The analgesic effect of transversalis fascia plane block after caesarean section under spinal anaesthesia with intrathecal morphine: a randomised controlled trial.

We aimed to test whether bilateral injection of bupivacaine 0.25% in the transversalis fascia plane reduced 24 h opioid dose after singleton caesarean section, under spinal anaesthesia with intrathecal morphine, compared with saline 0.9% injectate. We allocated randomly 52 women to bilateral injection of 20 ml saline 0.9% on arrival in the post-anaesthesia care unit and 54 women to bilateral injection of 20 ml bupivacaine 0.25% (with adrenaline 2.5 µg.ml-1 ). Mean (SD) cumulative morphine equivalent opioid dose 24 h after saline injection was 32.3 (28.3) mg and 18.7 (20.2) mg after bupivacaine injection, a mean (95%CI) difference of 13.7 (4.1-23.2) mg (p = 0.006). Median (IQR [range]) time to first postoperative opioid dose was 3.0 (1.5-10.3 [0.0-57.4]) h after saline 0.9% and 8.2 (2.7-29.6 [0.2-55.4]) h after bupivacaine 0.25% (p = 0.054). Transversalis fascia plane with bupivacaine 0.25% with adrenaline reduced postoperative pain at rest during 48 h (0-10-point scale) by a mean (95%CI) of 0.9 (0.2-1.6) points (p = 0.013) and on movement by 1.2 (0.4-2.1) points (p = 0.004). We conclude that transversalis fascia plane bupivacaine 0.25% with adrenaline reduces pain and opioid dose after caesarean section compared with saline 0.9%.

Analgesic effects of different concentrations of ropivacaine in transversalis fascia plane block during laparotomy.

OBJECTIVE: To explore the analgesic effects of different concentrations of ropivacaine in transversalis fascia plane (TFP) block during laparotomy. METHODS: Ninety patients who underwent laparotomy admitted to our hospital from March 2019 to March 2020 were selected as the study subjects and were divided equally into a low concentration group, a medium concentration group, and a high concentration group according to the randomized grouping method. The low concentration group adopted 0.4% ropivacaine 40 ml, the medium concentration group was given 0.5% ropivacaine 40 ml, and the high concentration group was given 0.6% ropivacaine 40 ml. The hemodynamic indexes and the incidence of adverse reactions in the two groups were compared. The Numerical Rating Scale (NRS) was used to assess the postoperative pain in the three groups, the Bruggrmann comfort scale (BCS) was used to assess the comfort level in the three groups, and the Mini-mental State Examination (MMSE) was used to evaluate the postoperative cognitive function of the three groups of patients. RESULTS: The mean artery pressure (MAP) and heart rate (HR) levels at T1 and T2 were significantly lower in the medium concentration group than in the other two groups (P < 0.05). The low concentration group had a significantly higher NRS score at T2 than the medium concentration group and the high concentration group (P < 0.05). A significantly higher BCS score was observed in the high concentration group than the other two groups (P < 0.05). There were significantly higher Ramsay scores and MMSE scores in the medium concentration group than in the low concentration and high concentration groups (P < 0.05). The overall incidence of adverse reactions of the high concentration group was significantly higher than that of the low concentration group (P < 0.05), but showed similar results with the medium concentration group. CONCLUSION: The medium concentration group exhibits a better analgesic effect than the low concentration group and higher safety than the high concentration group. Therefore, the use of medium concentration ropivacaine in TFP block may provide a referential basis for clinical treatment.

Urogenital fascia anatomy study in the inguinal region of 10 formalin-fixed cadavers: new understanding for laparoscopic inguinal hernia repair.

PURPOSE: To investigate the urogenital fascia (UGF) anatomy in the inguinal region, to provide anatomical guidance for laparoscopic inguinal hernia repair (LIHR). METHODS: The anatomy was performed on 10 formalin-fixed cadavers. The peritoneum and its deeper fascial tissues were carefully dissected. RESULTS: The UGF's bilateral superficial layer extended and ended in front of the abdominal aorta. At the posterior axillary line, the superficial layer medially reversed, with extension represented the UGF's deep layer. The UGF's bilateral deep layer medially extended beside the vertebral body and then continued with the transversalis fascia. The ureters, genital vessels, and superior hypogastric plexus moved between both layers. The vas deferens and spermatic vessels, ensheathed by both layers, moved through the deep inguinal ring. From the deep inguinal ring to the midline, the superficial layer extended to the urinary bladder's posterior wall, whereas the deep layer extended to its anterior wall. Both layers ensheathed the urinary bladder and extended along the medial umbilical ligament to the umbilicus and in the sacral promontory, extended along the sacrum, forming the presacral fascia. The superficial layer formed the rectosacral fascia at S4 sacral vertebra, and the deep layer extended to the pelvic diaphragm, terminating at the levator ani muscle. CONCLUSION: The UGF ensheaths the kidneys, ureters, vas deferens, genital vessels, superior hypogastric plexus, seminal vesicles, prostate, and urinary bladder. This knowledge of the UGF's anatomy in the inguinal region will help find correct LIHR targets and reduce bleeding and other complications.

Repair of the Severe Muscle Aponeurotic Abdominal Laxity with Alloplastic Mesh in Aesthetic Abdominoplasty.

BACKGROUND: Abdominoplasty is the most frequently performed surgical procedure for body contour; in our experience, we have observed some patients with prominent bulging that is difficult to treat and that presents results that are unsatisfactory or have recurrences to conventional treatments. This leads us to carry out an analysis of the elements responsible for the containment and abdominal format. We determined that it may be due to an inability of an important sagging aponeurotic muscle of primary origin to support the abdomen and could be caused by predisposing factors. For these specific cases, we developed a treatment proposing the use of a mesh. METHODS: We present these cases over a period of 24 years. Fourteen patients were treated with primary and secondary abdominoplasties. The abdominal wall reinforcement was performed by placing polypropylene mesh at the sub-muscular plane, fixed with U-stitches on the fascia transversalis, seeking to strengthen the muscle and the fascia transversalis. RESULTS: The results were satisfactory after long-term observation, gaining resolution of the abdominal bulges. Only two complications occurred; the presence of localized chronic pain and the appearance of umbilical fistula. DISCUSSION: We emphasize the importance of avoiding unnecessary interventions in patients with marked bulging, associated with inability of abdominal restraint. We only consider its indications in patients with conventional recurrence treatment, also identifying the predisposing factors, the knowledge of the abdominal anatomy, the muscular dynamics of the abdomen and understanding its indication in these specific cases of difficult treatment. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The initial experience of robot-assisted transabdominal transversalis fascial and preperitoneal repair for small ventral hernia.

PURPOSE: Despite the widespread of ventral hernia repairs globally, the approach method, dissection planes, defect closure, and the choice and placement layer of mesh are an ongoing debate. We reported the details of surgical techniques, safety and feasibility for robot-assisted transabdominal transversalis fascial and preperitoneal repair (R-TATFPP) for small ventral hernia. METHODS: This study included 5 cases of R-TATFPP repair among 22 cases performed by robot-assisted ventral hernia repair from 2018 to 2023 with the approval of the Institutional Review Board at St. Luke's International University and clinical ethical committee at St. Luke's International Hospital (19-R147, 22-012). RESULTS: There were four males and one female, with mean age of 64.4 ± 10.0 years, inclusive of two umbilical and three incisional hernias. Mean height, weight, body mass index (BMI), hernia defect length, width, operation time, console time, and hospital stay were 171.2 ± 11.8 cm, 82.4 ± 13.4 kg, 28.0 ± 2.1 kg/m2, 2.8 ± 1.4 cm, 3.0 ± 1.3 cm, 180 min, 133.8 min, and 2.4 days, respectively. No conversion nor complication was observed except for one acute urinary retention. CONCLUSION: Robot-assisted transversalis fascial and preperitoneal repair was safe and feasible for small ventral hernia with the minimal disruption to the abdominal wall architecture and structures.

Preoperative CT findings predict the development of metachronous contralateral inguinal hernia after unilateral inguinal hernia repair: a single-center retrospective cohort study.

PURPOSE: To identify potential clinical and preoperative CT risk factors that can predict the development of metachronous contralateral inguinal hernia (MCIH) after unilateral inguinal hernia repair (IHR). METHODS: This study included unilateral inguinal hernia patients seen from 2016 to 2019 who underwent CT and subsequent IHR and had at least five years of follow-up. Preoperative CT scans were retrospectively reviewed for the presence of asymmetric spermatic cord fat and weakness of the transversalis fascia. The correlations of each CT feature and other clinical characteristics with the development of MCIH were calculated. The Kaplan-Meier model and multiple logistic regression were used to evaluate the associations among CT features, clinical variables and MCIH. RESULTS: A total of 677 male patients aged > 40 years were included in the study cohort. After more than 5 years of follow-up, 162 patients developed MCIH, representing an incidence of 23.9%. Patients with radical prostatectomy or peritoneal dialysis [P < 0.0001, HR 4.189 (95% CI 2.369 to 7.406)], primary left-sided IHR [P = 0.0032, HR 1.626 (95% CI 1.177 to 2.244)], and direct, femoral or pantaloon hernias were predisposed to MCIH. Asymmetric spermatic cord fat [P = 0.0002, HR 1.203 (95% CI 0.8785 to 1.648)] and weakness of the transversalis fascia [P < 0.0001, HR 7.914 (95% CI 5.666 to 11.05)] on preoperative CT were also identified as risk facts and demonstrated to be independent predictive factors for MCIH development. CONCLUSION: Asymmetric spermatic cord fat and weakness of the transversalis fascia were predictive factors for MCIH development. For decision making regarding prophylactic contralateral IHR at the time of index surgery, preoperative CT findings as well as clinical characteristics should be considered.

Understanding the Anatomy of Retroperitoneal Interfascial Space: Implications for Regional Anesthesia.

BACKGROUND: Fascial plane block techniques have evolved considerably in recent years. Unlike the conventional peripheral nerve block methods, the fascial plane block's effect can be predicted based on fascial anatomy and does not require a clear vision of the target nerves. The anatomy of the retroperitoneal interfascial space is complex, since it comprises multiple compartments, including the transversalis fascia (TF), the retroperitoneal fasciae (RF), and the peritoneum. For this reason, an in-depth, accurate understanding of the retroperitoneal interfascial space's anatomical characteristics is necessary for perceiving the related regional blocks and mechanisms that lie underlie the dissemination of local anesthetics (LAs) outside or within the various retroperitoneal compartments. OBJECTIVES: This review aims to summarize the retroperitoneum's anatomical characteristics and elucidate the various communications among different interfascial spaces as well as their clinical significance in regional blocks, including but not limited to the anterior quadratus lumborum block (QLB), the fascia iliaca compartment block (FICB), the transversalis fascia plane block (TFPB), and the preperitoneal compartment block (PCB). STUDY DESIGN: This is a narrative review of pertinent studies on the use of retroperitoneal spaces in regional anesthesia (RA). METHODS: We conducted searches in multiple databases, including PubMed, MEDLINE, and Embase, using "retroperitoneal space," "transversalis fascia," "renal fascia," "quadratus lumborum block," "nerve block," and "liquid diffusion" as some of the keywords. RESULTS: The anatomy of the retroperitoneal interfascial space has a significant influence on the injectate spread in numerous RA blocking techniques, particularly the QLB, FICB, and TFPB approaches. Furthermore, the TF is closely associated with the QLB, and the extension between the TF and iliac fascia offers a potential pathway for LAs. LIMITATIONS: The generalizability of our findings is limited by the insufficient number of randomized controlled trials (RCTs). CONCLUSIONS: Familiarity with the anatomy of the retroperitoneal fascial space could enhance our understanding of peripheral nerve blocks. By examining the circulation in the fascial space, we may gain a more comprehensive understanding of the direction and degree of injectate diffusion during RA as well as the block's plane and scope, possibly resulting in effective analgesia and fewer harmful clinical consequences.

Primary Tissue Repair for Inguinal Hernias: The Shouldice Repair Technique and Patient Selection.

It is estimated that approximately one in four men and one in 20 women will develop an inguinal hernia over the course of their lifetime. A non-mesh inguinal hernia repair via the Shouldice technique is a unique approach that necessitates dissection of the entire groin region as well as careful assessment for any secondary hernias. Subsequently, a pure tissue laminated closure allows the repair to be performed without tension. Herein, the authors describe a brief overview of inguinal hernias and discuss the relevant patient evaluation, operative steps of the Shouldice procedure, and postoperative considerations.

Role of Collagen in the Etiology of Inguinal Hernia Patients: A Case-Control Study.

Introduction Technical faults are no longer accepted as the sole reason for recurrence following inguinal hernia (InH) repairs. Medical literature has been studied to find any contributing factors and collagen has emerged as a promising marker. Owing to their long half-lives, it has been found to best reflect the process of scarring, which is central to ensuring the formation of a proper fibrous tissue that incorporates the mesh with the abdominal wall. Methods Sixty participants were divided into two groups. The case group were patients diagnosed with InH and the control group had patients undergoing abdominal surgeries for indications other than abdominal wall hernias. A 0.5x0.5cm specimen of skin and transversalis fascia were biopsied and subsequently stained to determine the amount of collagen I and III. Results Collagen I, collagen III and the ratio of collagen I to III was measured. Collagen I was normal in the skin of both groups but decreased in transversalis fascia of cases. Collagen III was found to be normal in transversalis fascia of both cases and controls, but increased in the skin of cases. Ratio of collagen I to III was decreased in both skin and transversalis fascia of cases. Statistical analysis was carried out using an unpaired t-test, non-parametric Mann-Whitney test, ANOVA and chi-square test. Conclusions Our study has reported that in patients with inguinal hernia, collagen III or immature collagen is increased in skin and collagen I or mature collagen is decreased in the transversalis fascia. The ratio of collagen I/III is decreased in both skin and transversalis fascia.

Comparison of ultrasound-guided transversalis fascia and posterior transversus abdominis plane block for postoperative analgesia following caesarean delivery: A double-blinded randomised controlled trial.

Background and Aims: Posterior-transversus abdominus plane (TAP) block and transversalis fascia plane (TFP) block have been used for postoperative analgesia following caesarean delivery. We compared the analgesic efficacy of the TAP vs TFP plane blocks in patients undergoing elective caesarean delivery. Methods: We randomised 90 women undergoing caesarean delivery under spinal anaesthesia to receive either a posterior-TAP (Group-TAP), TFP (Group-TFP) or no block (Group-C) postoperatively. The primary objective was the postoperative analgesic requirements. Secondary objectives were duration of analgesia, pain scores and infra-umbilical sensory loss, which were recorded at specific intervals for 24 h. Statistical analysis was carried out using Statistical Package for Social Sciences version 16.0 software. Results: The patients requiring one, two or nil rescue analgesics were comparable between the interventions and the control (P = 0.32). The duration of analgesia was longer in Group-TAP when compared to Group-C, 4.76 (1.2) vs. 6.89 (2.4); P < 0.001, whereas Group-TFP, 5.64 (2.1) h, was not significantly different from Group-C. The static pain score in Group-TAP was significantly less than that in Group-C at 4 h and beyond 12 h (P < 0.001), whereas Group-TFP was comparable with Group-C at all time points except at 4 h and 24 h (P = 0.002). Only Group-TAP demonstrated midline infraumbilical sensory loss. Conclusion: TAP and TFP blocks did not decrease the rescue analgesic requirement compared with the control group. The posterior-TAP block prolonged the duration of analgesia by 2 h, maintained the median static pain score at 0 beyond 12 h, and demonstrated sensory loss at the infraumbilical dermatomes.

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.

Inflatable penile prosthesis reservoir placement-Are we ready for a paradigm change?

In 2002, Steve Wilson pioneered new procedures for alternative placement of reservoirs for inflatable prostheses in patients who have suffered damage to the space of Retzius following pelvic surgery or obliteration of the transversalis fascia by mesh hernia repair. Since then, surgical techniques and tools for ectopic reservoir placement have gradually gained acceptance to minimize palpability, and the risk of visceral and vascular lesions for high risk patients has been all but eliminated. Lockout valves and high submuscular placement techniques are now recommended, and reports of vascular, bowel or bladder injuries are uncommonly rare. While surgeons continue their search for safer and more effective placement methods, new skills and instruments are constantly being introduced to make recommendations to minimize complications and provide safety and functionality. Additional studies and comparisons of techniques are needed to achieve a consensus of best practice for reservoir placement solutions.

Successful use of Transversalis fascia plane block for iliac crest bone harvesting in a Polytrauma patient - A case report.

Iliac crest bone grafting is very common associated procedure in various bone fixation surgery. We report here successful use of Transversalis fascia plane (TFP) block for iliac crest bone harvesting in a Polytrauma patient with difficult airway.

Comparative study of collagen and elastin content of abdominal wall fascia in inguinal hernia and non-hernia patients in an African population.

PURPOSE: Altered composition of collagen and elastin in abdominal fascia has been linked with the pathogenesis of hernias. This has not been studied amongst Africans who have hernia presentations which vary significantly from Caucasian cohorts. The aim of this study was to determine, and compare, the collagen and elastin contents of the transversalis fascia and rectus sheath of inguinal hernia patients with non-hernia controls. METHODS: Twenty-five patients with solitary, primary, uncomplicated inguinal hernia and twenty-five non-hernia controls were evaluated. Biopsies of the transversalis fascia and anterior rectus sheath were stained with Masson Trichrome and Verhöeff van-Gieson to isolate collagen and elastin respectively, which were quantified using the ImageJ/Fiji® image analysis software. RESULTS: Inguinal hernia patients were aged 19-85 years with a mean age of 45.2 years, mean body mass index (BMI) of 23.3 kg/m2 and mean duration of hernia of 42.5 months. Lateral hernias with no hernia defect or posterior wall defect [PL0] were the predominant clinical type. There were significantly lower collagen and higher elastin content in the transversalis fascia and rectus sheath of inguinal hernia patients [P < 0.001]. Regression analysis identified smoking and long duration of hernias as independent predictors of low collagen levels in this study CONCLUSION: Inguinal hernia patients in the study population demonstrated depleted collagen in the connective tissue of the inguinal canal. This might justify the routine use of prosthetic mesh for the reinforcement of the posterior wall during hernia repair.

[Anatomical revivification of the structure of the belt vessel].

On the base of the records in Huangdi Neijing (Yellow Emperor 's Inner Classic) and relevant ancient literature, the anatomical structure of the belt vessel was revivified. The belt vessel covers the kidneys and inlays in the 14th vertebrae on the lumbar region. It joints qijie (qi street) at the groin and connects with the thoroughfare vessel, the conception vessel and the governor vessel, as well as the muscle region of foot-yangming meridian. Correspondingly, the related anatomic structure includes renal fascia and transversalis fascia. The transversalis fascia is the main part of the belt vessel structure. The superior lumbar triangle is the vulnerable spot of abdominal wall structure and also coincident with the localization of "3 cun away from the spinal column bilaterally". It is the optimal selection when stimulating the belt vessel. In late generations, "governing all of meridians" has been supplemented as the function of the belt vessel. The diaphragm extends to the transversalis fascia and renal fascia through the inferior diaphragmatic fascia and it is also the only structure that connects with the twelve meridians and five zang organs. Hence, modern acupuncture and moxibustion has actually transferred the structural center of the belt vessel from the transversalis fascia to the diaphragm.

Posterior rectus canal: not a single anatomical entity & morphology - a laparoscopic study during TEP hernioplasty.

OBJECTIVES: Posterior rectus canal assumed immense importance with newer laparoscopic technique of total extra-peritoneal pre-peritoneal (TEPP/TEP) hernioplasty for inguinal hernia. However, scientific study of live surgical anatomy of posterior rectus canal is almost totally lacking in the English literature, and hence the present study was conducted. MATERIAL AND METHODS: 3-midline-port technique through posterior rectus sheath approach; Initial telescopic dissection under direct CO2 insufflation followed by instrument dissection. RESULTS: 68 TEPP hernioplasties were successful in 60 patients with mean age of 50.1 ± 17.2 years (range 18-80) and mean BMI of 22.6 ± 2.0 kg/m2 (range 19.5-31.2). Rectusial fascia was a definite anatomical entity, dividing traditional posterior rectus canal into two channels, namely, true retromuscular space and true posterior rectus canal (T-PRC). Rectusial fascia was variable, i.e., thick diaphanous (n= 47), thick membranous (n= 13), thin membranous (n= 3) and thin flimsy (n= 5). Posterior rectus sheath (PRS) was also variable, incomplete (n= 54) and complete (n= 14). Incomplete PRS showed seven variations in both extent and/or morphology. Complete PRS show five morphological variations. Transversalis fascia demonstrated three morphological variations, namely, single diaphanous (n= 41), single membranous (= 10) and thin flimsy (n= 3). TEPP hernioplasty was readily feasible through avascular true posterior rectus canal. CONCLUSION: Posterior rectus canal is divided by 'rectusial fascia' into two channels, namely, true retromuscular space and true posterior rectus canal, latter being proper avascular plane of dissection for TEPP hernioplasty. Rectusial fascia, posterior rectus sheath and transversalis fascia showed morphological variations. Timely recognition of variable real-time anatomy is recommended to perform adequate proper surgical dissection for seamless TEPP hernioplasty with ease, rapidity and safety.

Delayed Incisional Hernia Following Minimally Invasive Trans-Psoas Lumbar Spine Surgery: Report of a Rare Complication and Management.

BACKGROUND: Lateral lumbar interbody fusion (LLIF) has proved to be a safe tool in the armamentarium of spine surgeons for a variety of lumbar disorders. However, it has some complications related to specific approaches. Incisional hernia following abdominal surgery and anterior spinal surgery is commonly described; however, it is extremely rare following LLIF, with only 1 case reported in short postoperative period. In this report we present the first case of delayed presentation of true incisional hernia following a LLIF procedure and highlight its presentation, mechanism, possible preventive measures, and management. METHODS: We report a 57-year-old lady who underwent L3-4 LLIF. She presented with vague pain in a healed scar area that had no swelling until two years postsurgery, when she developed a painful swelling. On examination, it appeared to be a herniation of abdominal contents. RESULTS: She underwent a laparoscopic hernia repair surgery. The muscular layers were found to be intact with an attenuated transversalis fascia layer. The repair was reinforced by polypropylene mesh. There was no recurrence at the 6-month follow-up. CONCLUSIONS: Incisional hernia can occur following LLIF months to years following surgery and can have varied presentation. Tight external oblique closure should be performed because the transversalis fascia often cannot be repaired and the quality of a layered closure of the deep obliques is often disappointing. The treating surgeon should be aware of this complication and aggressively surveil for the warning signs, and patients should be counseled about this potential complication.

Paradigm shift regarding the transversalis fascia, preperitoneal space, and Retzius' space.

BACKGROUND: There has been confusion in the anatomical recognition when performing inguinal hernia operations in Japan. From now on, a paradigm shift from the concept of two-dimensional layer structure to the three-dimensional space recognition is necessary to promote an understanding of anatomy. ANATOMY AND EMBRYOLOGY: Along with the formation of the abdominal wall, the extraperitoneal space is formed by the transversalis fascia and preperitoneal space. The transversalis fascia is a somatic vascular fascia originating from an arteriovenous fascia. It is a dense areolar tissue layer at the outermost of the extraperitoneal space that runs under the diaphragm and widely lines the body wall muscle. The umbilical funiculus is taken into the abdominal wall and transformed into the preperitoneal space that is a local three-dimensional cavity enveloping preperitoneal fasciae composed of the renal fascia, vesicohypogastric fascia, and testiculoeferential fascia. The Retzius' space is an artificial cavity formed at the boundary between the transversalis fascia and preperitoneal space. In the underlay mesh repair, the mesh expands in the range spanning across the Retzius' space and preperitoneal space.

Anterior transversalis fascia approach versus preperitoneal space approach for inguinal hernia repair in residents in northern China: study protocol for a prospective, multicentre, randomised, controlled trial.

INTRODUCTION: Many surgical techniques have been used to repair abdominal wall defects in the inguinal region based on the anatomic characteristics of this region and can be categorised as 'tension' repair or 'tension-free' repair. Tension-free repair is the preferred technique for inguinal hernia repair. Tension-free repair of inguinal hernia can be performed through either the anterior transversalis fascia approach or the preperitoneal space approach. There are few large sample, randomised controlled trials investigating the curative effects of the anterior transversalis fascia approach versus the preperitoneal space approach for inguinal hernia repair in patients in northern China. METHODS AND ANALYSIS: This will be a prospective, large sample, multicentre, randomised, controlled trial. Registration date is 1 December 2016. Actual study start date is 6 February 2017. Estimated study completion date is June 2020. A cohort of over 720 patients with inguinal hernias will be recruited from nine institutions in Liaoning Province, China. Patient randomisation will be stratified by centre to undergo inguinal hernia repair via the anterior transversalis fascia approach or the preperitoneal approach. Primary and secondary outcome assessments will be performed at baseline (prior to surgery), predischarge and at postoperative 1 week, 1 month, 3 months, 1 year and 2 years. The primary outcome is the incidence of postoperative chronic inguinal pain. The secondary outcome is postoperative complications (including rates of wound infection, haematoma, seroma and hernia recurrence). ETHICS AND DISSEMINATION: This trial will be conducted in accordance with the Declaration of Helsinki and supervised by the institutional review board of the Fourth Affiliated Hospital of China Medical University (approval number 2015-027). All patients will receive information about the trial in verbal and written forms and will give informed consent before enrolment. The results will be published in peer-reviewed journals or disseminated through conference presentations. TRIAL REGISTRATION NUMBER: NCT02984917; preresults.

Understanding Retroperitoneal Anatomy for Lateral Approach Spine Surgery.

Lateral approach spine surgery provides effective interbody stabilization, and correction and indirect neural decompression with minimal-incision and less invasive surgery compared with conventional open anterior lumbar fusion. It may also avoid the trauma to paraspinal muscles or facet joints found with transforaminal lumbar interbody fusion and posterior lumbar interbody fusion. However, because lateral approach surgery is fundamentally retroperitoneal approach surgery, it carries potential risk to intra- and retroperitoneal structures, as seen in a conventional open anterior approach. There is an innovative lateral approach technique that reveals different anatomical views; however, it requires reconsideration of the traditional surgical anatomy in more detail than a traditional open anterior approach. The retroperitoneum is the compartmentalized space bounded anteriorly by the posterior parietal peritoneum and posteriorly by the transversalis fascia. The retroperitoneum is divided into three compartments by fascial planes: anterior and posterior pararenal spaces and the perirenal space. Lateral approach surgery requires mobilization of the peritoneum and its content and accurate exposure to the posterior pararenal space. The posterior pararenal space is confined anteriorly by the posterior renal fascia, anteromedially by the lateroconal fascia, and posteriorly by the transversalis fascia. The posterior renal fascia, the lateroconal fascia or the peritoneum should be detached from the transversalis fascia and the psoas fascia to allow exposure to the posterior pararenal space. The posterior pararenal space, however, does not allow a clear view and identification of these fasciae as this relationship is variable and the medial extent of the posterior pararenal space varies among patients. Correct anatomical recognition of the retroperitoneum is essential to success in lateral approach surgery. Spine surgeons must be aware that the retroperitoneal membrane and fascia is multilayered and more complex than is commonly understood. Preoperative abdominal images would facilitate more efficient surgical considerations of retroperitoneal membrane and fascia in lateral approach surgery.