Surgical Strategy for T2 Gallbladder Cancer: Nationwide Multicenter Survey in Korea

BACKGROUND: Although all guidelines suggest that T2 gallbladder (GB) cancer should be treated by extended cholecystectomy (ECx), high-level scientific evidence is lacking because there has been no randomized controlled trial on GB cancer. METHODS: A nationwide multicenter study between 2000 and 2009 from 14 university hospitals enrolled a total of 410 patients with T2 GB cancer. The clinicopathologic findings and long-term follow-up results were analyzed after consensus meeting of Korean Pancreas Surgery Club. RESULTS: The 5-year cumulative survival rate (5YSR) for the patients who underwent curative resection was 61.2%. ECx group showed significantly better 5YSR than simple cholecystectomy (SCx) group (65.4% vs. 54.0%, P = 0.016). For N0 patients, there was no significant difference in 5YSR between SCx and ECx groups (68.7% vs. 73.6%, P = 0.173). Systemic recurrence was more common than locoregional recurrence (78.5% vs. 21.5%). Elevation of cancer antigen 19-9 level preoperatively and lymph node (LN) metastasis were significantly poor prognostic factors in a multivariate analysis. CONCLUSION: ECx including wedge resection of GB bed should be recommended for T2 GB cancer. Because systemic recurrence was more common and recurrence occurred more frequently in patients with LN metastasis, postoperative adjuvant therapy should be considered especially for the patients with LN metastasis.

Determination of the Stress Factor Calculated from the Changes in the Measured Resting Energy Expenditure with Indirect Calorimetry in Patients Undergoing Pancreaticoduodenectomy

PURPOSE: To predict the energy expenditure using the stress factor representing the ratio of the metabolic variation between pre-operation and post-operation in a pancreaticoduodenectomy (PD). METHODS: This was a prospective study conducted on 17 patients (11 males and 6 females) who underwent PD at Chonbuk National University Hospital between March 2010 and October 2011. The rest energy expenditure was measured by indirect calorimetry 1 day before and 3 days after surgery. The height, weight, and fat free mass were also measured 1 day before surgery. RESULTS: The mean measured rest energy expenditure 1 day before PD (mREEpre) and 3 days after PD (mREEpost) were significantly different (16.8±2.6 vs. 18.8±3.5 kcal/kg/d, P=0.0076). The stress factor, representing the ratio of the metabolic changes between pre- and post-PD, was 1.12±0.17. The recommended energy requirement for PD patients is estimated to be 23∼24 kcal/ideal body weight/d [determined from the measured preoperative rest energy expenditure (16.8±2.6 kcal/kg/d)×activity factor (1.2∼1.3)×stress factor (1.12)]. CONCLUSION: PD patients maintained a hypermetabolic status and the applicable stress factor was 1.12.

Characterization of mesenchymal cells beneath cornification of the fetal epithelium and epidermis at the face: an immunohistochemical study using human fetal specimens / 대한해부학회지

Fetal development of the face involves a specific type of cornification in which keratinocytes provide a mass or plug to fill a cavity. The epithelial-mesenchymal interaction was likely to be different from that in the usual skin. We examined expression of intermediate filaments and other mesenchymal markers beneath cornification in the fetal face. Using sections from 5 mid-term human fetuses at 14–16 weeks, immunohistochemistry was conducted for cytokeratins (CK), vimentin, nestin, glial fibrilary acidic protein, desmin, CD34, CD68 and proliferating cell nuclear antigen (PCNA). Fetal zygomatic skin was composed of a thin stratum corneum and a stratum basale (CK5/6+, CK14+, and CK19+) and, as the intermediate layer, 2–3 layered large keratinocytes with nucleus. The basal layer was lined by mono-layered mesenchymal cells (CD34+ and nestin+). Some of basal cells were PCNA-positive. In the keratinocyte plug at the external ear and nose, most cell nuclei expressed PCNA, CK5/6, CK14, and CK19. Vimentin-positive mesenchymal cells migrated into the plug. The PCNA-positive nucleus as well as mesenchymal cell migration was not seen in the lip margin in spite of the thick keratinocyte layer. The lingual epithelium were characterized by the CK7-positive stratum corneum as well as the thick mesenchymal papilla. CD68-positive macrophages were absent in the epidermis/epithelium. Being different from usual cornification of the skin, loss of a mesenchymal monolayer as well as superficial migration of mesenchymal cells might connect with a specific differentiation of keratinocyte to provide a plug at the fetal nose and ear.

Predictive Factors of Malignant Potential in Gallbladder Polyps / 대한췌담도학회지

BACKGROUND/AIMS: Although the incidence of GB polyps is increasing with improved surveillance, the study of predictive factors of malignant potential has not been sufficient. The aim of this retrospective study is to investigate the predictive factors of malignant potential in GB polyps. METHODS: Among 3,159 patients with laparoscopic cholecystectomy in Chonbuk National University hospital January 2009 to December 2013, 437 patients confirmed GB polyps pathologically were enrolled. The patients were divided into two groups; one with benign GB polyp and another with GB adenoma and incidental GB cancer. RESULTS: Group I with benign GB polyp was seen in 359 patients. On the other hand, 53 patients with GB adenoma and 25 patients with GB cancer in gourp II were identified. The patients in group II had shown a significantly higher incidence of age older than 50 years (53/78, 67.9% vs. 163/359, 45.4%, p=0.001), size larger than 10mm (40/78, 51.3% vs. 37/359, 10.3%, p<0.001), and GB wall thickening (36/78, 46.2% vs. 77/359, 21.5%, p<0.001). The presence of GB stone had not shown significant differences between two groups (26/78, 33.3% vs. 96/359, 26.7%, p=0.378). CONCLUSIONS: Cholecystectomy should be considered for the patients with GB polyp with these predictive factors.

An anomalous portal vein crossing the lesser sac and ending at the upper part of ductus venosus / 대한해부학회지

In serial sagittal sections of a fetus on week 9 (crown-rump length, 36 mm), we incidentally found absence of the usual portal vein through the hepatoduodenal ligament. Instead, an anomalous portal vein originated behind the pancreatic body, crossed the lesser sac and merged with the upper part of the ductus venosus. During the course across the lesser sac, the vein provided a deep notch of the liver caudate lobe (Spiegel's lobe). The hepatoduodenal ligament contained the hepatic artery, the common bile duct and, at the right posterior margin of the ligament, and a branch of the anomalous portal vein which communicated with the usual right branch of the portal vein at the hepatic hilum. The umbilical portion of the portal vein took a usual morphology and received the umbilical vein and gave off the ductus venosus. Although it seemed not to be described yet, the present anomalous portal vein was likely to be a persistent left vitelline vein. The hepatoduodenal ligament was unlikely to include the left vitelline vein in contrast to the usual concept.

Usefulness of Artificial Jump Graft to Portal Vein Thrombosis in Deceased Donor Liver Transplantation

Severe portal vein thrombosis (PVT) is often considered a relative contraindication for living donor liver transplantation due to high associated risks and morbidity. Meanwhile, improvement in operative techniques, resulting in higher success rates has removed PVT from the list of contraindications in deceased donor liver transplantation (DDLT). In this report, we describe a surgical technique for DDLT using polytetrafluoroethylene graft from the inferior mesenteric vein for portal inflow in patient with portomesenteric thrombosis.

Distribution of CD10-positive epithelial and mesenchymal cells in human mid-term fetuses: a comparison with CD34 expression / 대한해부학회지

CD10, a marker of immature B lymphocytes, is expressed in the developing epithelium of mammary glands, hair follicles, and renal tubules of human fetuses. To assess mesenchymal and stromal expression of CD10, we performed immunohistochemical assays in whole body sections from eight fetuses of gestational ages 15-20 weeks. In addition to expression in urinary tract and intestinal epithelium, CD10 was strongly expressed at both gestational ages in fibrous tissues surrounding the airways from the larynx to lung alveoli, in the periosteum and ossification center, and in the glans of external genitalia. CD10 was not expressed, however, in other cavernous tissues. These findings suggest that mesenchymal, in addition to epithelial cells at specific sites, are likely to express CD10. The glomeruli, alveoli, and glans are all end products of budding or outgrowth processes in the epithelium or skin. However, in contrast to the CD34 marker of stromal stem cells, CD10 was not expressed in vascular progenitor cells and in differentiated vascular endothelium. The alternating pattern of CD10 and CD34 expression suggests that these factors play different roles in cellular differentiation and proliferation of the kidneys, airway and external genitalia.

A multicenter experience with generic mycophenolate mofetil conversion in stable liver transplant recipients

PURPOSE: Generic substitution of brand-name medications can lead to significant cost savings and is an accepted medical practice. This study evaluated clinical and safety outcomes among liver transplant recipients whose mycophenolate mofetil (MMF) was converted from the brand-name formulation (Cellcept) to a generic formulation (My-rept). METHODS: Clinical data from multiple centers were prospectively collected for determination of complications, safety, and quality of life after in 154 clinically stable, adult liver transplant recipients whose MMF was converted to a generic formulation between April 2010 and September 2012. This protocol was approved by Institutional Review Boards of all involved sites. RESULTS: In eight patients (5.19%), nine instances of drug-related complications occurred after medication conversion. Half of these complications were gastrointestinal disorders (n = 4), and most (7 of 9) were mild. No significant differences were noted in mean pre- and postconversion gastrointestinal symptoms via a rating system (8.9 vs. 10.4) or gastrointestinal quality-of-life index scores (125.6 vs. 123.1). More than 90% of patients reported a status of "about the same" when questioned about the brand-name and generic formulation using the Patient Overall Treatment Effect and Investigator Overall Treatment Effect measures. The incidence of serious adverse events was 5.8%. Acute rejection occurred in two patients, with no graft loss or death. CONCLUSION: Clinical experience as well as research data showed that generic MMF was comparable in efficacy to the brand-name drug. Given the lack of adverse events and the safety findings, conversion from brand-name MMF to generic MMF should be encouraged.

SPA0355 attenuates ischemia/reperfusion-induced liver injury in mice

Hepatic ischemia/reperfusion (I/R) injury leads to oxidative stress and acute inflammatory responses that cause liver damage and have a considerable impact on the postoperative outcome. Much research has been performed to develop possible protective techniques. We aimed to investigate the efficacy of SPA0355, a synthetic thiourea analog, in an animal model of hepatic I/R injury. Male C57BL/6 mice underwent normothermic partial liver ischemia for 45 min followed by varying periods of reperfusion. The animals were divided into three groups: sham operated, I/R and SPA0355 pretreated. Pretreatment with SPA0355 protected against hepatic I/R injury, as indicated by the decreased levels of serum aminotransferase and reduced parenchymal necrosis and apoptosis. Liver synthetic function was also restored by SPA0355 as reflected by the prolonged prothrombin time. To gain insight into the mechanism involved in this protection, we measured the activity of nuclear factor-kappaB (NF-kappaB), which revealed that SPA0355 suppressed the nuclear translocation and DNA binding of NF-kappaB subunits. Concomitantly, the expression of NF-kappaB target genes such as IL-1beta, IL-6, TNF-alpha and iNOS was significantly downregulated. Lastly, the liver antioxidant enzymes superoxide dismutase, catalase and glutathione were upregulated by SPA0355 treatment, which correlated with the reduction in serum malondialdehyde. Our results suggest that SPA0355 pretreatment prior to I/R injury could be an effective method to reduce liver damage.

Mesoesophagus and other fascial structures of the abdominal and lower thoracic esophagus: a histological study using human embryos and fetuses / 대한해부학회지

A term "mesoesophagus" has been often used by surgeons, but the morphology was not described well. To better understand the structures attaching the human abdominal and lower thoracic esophagus to the body wall, we examined serial or semiserial sections from 10 embryos and 9 fetuses. The esophagus was initially embedded in a large posterior mesenchymal tissue, which included the vertebral column and aorta. Below the tracheal bifurcation at the fifth week, the esophagus formed a mesentery-like structure, which we call the "mesoesophagus," that was sculpted by the enlarging lungs and pleural cavity. The pneumatoenteric recess of the pleuroperitoneal canal was observed in the lowest part of the mesoesophagus. At the seventh week, the mesoesophagus was divided into the upper long and lower short parts by the diaphragm. Near the esophageal hiatus, the pleural cavity provided 1 or 2 recesses in the upper side, while the fetal adrenal gland in the left side was attached to the lower side of the mesoesophagus. At the 10th and 18th week, the mesoesophagus remained along the lower thoracic esophagus, but the abdominal esophagus attached to the diaphragm instead of to the left adrenal. The mesoesophagus did not contain any blood vessels from the aorta and to the azygos vein. The posterior attachment of the abdominal esophagus seemed to develop to the major part of the phrenoesophageal membrane with modification from the increased mass of the left fetal adrenal. After postnatal degeneration of the fetal adrenal, the abdominal esophagus might again obtain a mesentery. Consequently, the mesoesophagus seemed to correspond to a small area containing the pulmonary ligament and aorta in adults.

Upper terminal of the inferior vena cava and development of the heart atriums: a study using human embryos / 대한해부학회지

In the embryonic heart, the primitive atrium is considered to receive the bilateral sinus horns including the upper terminal of the inferior vena cava (IVC). To reveal topographical anatomy of the embryonic venous pole of the heart, we examined horizontal serial paraffin sections of 15 human embryos with crown-rump length 9-31 mm, corresponding to a gestational age of 6-7 weeks or Carnegie stage 14-16. The IVC was often fixed to the developing right pulmonary vein by a mesentery-like fibrous tissue. Rather than the terminal portion of the future superior vena cava, the IVC contributed to form a right-sided atrial lumen at the stage. The sinus venosus or its left horn communicated with the IVC in earlier specimens, but in later specimens, the left atrium extended caudally to separate the sinus and IVC. In contrast, the right atrium consistently extended far caudally, even below the sinus horn, along the IVC. A small (or large) attachment between the left (or right) atrium and IVC in adult hearts seemed to be derived from the left (or right) sinus valve. This hypothesis did not contradict with the incorporation theory of the sinus valves into the atrial wall. Variations in topographical anatomy around the IVC, especially of the sinus valves, might not always depend on the stages but partly in individual differences.

Clinical feasibility and nutritional effects of early oral feeding after pancreaticoduodenectomy

BACKGROUNDS/AIMS: Pancreaticoduodenctomy (PD) is associated with high rates of postoperative morbidity and mortality. Although many studies have shown that early postoperative enteral nutrition improves postoperative outcomes, limited clinical information is available on postoperative early oral feeding (EOF) after PD. The aim of this study was to evaluate the clinical feasibility, safety, and nutritional effects of EOF after PD. METHODS: Clinical outcomes were investigated in 131 patients who underwent PD between 2003 and 2013, including 81 whose oral feeding was commenced within 48 hours (EOF group) and 50 whose oral feeding was commenced after resumption of bowel movements (traditional oral feeding [TOF] group). Postoperative complications, energy intake, and length of stay (LOS) were reviewed. RESULTS: Demographic factors were similar in the two groups. The EOF group had a significantly shorter LOS (25.9+/-8.5 days vs. 32.3+/-16.3 days; p=0.01) than the TOF group. The rates of anastomotic leak (1.2% vs. 16%, p=0.00) and reoperation (3.7% vs. 20%, p=0.01) were significantly lower in the EOF group. In the clinically acute phase from postoperative day 1 to day 5, the mean daily calorie intake (847.0 kcal vs. 745.6 kcal; p=0.04) and mean daily protein intake (42.2 g vs. 31.9 g; p=0.00) in the EOF group were significantly higher than that in the TOF group. CONCLUSIONS: Postoperative EOF is a clinically safe, feasible, and effective method of nutritional support after PD.

Spatial relationship between expression of cytokeratin-19 and that of connexin-43 in human fetal kidney / 대한해부학회지

Connexin-43, a major gap junction protein, and cytokeratin-19, one of the intermediate filament keratins, are known to be markers of well-differentiated epithelium. In this study, we investigated the expression of these markers in the head region, lungs, and abdominal organs of 10 human mid-term fetuses. The expression of connexin-43 was found to be restricted to the dura mater, kidney, and adrenal cortex. In the kidney, we found a clear site-dependent difference in the expression pattern of these markers: connexin-43 expression was observed in the tubules of the renal cortex whereas cytokeratin-19 was strongly expressed in the collecting ducts and renal pelvis. This difference remained unchanged throughout the fetal stages examined. Immunoreactivity was not observed for either of the markers in the intrarenal vessels, including the glomeruli, and mesangial cells. Connexin-43 expression seemed to be restricted to the metanephric vesicle-derived structures that differentiate in the urogenital ridge of the splanchnic mesoderm. The adrenal cortex also originates from the same para-aortic mesoderm. In contrast, in the urogenital organs, cytokeratin-19 seemed to be expressed in ducts derived from the urogenital sinus.

Clinicopathological characteristics and prognostic factors in combined hepatocellular carcinoma and cholangiocarcinoma

BACKGROUNDS/AIMS: Combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-CC) is an uncommon subtype of primary liver cancer that has rarely been reported in detail. This study was performed in order to evaluate the clinicopathological characteristics and prognostic factors of cHCC-CC in single center. METHODS: The clinicopathological features of patients diagnosed and operated with cHCC-CC at Chonbuk National Hospital between July 1998 and July 2007 were retrospectively studied by comparing them with patients with only hepatocellular carcinoma (HCC) who had undergone a hepatic resection during the same period. RESULTS: Ten out of 152 patients who had undergone a hepatic resection were diagnosed with cHCC-CC and thus included in this study (M : F=8 : 2, median age: 52+/-11.1 years). According to the parameters of the 7th American Joint Committee on Cancer T staging, there were 76 (50.0%), 44 (28.9%), 9 (5.9%), 18 (11.8%) and 5 (3.3%) patients with T stages 1, 2, 3a, 3b and 4, respectively. The overall survival period was longer in the HCC only group (68+/-40.4 months) than in the combined cHCC-CC group (23+/-40.1 months) (p<0.0001). The 5-year survival rate was 10% in the cHCC-CC group and 60% in the HCC group (p<0.0001). The disease free survival for patients with cHCC-HCC and HCC were 16+/-37.4 and 51+/-44.3 months, respectively (p<0.0001). Univariate analysis revealed that age, gender, transarterial chemoembolization (TACE), and T stage were statistically significant in terms of patient's overall survival. However, there were no significant clinicopathological factors identified by the multivariate analysis. CONCLUSIONS: Even after the hepatic resection in the HCC, the prognosis is poorer if the patient has cholangiocellular components compared to the usual HCC.

Multicystic Biliary Hamartoma of the Liver

Multicystic biliary hamartoma (MCBH) is a very rare hamartomatous cystic nodule of the liver, which has recently been described as a new entity of a hepatic nodular lesion. We report a unique case of MCBH with a review of the literatures. A hepatic multicystic mass of segment 3 was detected in a 52-year-old male by abdominal computed tomography, and resection of this lesion was performed. Macroscopic examination revealed a 2.7x2.0 cm nodular mass with a multicystic honeycomb cut surface. Histologically, this lesion consisted of multiple dilated cystic ducts lined by biliary type epithelial cells, periductal glands and connective tissue, which included small amounts of hepatic parenchyma and blood vessels. Recognition of this unusual lesion is essential to avoid confusion with other cystic tumors of the liver, and to learn more about its natural history and response to treatment.

Expression of carbonic anhydrase IX in human fetal joints, ligaments and tendons: a potential marker of mechanical stress in fetal development? / 대한해부학회지

Carbonic anhydrase type IX (CA9) is known to express in the fetal joint cartilage to maintain pH against hypoxia. Using paraffin-embedded histology of 10 human fetuses at 10-16 weeks of gestation with an aid of immunohistochemistry of the intermediate filaments, matrix components (collagen types I and II, aggrecan, versican, fibronectin, tenascin, and hyaluronan) and CA9, we observed all joints and most of the entheses in the body. At any stages examined, CA9-poisitive cells were seen in the intervertebral disk and all joint cartilages including those of the facet joint of the vertebral column, but the accumulation area was reduced in the larger specimens. Glial fibrillary acidic protein (GFAP), one of the intermediate filaments, expressed in a part of the CA9-positive cartilages. Developing elastic cartilages were positive both of CA9 and GFAP. Notably, parts of the tendon or ligament facing to the joint, such as the joint surface of the annular ligament of the radius, were also positive for CA9. A distribution of each matrix components examined was not same as CA9. The bone-tendon and bone-ligament interface expressed CA9, but the duration at a site was limited to 3-4 weeks because the positive site was changed between stages. Thus, in the fetal entheses, CA9 expression displayed highly stage-dependent and site-dependent manners. CA9 in the fetal entheses seemed to play an additional role, but it was most likely to be useful as an excellent marker of mechanical stress at the start of enthesis development.

Analyze the Patency Rates according to Risk Factors and Comorbidities in Patients with Chronic Arterial Occlusive Disease in Lower Extremity / 대한혈관외과학회지

PURPOSE: The aim of this study is to analyze the patency rates according to the risk factors and comorbidities in patients treated with endovascular treatments or arterial bypass surgery due to chronic arterial occlusive disease in the lower extremity. METHODS: Two hundred fifty-seven patients were treated for chronic arterial occlusive disease in lower extremity from January 2000 to December 2010 at Chonbuk National University Hospital; of the 257 patients, we retrospectively reviewed medical records of 142 patients who could be followed-up. We analyzed the patency rates according to the Trans-Atlantic Inter-Society Consensus (TASC) II classification, risk factors and comorbidities. RESULTS: One year, three year, and five year patency rates according to TASC classification had no statistical significance (P=0.301), and those risk factors and comorbidities associated with each other also had no statistical significance. However, the patency rates according to the number of risk factors and comorbidities demonstrated statistical significance (P=0.004), respectively. In addition, when sum of the total number was above 6, the patency rates were the poorest with statistical significance (P<0.001). Also, these analyses had statistical significance in the groups regarding TASC C, D (P<0.001), aorto-iliac lesions (P<0.001) and femoro-popliteal lesions (P<0.001). CONCLUSION: Analysis of risk factors and comorbidities in patients with chronic arterial occlusive disease in the lower extremity can be useful in predicting the patency rates prior to endovascular treatments or arterial bypass surgeries.

Dense distribution of macrophages in flexor aspects of the hand and foot of mid-term human fetuses / 대한해부학회지

In the developing human musculoskeletal system, cell death with macrophage accumulation occurs in the thigh muscle and interdigital area. To comprehensively clarify the distribution of macrophages, we immunohistochemically examined 16 pairs of upper and lower extremities without the hip joint (left and right sides) obtained from 8 human fetuses at approximately 10-15 weeks of gestation. Rather than in muscles, CD68-positive macrophages were densely distributed in loose connective tissues of the flexor aspects of the extremities, especially in the wrist, hand and foot. In contrast, no or fewer macrophages were evident in the shoulder and the extensor aspects of the extremities. The macrophages were not concentrated at the enthesis of the tendon and ligament, but tended to be arranged along other connective tissue fibers. Deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling revealed apoptosis in the hand lumbricalis muscles, but not in the area of macrophage accumulation. Likewise, podoplanin-positive lymphatic vessels were not localized to areas of macrophage accumulation. Re-organization of the connective tissue along and around the flexor tendons of the hand and foot, such as development of the bursa or tendon sheath at 10-15 weeks, might require the phagocytotic function of macrophages, although details of the mechanism remain unknown.

Surgical outcomes and prognostic factors influencing long-term survival in patients with gallbladder cancer

BACKGROUNDS/AIMS: The aim of this study is to analyze surgical outcomes and prognostic factors affecting survival after surgical resection in patients with gallbladder cancer. METHODS: We retrospectively reviewed 86 patients treated surgically for gallbladder cancer from January 2000 to December 2009 at Chonbuk National University Hospital. Clinicopathologic factors, surgical treatment and outcome data were analyzed. RESULTS: Among the 86 patients (44 male, 42 female) with gallbladder cancer, the mean age was 62.9 years (range: 32-80) and the median survival was 42.4+/-3.5 month. The overall cumulative survival rates of 86 patients were for 1 year, 83.7%; 3 year, 67.4%; 5 year survival, 61.7%. Univariate analysis revealed that preoperative serum alanine aminotransferase, alkaline phosphatase, total bilirubin, carcinoembryonic antigen (CEA), T staging, N staging were statistically significantly associated with survival. CEA (p=0.004) and T staging (p=0.005) were associated with survival in multivariate analysis. Two-year survival rates were analyzed according to the methods of surgical resection, with simple cholecystectomy showing 100%, whereas extended cholecystectomy showed about 83% in T1b. We could not find out any adverse effect of the simple cholecystectomy for survival. CONCLUSIONS: CEA and T stage are independent significant prognostic factor associated with patient survival in our study. Simple cholecystectomy can be regarded as curative resection in stage T1b. Longer observation periods and more cases will be needed to confirm these conclusions.

Anococcygeal Raphe Revisited: A Histological Study Using Mid-Term Human Fetuses and Elderly Cadavers

PURPOSE: We recently demonstrated the morphology of the anococcygeal ligament. As the anococcygeal ligament and raphe are often confused, the concept of the anococcygeal raphe needs to be re-examined from the perspective of fetal development, as well as in terms of adult morphology. MATERIALS AND METHODS: We examined the horizontal sections of 15 fetuses as well as adult histology. From cadavers, we obtained an almost cubic tissue mass containing the dorsal wall of the anorectum, the coccyx and the covering skin. Most sections were stained with hematoxylin and eosin or Masson-trichrome solution. RESULTS: The adult ligament contained both smooth and striated muscle fibers. A similar band-like structure was seen in fetuses, containing: 1) smooth muscle fibers originating from the longitudinal muscle coat of the anal canal and 2) striated muscle fibers from the external anal sphincter (EAS). However, in fetuses, the levator ani muscle did not attach to either the band or the coccyx. Along and around the anococcygeal ligament, we did not find any aponeurotic tissue with transversely oriented fibers connecting bilateral levator ani slings. Instead, in adults, a fibrous tissue mass was located at a gap between bilateral levator ani slings; this site corresponded to the dorsal side of the ligament and the EAS in the immediately deep side of the natal skin cleft. CONCLUSION: We hypothesize that a classically described raphe corresponds to the specific subcutaneous tissue on the superficial or dorsal side of the anococcygeal ligament.