatory surgery.

Results

The mean operative time was 31.8 min. Pain assessment after 24 h with an Andersen scale and a categorical scale gave two patients with intense pain on the Andersen scale, and four patients who thought their state was bad. Surgical wound complications were below 1%, and urinary retention was 1.2% mostly associated with spinal anaesthesia and, in one case, bladder perforation. There was spermatic cord and testicular oedema with some degree of orchitis in 17 patients. The clinical follow-up of 849 repairs (86.4%), mean (range) 30.0 (12–192) months, gave five recurrences (0.6%), three cases (0.4%) of testicular atrophy, and 37 (4.3%) of post-operative chronic pain (8 patients with visual analogue scale of 3–10).

Conclusions

The Rives technique requires a sound knowledge of inguinal preperitoneal space anatomy, but it is an excellent technique for the larger and difficult primary inguinal hernias, giving a low rate of recurrences and chronic pain.

US of the Inguinal Canal: Comprehensive Review of Pathologic Processes with CT and MR Imaging Correlation

Ultrasonography (US) has a fundamental role in the initial examination of patients who present with symptoms indicating abnormalities of the inguinal canal (IC), an area known for its complex anatomy. A thorough understanding of the embryologic and imaging characteristics of the contents of the IC is essential for any general radiologist. Moreover, an awareness of the various pathologic conditions that can affect IC structures is crucial to preventing misdiagnoses and ensuring optimal patient care. Early detection of IC abnormalities can reduce the risk of morbidity and mortality and facilitate proper treatment. Abnormalities may be related to increased intra-abdominal pressure, which can result in development of direct inguinal hernias and varicoceles, or to congenital anomalies of the processus vaginalis, which can result in development of indirect hernias and hydroceles. US is also helpful in assessing postoperative complications of hernia repair, such as hematoma, seroma, abscess, and hernia recurrence. In addition, it is often the modality initially used to detect neoplasms arising from or invading the IC. US is an important tool in the examination of patients suspected of having undescended testes or posttraumatic testicular retraction and is essential for the examination of patients suspected of having torsion or infectious inflammatory conditions of the spermatic cord. Online supplemental material is available for this article. ^©RSNA, 2016.

[A rare cause of acute small bowel obstruction: incarcerated Spieghelian hernia. Case-report and literature review]

A 73-year-old man, who previously underwent laparotomy for pancreatic adenocarcinoma, was admitted in the emergency room for acute small bowel obstruction related to a strangulated Spieghelian hernia. On CT-scan, the hernia was located at the lateral border of the right rectus abdominis muscle below the external oblique muscle, among the transverse abdominis and internal oblique muscles layers. Spieghelian hernias (or hernia of the linea semilunaris) often occur at the level of a weak spot where the linea accurata crosses the linea semilunaris, when the posterior layer of the rectus gain changes its conformation. This weak spot is limited underneath by the inferior epigastric artery. When examining a patient with a previous history of laparotomy presenting with acute small bowel obstruction, it is mandatory to exclude a possible strangulated Spieghelian hernia before concluding to postoperative intra-abdominal adhesions. Spieghelian hernias are asymptomatic in approximately 90% of cases but entail a high risk of strangulation. Consequently, herniorrhaphy through a local approach route or open/laparoscopic mesh repair is always required.

An evidence-based approach for laparoscopic inguinal hernia repair: lessons learned from over 1,000 repairs

In this educational article, we aim to provide a literature review on laparoscopic anatomy of the inguinal region. We share the lessons learnt from the 1,194 laparoscopic hernia operations we have performed in 16 years of experience, trying to provide an anatomical and physiological basis for surgeons. The current study reports a personal experience with a transabdominal preperitoneal (TAPP) hernioplasty procedure. A literature review using the keywords "hernia," "laparoscopic approach," and "hernia repair" was performed using the electronic biomedical database PubMed, Medline Extra, Embase, Biosis, Science Citation Index, Ovid and text books. Between January 1994 and December 2010, a total of 1,194 patients, males and females (average age, 56.7 years), underwent laparoscopic TAPP inguinal hernia repair. Following reduction of the hernia sac and creation of the preperitoneal flap, a polypropylene mesh (10 × 16) and four spiral tacks were placed. TAPP is easy to learn and perform. Through this approach, a much better view from the inguinal anatomy is achieved, and the procedure also offers a brief learning curve. Our patients reported minimal postoperative pain and returned to work after 5-10 days, which is in accordance with the general anesthesia series. During the follow-up period, 10% of seromas, 3% of scrotal hematomas, 1% of hemorrhages, and 3% of recurrent hernias were observed. It should be emphasized that we have not observed abscess formation or acute infection related to the presence of mesh.

Obturator Hernia Revisited: Surgical Anatomy, Embryology, Diagnosis, and Technique of Repair

Obturator hernia is the protrusion of intraperitoneal or extraperitoneal organs or tissues through the obturator canal. The first case was published by de Ronsil in 1724. Obturator hernia is more common in older malnourished women due to loss of supporting connective tissue and the wider female pelvis. The hernia sac usually contains small bowel, especially ileum. It may follow the anterior or posterior division of the obturator nerve. In most cases, obturator hernia presents with intestinal obstruction of unknown cause. It may present with obturator neuralgia, as a palpable mass or, in cases of bowel necrosis, as ecchymosis of the thigh. A correct diagnosis is made in 20 to 30 per cent of cases. CT scan is considered the gold standard for diagnosis, whereas ultrasonography, contrast studies, herniography and plain films are less specific. Surgery is the only treatment option for obturator hernia. Hesitancy to intervene surgically for chronically ill patients results in high mortality. Transabdominal approach is indicated in cases of complete bowel obstruction or suspected peritonitis. The extra-abdominal approach is used in preoperatively diagnosed cases and in absence of bowel strangulation. The laparoscopic approach is minimally invasive and effectively reduces morbidity. The defect is closed using sutures, tissue flaps, or prosthetic mesh.

Epidermoid cyst of round ligament: case report and review of literature

Round ligament tumors are rare, and when found are typically leiomyomas. Herein is described a case of an epidermoid cyst of the round ligament, previously reported only once in the literature. Epidermoid cysts are similar to dermoid tumors but have only an epidermis-lined structure filled with keratin. Management included laparoscopic removal of the tumor. The patient's recovery was uneventful.

Surgical Anatomy of the Retroperitoneal Spaces–Part I: Embryogenesis and Anatomy

Embryologically, the retroperitoneal (extraperitoneal) connective tissue includes three strata, which respectively form the internal fascia lining of the body wall, the renal fascia, and the covering of the gastrointestinal viscera. All organs, vessels, and nerves, that lie on the posterior abdominal wall, along with their tissues and surrounding connective and fascial planes, are collectively referred to as the retroperitoneum. The retroperitoneal space is the area of the posterior abdominal wall that is located between the parietal peritoneum and the fascia. Within the greater retroperitoneal space, there are also several small spaces, or subcompartments. Loose connective tissue and fat surround the anatomic entities, and, to a variable degree, occupy the subcompartments. The multilaminar thoracolumbar (lumbodorsal) fascia begins at the occipital area and terminates at the sacrum.

Laparoscopic Inguinal Hernia Repair

As a consequence of the development of laparoscopic cholecystectomy in the late 1980s, diagnostic and therapeutic laparoscopy has now become an integral part of the average general surgeon's practice. Many conventional operations have been successfully adapted for the laparoscopic approach. A laparoscopic operation is unquestionably the surgical procedure of choice for gastroesophageal reflux disease and removal of the gallbladder, spleen, or adrenal gland unless specific contraindications are present. However, the value of laparoscopic techniques for other operations remains controversial within the surgical community. Laparoscopic inguinal herniorrhaphy (LIH) is a case in point. Frequent reanalysis of the controversial procedures such as laparoscopic herniorrhaphy is especially important because videoscopic operations remain in their developmental stages and thus continue to evolve. With this in mind, the purpose of this review was to examine the current state of the art of laparoscopic inguinal herniorrhaphy in relationship to its conventional counterparts.

The femoral nerve in the repair of inguinal hernia: well worth remembering

Injury to the nerves after inguinal hernia surgery is uncommon. The femoral nerve may be damaged by suture or staples, tissue scar entrapment, local anesthesia blockade or direct compression. We present a case of a transient lesion of the femoral nerve after mesh hernioplasty for a re-recurrent inguinal hernia, confirmed by radiological studies, electrophysiology and clinical recovery. The diagnosis, mechanism of injury and surgical approach are reviewed. Surgery to a recurrent hernia may be underestimated. The role of electromyography nerve conducting studies is emphasized insisting on the importance of clinical evolution for the successful management of these infrequent injuries.

Analysis of clustered matched-pair data for a non-inferiority study design

Hypothesis testing of matched-pair data has been adapted for equivalence (one- and two-sided) study designs; however, a statistical problem arises when more than one measurement is recorded for each study subject. Ignoring the correlation between the repeated measurements per subject may underestimate the standard error of the parameter estimate. A method of testing for non-inferiority or equivalence of clustered matched-pair data is not yet available. This paper proposes a Wald-type test statistic for a non-inferiority hypothesis and applies it to the comparison of two diagnostic procedures.