Lateroconal Fascia Research Articles

The usefulness of preoperative CT in colon cancer staging: impact of radiologists' experience.

To assess the agreement between radiologists in the detection of specific features related to T- and N-stage and evaluate accuracy in colon cancer staging. Patients who underwent contrast-enhanced computed tomography (CECT) before surgery were enrolled and evaluated by three radiologists with different experience. Pathological data were used as the reference standard. Tumor location, presence of tumor bulging, fat stranding, lateroconal fascia invasion, enlarged vessels, axial short diameter of the biggest node, shape, enhancement pattern, intranodal necrosis, and cluster were collected. Reliability analysis was performed with κ statistics and intraclass correlation coefficients (ICCs). Logistic regressions were used to determine independent predictors associated with staging. Seventy five patients were evaluated. The reliability analysis was moderateto substantial for tumor location (κ = 0.853), T staging (κ = 0.531), tumor bulging (κ = 0.478), fat stranding (κ = 0.490), lateroconal fascia invasion (κ = 0.436), enlarged vessels (κ = 0.401), the axial short diameter of the biggest node (ICC = 0.732), shape (κ = 0.484), enhancement pattern (κ = 0.431), intranodal necrosis (κ = 0.606), and cluster (κ = 0.358). For all readers, sensitivity was higher for T3 lesions (60-69%) and specificity was higher for T2 and T4 lesions (84.5-90.0% and 82.4-85.1%). The diagnostic accuracy was acceptable for all lesions and among all readers (50.7-92.1%). The lateroconal fascia invasion and enlarged vessels resulted as independent predictor factors (OR = 3.292 and OR = 2.651) for T staging, while nodes' cluster and dimension as independent predictor factors of N staging [OR = 3.798 and OR = 1.083]. Reader's experience is one of the most important factors associated with the correct classification of colon cancer. Moreover, CECT can help depict radiological features independently associated with the T and N stages.

Gastroinstestinal Fistula in Acute Necrotising Pancreatitis with Septicaemia: A Case Report

Acute Pancreatitis (AP) is an inflammatory condition with cumbersome side effects. Gastropancreatic (GI) fistula is a rare complication seen in cases with infected pancreatic or peripancreatic necrosis. GI fistulas can result in severe haemorrhage and septicemia. Hereby, the authors present a case of 36-year-old male with a chief complaint of abdominal pain associated with abdominal distension and non bilious vomiting after binge consumption of alcohol for the past 10 days. Computed Tomography (CT) scan showed the presence of free gas in the abdomen. Contrast-Enhanced CT (CECT) imaging revealed diffuse enlargement affecting the head, uncinate process, body, and tail of the pancreas. There were also a few necrotic peripancreatic fluid collections with extensive peripancreatic fat stranding. Based on these findings, the diagnosis of acute necrotising pancreatitis was suggested. Despite treatment with antibiotics and necrosectomy with drainage of the abscess collection, the patient showed no improvement. A repeat CECT examination was performed due to the deterioration of the patient’s clinical condition, which showed a complete non enhancing pancreas. Additionally, a large defect measuring approximately 16 mm was observed in the posteroinferior wall of the stomach at the middle third of the body, with extravasation of contrast material into the pancreatic collection, suggestive of fistula formation. Subsequently, the patient underwent pancreatic necrosectomy with closure of the gastric perforation using feeding jejunostomy. A follow-up CT examination was performed four days later due to the deteriorating status of the patient, as well as new onset haematemesis and bloody discharge from the surgical drain. The CT scan revealed a few peripancreatic soft tissue infiltrates adjacent to the pancreatic head. Persistent collections were noted along the anterolateral surface of the right psoas, extending to the adjoining right anterior pararenal space and the left anterolateral abdominal wall in the left hypochondriac region. Thickening of the bilateral lateroconal fascia and anterior and posterior renal fascia was observed, likely due to inflammation. Following this, the patient underwent another surgery, and percutaneous drainage was performed with antibiotic coverage. The patient showed a significant reduction in the collection and improved clinical condition after 10 days. Imaging plays a crucial role in diagnosing such complications, enabling early detection and reducing mortality in these patients.

Lateroconal fascia suspension facilitates retroperitoneal partial nephrectomy.

BackgroundAs the development of various imaging techniques, the incidental detection of renal masses is increasing. Laparoscopic partial nephrectomy (LPN) is the current standard of treatment for renal carcinoma. Though the retroperitoneal laparoscopic partial nephrectomy (RLPN) become the prior choice, the edge of lateroconal fascia blocks the sight and make operation more challenging.MethodsBetween October 2018 and December 2020, the clinical data of 28 cases diagnosed with renal cell carcinoma (RCC) in our hospital was collected and analyzed retrospectively. All patients underwent RLPN and for management of curtain effect, we performed lateroconal fascia suspension (LFS) procedure in all cases with prepared Hem-o-lock clip which bound with 2-0 suture.ResultsRLPN for renal tumor was successfully performed in all cases with no conversions to open surgery and other interruptions. In all cases, the free edge of lateroconal fascia and peritoneum partially blocked the sight of surgeon. We managed the curtain effect successfully and got a satisfying field of view for subsequent surgical procedure. The median operation time was 142 [interquartile range (IQR), 110–164] min, median estimated blood loss was 93 (IQR, 50–100) mL. Median warm ischemia time was 29 (IQR, 22–30) min.ConclusionsLFS is useful for management of curtain effect. It is a simple, economical and less invasive technique and we can get better efficiency with little consumption.

481 - Significant impact of three-dimensional volumetry of perinephric fat on the console time during robot-assisted partial nephrectomy

To assess the impact of volumetry of perinephric fat (PNF) on the perioperative outcomes of robot-assisted partial nephrectomy (RAPN). Between 2016 and 2019, a single surgeon performed RAPN for 128 patients with clinical T1a-b renal tumors at our institution, and the 70 most recent patients were included in this study to minimize the effects of surgical experience. PNF was defined as a fatty area around the kidney within the anatomical structures, including the lateroconal fascia, fusion fascia, psoas muscle, lumbar quadrate muscle and diaphragm, and its volume was calculated based on reconstructed three-dimensional computed tomography images using the SYNAPSE VINCENT system. In this series, the trifecta and MIC (margin, ischemia and complications) score system outcomes were achieved in 69 (98.6%) and 64 patients (91.4%), respectively. The median PNF volume in the 70 patients was 166.05 cm3, which was significantly correlated with both the body mass index (BMI) and Mayo adhesive probability (MAP) score (correlation coefficient = 0.68 and 0.74, respectively). There was no significant difference in the R.E.N.A.L. nephrometry score, PNF volume or console time during RAPN among 5 groups consisting of 14 consecutive patients. Of several factors examined, the console time was significantly affected by the sex, MAP score and PNF volume, and only the PNF volume was independently associated with the console time. Even if performed by an experienced robotic surgeon beyond the initial learning curve, the PNF volume may influence the console time during RAPN.

Significant impact of three-dimensional volumetry of perinephric fat on the console time during robot-assisted partial nephrectomy

BackgroundTo assess the impact of volumetry of perinephric fat (PNF) on the perioperative outcomes of robot-assisted partial nephrectomy (RAPN).MethodsBetween 2016 and 2019, a single surgeon performed RAPN for 128 patients with clinical T1a-b renal tumors at our institution, and the 70 most recent patients were included in this study to minimize the effects of surgical experience. PNF was defined as a fatty area around the kidney within the anatomical structures, including the lateroconal fascia, fusion fascia, psoas muscle, lumbar quadrate muscle and diaphragm, and its volume was calculated based on reconstructed three-dimensional computed tomography images using the SYNAPSE VINCENT system.ResultsIn this series, the trifecta and MIC (margin, ischemia and complications) score system outcomes were achieved in 69 (98.6%) and 64 patients (91.4%), respectively. The median PNF volume in the 70 patients was 166.05 cm3, which was significantly correlated with both the body mass index (BMI) and Mayo adhesive probability (MAP) score (correlation coefficient = 0.68 and 0.74, respectively). There was no significant difference in the R.E.N.A.L. nephrometry score, PNF volume or console time during RAPN among 5 groups consisting of 14 consecutive patients. Of several factors examined, the console time was significantly affected by the sex, MAP score and PNF volume, and only the PNF volume was independently associated with the console time.ConclusionEven if performed by an experienced robotic surgeon beyond the initial learning curve, the PNF volume may influence the console time during RAPN.

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.

Lateroconal fascia suspension for management of peritoneal tear and "curtain" effect during retroperitoneal laparoscopic operations.

To describe the method of lateroconal fascia suspension for the management of peritoneal tear and curtain effect during retroperitoneal laparoscopic operations. Between May 2013 and October 2014, we performed lateroconal fascia suspension in 30 cases of retroperitoneal laparoscopic operations. Peritoneal tear occurred and retroperitoneal space collapsed in 18 cases of them during the operation, and free edge of the lateroconal fascia caused curtain effect and sheltered the field of view in another 12 cases after the lateroconal fascia was incised longitudinally. The curtain effect of lateroconal fascia was eliminated successfully, and the sheltered field of view got normal in all the 12 cases. The collapsed retroperitoneal space due to peritoneal tear got enlarged effectively and was sufficient for the following operations in 15 patients of the overall 18 cases, while the collapsed retroperitoneal space did not get enlarged significantly in the other three cases. After the insertion of an extra 5-mm trocar into peritoneal space, the collapsed retroperitoneal space got enlarged eventually. Finally, retroperitoneal laparoscopic operations were continued and completed successfully in all these 30 patients. It took 4min to complete the suspension procedure, and no related complications occurred during the whole suspension process. Lateroconal fascia suspension method could manage most peritoneal tears and curtain effect effectively during retroperitoneal laparoscopic operations.

Preliminary embryological study of the radiological concept of retroperitoneal interfascial planes: what are the interfascial planes?

Recently, the radiological concept of retroperitoneal interfascial planes has been widely accepted to explain the extension of retroperitoneal pathologies. This study aimed to explore embryologically based corroborative evidence, which remains to be elucidated, for this concept. Using serial or semi-serial transverse sections from 29 human fetuses at the 5th-25th week of fetal age, we microscopically observed the development of the retroperitoneal fasciae and other structures in the retroperitoneal connective tissue. A hypothesis for the formation of the interfascial planes was generated from the developmental study and analysis of retroperitoneal fasciae in computed tomography images from 224 patients. Whereas the loose connective tissue was uniformly distributed in the retroperitoneum by the 9th week, the primitive renal and transversalis fasciae appeared at the 10th-12th week, as previous research has noted. By the 23rd week, the renal fascia, transversalis fascia, and primitive adipose tissue of the flank pad emerged. In addition, the primitive lateroconal fascia, which runs parallel to and close to the posterior renal fascia, emerged between the renal fascia and the adipose tissue of the flank pad. Conversely, pre-existing loose connective tissue was sandwiched between the opposing fasciae and was compressed and narrowed by the developing organs and fatty tissues. Through this developmental study, we provided the hypothesis that the compressed loose connective tissue and both opposed fasciae compose the interfascial planes. Analysis of the thickened retroperitoneal fasciae in computed tomography images supported this hypothesis. Further developmental or histological studies are required to verify our hypothesis.

Retroperitoneoscopic nephrectomy for treatment of a case of left single ectopic ureter accompanied by dysplastic kidney.

We report the case of a 7-year-old girl with a single ectopic ureter who was treated with retroperitoneoscopic nephrectomy for a chief complaint of urinary incontinence. Preoperative CT showed a contrasted dysplastic kidney of 1cm in the renal fossa and a left ureteral opening into the vagina. Retroperitoneoscopic left nephrectomy was conducted with opening of the lateroconal fascia to enable identification of the dysplastic kidney. No intraoperative complications were encountered. Urinary incontinence improved immediately after surgery. This case shows that a retroperitoneal approach can be used in nephrectomy if the position of the kidney can be determined preoperatively.

Subcutaneous emphysema of the penis and scrotum mimicking gas gangrene: a rare complication of ERCP

A 61-year-old man underwent ERCP and sphincterotomy with removal of two 1.5-cm stones from the common bile duct. Twelve hours after the procedure, he reported that his penis and scrotum were painful and swollen. He was afebrile and had no abdominal pain, distention, vomiting, or urinary symptoms. His abdomen was soft and nontender. The penis and scrotum were tender and diffusely swollen with crepitus typical of emphysema; the overlying skin appeared normal. An abdominal film showed air outlining the right psoas shadow and right kidney. CT scan of the abdomen and pelvis showed multiple air loculi around the second part of duodenum, with extensive involvement of right perinephric space and retroperitoneum (A). Air was seen to track from the retroperitoneum along the left lateroconal fascia into the left anterior parietal wall and from there into the scrotal sac (B,C). There was no free fluid in the peritoneal cavity and no leakage of contrast. With the temporal relationship of the clinical features and ERCP, a diagnosis of retroperitoneal duodenal perforation was made. Because there were no clinical signs of peritonitis, the patient was managed conservatively and did well.

Development of the Human Retroperitoneal Fasciae

Introduction: Although the renal fascia (RF), ureteral sheath, lateroconal fascia (LF) and hypogastric nerve are critical landmarks for retroperitoneal surgery, their laminar relationships require clarification. Materials and Methods: Horizontal sections (hematoxylin-eosin staining) of human fetuses at two different developmental stages [9–12 (3 fetuses, crown-rump length, CRL 40–65 mm) and 20–25 weeks of gestation (9 fetuses, CRL 152–220 mm)] were compared. Results: In the early-stage group, the pararenal space had already formed between the posterior RF and the transversalis fascia (TF). The anterior RF extended along the peritoneum and often fused with the latter. In the late-stage group, the posterior RF extended inferomedially toward the anterior aspect of the aorta and inferior vena cava. However, at the level of the renal hilus, the posterior RF was connected with vascular sheaths of the great vessels. The LF was seen developing as a fasciculation of the multilaminar structure in the pararenal space. However, on the posterolateral side of the colon after retroperitoneal fixation, the fusion fascia of the peritoneum could also be identified as LF. Conclusions: A common sheath for ureters and hypogastric nerves appeared to be likely on the inferior side of the kidney. The LF did not appear to be a primary structure such as the RF, but a result of secondary mechanical stress due to fatty tissue developing earlier along the TF than in the perirenal space. However, the suggested similarity between LF and fusion fascia in the plane occupied was a likely cause for misinterpreting the laminar configurations during surgery.

A retrospective study of CT findings in cases undergoing appendectomy at a single hospital

The purpose of this study was to determine which clinical information or computed tomography (CT) features can distinguish perforated from nonperforated appendicitis. We collected data from 102 patients (62 men, 40 women; mean age, 49.6 years; age range, 16-85 years) who presented to the emergency department with acute abdominal pain or suspicion of acute appendicitis and underwent appendectomy. In the clinical information, there was no significant factor to predict appendiceal perforation. As for CT features, significant imaging factors for predicting appendiceal perforation included abscess, phlegmon, and thickening of lateroconal fascia. The treatment strategy of acute appendicitis varies according to the integrity of the appendiceal wall. Besides clinical findings, CT features can distinguish perforated from nonperforated appendicitis, facilitating proper decision making in ER.

An Extreme Case of Retrorenal Colon

An Extreme Case of Retrorenal Colon An 84-year-old woman with a remote history of cholecystectomy was referred for investigation of intermittent right lower quadrant fullness and discomfort. Abdominal CT performed with the patient supine with positive oral and IV contrast material revealed extreme posterior and retrorenal positioning of the ascending and descending colon, wrapping around the lower pole of the kidneys and extending almost to the posterolateral border of the psoas muscles (Fig. 1). Retrorenal positioning of the colon, as determined by a line drawn coronally through the posterior margin of the kidney, has been reported variably in 1–14% of the population [1, 2]. Normally, the ascending and descending colon lie anterior to the kidneys in the anterior pararenal space, which is bordered anteriorly by the posterior parietal peritoneum, posteriorly by the anterior renal (Gerota’s) fascia, and posterolaterally by the lateroconal fascia (formed by the fusion of the anterior and posterior renal fascia at their lateral borders). Two theories have been proposed for the normal variant of the retrorenal colon. The first theory is that the more lateral and posterior colonic positioning is a result of a smaller amount of perinephric fat [3]. The second is that the absence of the lateroconal fascia, or its formation more posteromedially, may allow the colon to extend around the posterior margin of the perirenal space [1]. The retrorenal position of the colon places the colon at risk for iatrogenic trauma during percutaneous procedures directed at the kidneys such as biopsy, percutaneous nephrostomy, and nephrolithotomy. The frequency of retrorenal colon was found to be five times higher when patients were positioned prone (the favored position for percutaneous procedures) rather than supine [4]. It has been suggested that the prone positioning results in a more gas-distended colon, which might more easily displace the renal fascia and possibly even dissect between the laminae of the posterior renal fascia. Chan R, Li DKB Ryan Chan University of Ottawa Ottawa, ON, Canada

Ascending Retrocecal Appendicitis

To describe the clinical presentation and computed tomographic (CT) features of ascending retrocecal appendicitis. During the past 8 years, 1670 patients with surgically proven appendicitis were identified by a retrospective investigation. Thirty-three patients who underwent contrast-enhanced abdominal CT before surgery and had ascending retrocecal appendicitis at surgery were included in the patient cohort. The clinical and CT findings of these 33 patients were analyzed. Patients presented with right lower abdominal pain (49%, 16/33), right flank pain (24%, 8/33), right upper abdominal pain (18%, 6/33), and periumbilical pain (15%, 5/33). Inflamed ascending retrocecal appendices were visualized completely in 70% (23/33), partially in 21% (7 of 33), and not detected in the remaining 9% (3/33). Periappendiceal inflammatory changes were most commonly observed in the retrocolic space in 88% (29/33), followed by paracolic gutter (30%, 10/33), pararenal space (27%, 9/33), mesentery (24%, 8/33), perirenal space (18%, 6/33), and subhepatic space (3%, 1/33). Inflammatory thickening of Gerota fascia (70%, 23/33) and the lateroconal fascia (64%, 21/33) was observed as well. Perforation of the appendix with the formation of an abscess was present in 49% (16/33). The abscesses were most commonly located in the retrocolic space (88%, 14/16). Diffuse wall thickenings of the cecum (67%, 22/33) and the ascending colon (64%, 21/33) were often observed also. Appendicoliths were found in 33% (11/33). More than half of patients with ascending retrocecal appendicitis presented with atypical clinical presentation. At CT, ascending retrocecal appendicitis was associated with a high incidence of retroperitoneal inflammatory changes and appendiceal perforation.

100-MINUTE RETROPERITONEOSCOPIC RADICAL NEPHRECTOMY: A NEW RETROPERITONEAL APPROACH WITH A HAND ASSISTED METHOD

A new approach for retroperitoneoscopic radical nephrectomy is introduced. The point of our surgical method is the application of a combination of hand assistance and pure laparoscopic procedures with appropriate surgical steps via the retroperitoneal approach. In our early series we had good surgical results and we completed radical nephrectomy in about 100 minutes using this procedure. A total of 20 consecutive patients with renal cell carcinoma (cT1-2) who were operated on with this surgical method were analyzed. Surgical procedures occurred in 5 steps. In step 1 the retroperitoneal space was created manually from a pararectal incision at the umbilicus level. In step 2 the lateroconal fascia was incised and the renal hilar area was exposed with hand assistance. In step 3 hilar dissection was performed by pure laparoscopic procedure with another surgical instrument inserted from the hand device. Step 4 involved the application of hand assistance again for the quick mobilization of the kidney and adrenal gland. In step 5 the intact surgical specimen was retrieved from the hand device. Mean operative time and estimated blood loss were 103 +/- 21 minutes (range 70 to 145) and 49 +/- 85 ml (range 5 to 360), respectively. Mean days to oral intake and ambulation were 1.0 and 1.1, respectively. Operative times of the steps of hilar dissection and mobilization of the kidney and adrenal were shorter than in other series performed by standard retroperitoneoscopic radical nephrectomy. Major complications were not experienced. At this point, no metastasis has been experienced. Our surgical method may have the benefits of the retroperitoneal approach and hand assistance. The retroperitoneoscopic hand assisted method may be another important option in the 3 major approaches for laparoscopic radical nephrectomy, although longer-term followup is clearly required.

Spiral CT features and anatomic basis of posterior pararenal space involvement in acute pancreatitis

Objective To evaluate spiral CT features and anatomic basis of the posterior pararenal space (PPS) involvement in acute pancreatitis (AP). Methods CT images of 87 cases with AP were retrospectively studied with focus on spiral CT features, incidence of the PPS involvement, and its correlations with the posterior renal fascia or lateroconal fascia. Results Our study showed that the incidence of the PPS involvement was 47%(41/87), with Grade A 53%(46/87), Grade B 24%(21/87), and Grade C 23%(20/87), and Grade 0 53%(46/87), Grade Ⅰ 22%(19/87), and Grade Ⅱ 25%(22/87), respectively. The pancreatitis fluid collection in the PPS was continuous with that in the anterior pararenal space or with the fluid between the two laminae of the posterior renal fascia. In 3 follow-up cases, pseudocysts in the PPS were continuous with that in anterior pararenal space below the cone of renal fascia. Conclusion Spiral CT features of the PPS involvement varies from mild inflammatory changes to fluid collection or phlegmonous mass. Fluid within anterior pararenal space in AP flows into the PPS by three routes.

A case of Fitz-Hugh-Curtis syndrome: Thickening of the lateroconal fascia and posterior renal fascia.

We encountered a case of Fitz-Hugh-Curtis syndrome. Ultrasonography and computed tomography revealed a thickening of the lateroconal fascia and posterior renal fascia. These fasciae might be sensitive, although not specific, markers for this entity.

Endoscopic retroperitoneal adrenalectomy

Background: Open adrenalectomy requires a large incision of the abdominal wall or lumbar region which is associated with considerable morbidity. The endoscopic approach to adrenal surgery has the potential to reduce patient discomfort. Methods: The retroperitoneal space is created by balloon dissection with the patient in lateral decubitus position. Incision of the lateroconal fascia and dissection of the upper renal pole allow access to the adrenal gland and its removal. All adrenal pathology less than 6 cm in diameter is suitable for the endoscopic retroperitoneal approach. Results: Endoscopic retroperitoneal adrenalectomy has proven safe and effective in adrenal pathology except for adrenal tumors greater than 6 cm in diameter or for patients who have had earlier retroperitoneal surgery on the affected side. Conclusions: Endoscopic retroperitoneal adrenalectomy appears preferable because the adrenal tumor can be approached in its proper anatomical plane. Therefore, dissection or retraction of surrounding organs is unnecessary which renders the adrenalectomy more facile.

Uncomplicated acute diverticulitis of the cecum and ascending colon: sonographic findings in 18 patients.

To determine the sonographic features of uncomplicated acute diverticulitis of the cecum and ascending colon, the sonographic findings in 534 patients who presented with right lower quadrant pain were reviewed. Of these, 18 patients had uncomplicated acute diverticulitis of the cecum and ascending colon. The diagnosis was confirmed by surgery (one patient), clinical course (17 patients), CT (eight patients), or contrast enema (11 patients). On sonography, a round or oval focus of varying echogenicity, which protruded from a segmentally thickened colonic wall and was surrounded by a hyperechoic area, was seen in all 18 patients. These were hypoechoic foci (12 patients), hypoechoic foci with internal strong echoes (three patients), and echogenic shadowing foci with surrounding hypoechoic bands (three patients). Extraluminal gas (one patient) and thickening of lateroconal fascia (six patients) were seen also. Findings of enlarged appendix, frank abscess, and ascites were absent. All patients, including the one who had laparotomy, were successfully treated medically for diverticulitis. Of 515 patients without diverticulitis, in only one patient with acute appendicitis did sonography show a hypoechoic protruding focus. Our experience indicates that the major sonographic finding in patients with uncomplicated acute diverticulitis of the right colon is a hypoechoic round or oval focus protruding from a segmentally thickened colonic wall.

The anatomical basis for retrorenal extensions of pancreatic effusions: the role of the renal fasciae

Retrorenal extension of pancreatic inflammatory processes are considered to involve invasion of the posterior pararenal space. Analysis of computed tomographic (CT) images demonstrates preservation of posterior pararenal fat in most patients, implicating some other mechanism. We have examined the anatomical basis for these retrorenal extensions in static and functional studies of 12 cadavers using CT imaging, dissection and histological techniques. We observed that the posterior renal fascia was thicker than the anterior, that it could be easily separated into two layers by manual dissection and injections of liquid latex, that the inner (anterior) layer of the posterior fascia was continuous with the anterior fascia and the outer layer continuous with the lateroconal fascia. The point at which the two layers of the posterior fascia separated laterally and the medial extent of the posterior fascia varied considerably in CT scans of 100 patients. These data are interpreted to mean that pancreatic effusions extend posterior to the kidney by separating the two layers of the posterior renal fascia.