Electrocautery causes more ischemic peritoneal tissue damage than ultrasonic dissection

BACKGROUND

Minimizing peritoneal tissue injury during abdominal surgery has the benefit of reducing postoperative inflammatory response, pain, and adhesion formation. Ultrasonic dissection seems to reduce tissue damage. This study aimed to compare electrocautery and ultrasonic dissection in terms of peritoneal tissue ischemia measured by microdialysis.

METHODS

In this study, 18 Wistar rats underwent a median laparotomy and had a peritoneal microdialysis catheter implanted in the left lateral sidewall. The animals were randomly assigned to receive two standard peritoneal incisions parallel to the catheter by either ultrasonic dissection or electrocautery. After the operation, samples of microdialysis dialysate were taken every 2 h until 72 h postoperatively for measurements of pyruvate, lactate, glucose, and glycerol, and ratios were calculated.

RESULTS

The mean lactate-pyruvate ratio (LPR), lactate-glucose ratio (LGR), and glycerol concentration were significantly higher in the electrocautery group than in the ultrasonic dissection group until respectively 34, 48, and 48 h after surgery. The mean areas under the curve (AUC) of LPR, LGR, and glycerol concentration also were higher in the electrocautery group than in the ultrasonic dissection group (4,387 vs. 1,639, P=0.011; 59 vs. 21, P=0.008; 7,438 vs. 4,169, P=0.008, respectively).

CONCLUSION

Electrosurgery causes more ischemic peritoneal tissue damage than ultrasonic dissection.

Extensive retroperitoneal hematoma in blunt trauma

OBJECTIVE

To report our experience of managing extensive retroperitoneal hematoma (RH) in patients with blunt trauma and to determine any associated factors affecting causation and mortality.

METHODS

In this retrospective observational study, patients diagnosed with extensive RH following blunt trauma admitted to King Saud Medical Complex, Riyadh, Kingdom of Saudi Arabia between January 2004 and December 2009 were included. Patient data were explored for injury severity score (ISS), associated injuries, location of hematoma, amount of blood transfusions, coagulation profile, operative management, hospital stay, and mortality. The outcomes in surviving and non-surviving patients were compared.

RESULTS

Out of 290 patients presenting with RH, extensive RH was found in 46 patients (15.8%). The overall mortality was 32.6%. The pelvis was the most frequent location of RH in combination with lateral and central zones (65.2%). The lower extremity and pelvic fractures were the most common injury. Associated intra-peritoneal injuries were present in 39.1% patients. An exploratory laparotomy was performed in 58.7% patients (n=27). A high ISS (55.9 versus 35.5, p<0.0001), abnormal coagulation profile (odds ratio [OR] 7.8, 95% confidence interval [CI] 1.974-30.932, p=0.005, and associated chest injuries OR 5.94, 95% CI 1.528-23.19, p=0.014) were independent factors associated with mortality.

CONCLUSION

Multiple musculoskeletal injuries in addition to intra-abdominal injuries and abnormal coagulation are major factors associated with the presence of extensive RH. High ISS, abnormal coagulation, and associated chest injuries are independent factors associated with mortality.

[Peritoneal structural injury in laparoscopic versus open radical resection for colorectal cancer: a prospective controlled study]

OBJECTIVE

To assess the differences in peritoneal microstructure injury between laparoscopic and open radical resection for colorectal cancer.

METHODS

A total of 50 patients with colorectal cancer were consecutively assigned into laparoscopic group (LO, n=27) and conventional laparotomy group (CO, n=23). Prospectively comparative analyses of operative time, intraoperative blood loss, number of lymph node harvest, positive rate of lymph nodes, length of specimen and resection margin involvement were performed. Optical microscope and scanning electron microscope were used to detect postoperative peritoneal injury between patients who received laparoscopic surgery or open surgery.

RESULTS

Compared with the CO group, operative time [(150.6+/-39.5) min vs (183.0+/-39.2) min, P<0.05] and intraoperative blood loss [(80.0+/-75.2) ml vs (234.5+/-235.3) ml, P<0.01] were significantly less in the LO group. No significant differences were found between two groups in length specimen, number of lymph nodes harvest, positive rate of lymph nodes, and all resection margins were negative (P>0.05). Optical microscope indicated less serosal injury in the LO group as compared to the CO group with regard to serosal integrity, continuity of covering adipocyte and mesothelial cell, and the aggregation level of erythrocytes and inflammatory cells (P<0.01). Scanning electronic microscopy showed more severe injury to colorectal serosa, mesothelium and basement membrane in the CO group as compared to the LO group.

CONCLUSION

With equal degree of radical resection, laparoscopic technique for colorectal cancer causes less peritoneal structural injury as compared with open surgery.

Impact of hollow viscus injuries on outcome of abdominal gunshot wounds

Abdominal gunshot wounds (GSW) are a source of morbidity and mortality. Limited data are available on the effect of hollow viscus injuries (HVI) secondary to gunshot wounds. GSW sustained in the Louisville area from 2004 to 2007 were reviewed. Attention was given to the impact of HVI from abdominal GSW. Statistical significance was determined. One-hundred ten patients sustained GSW with peritoneal violation. Eighty-six had HVI. Eighteen died after laparotomy with 15 having an HVI. Patients undergoing damage control (DC) have a significant increase in mortality compared with those not requiring DC. Exsanguination was the major cause of mortality (67%). Mortality directly related to HVI was found in 11 per cent. Twenty patients underwent DC with 11 deaths. Isolated HVI did not show a significantly increased mortality compared with other injury patterns involving solid organ or major vascular structures. Various methods of repair showed no significant survival advantage. Recognition and repair of HVI in abdominal GSW is crucial to patient salvage. Definitive repair of HVI at the initial operation should be considered. Primary repair of HVI is preferred although no survival disadvantage is seen in other forms of repair in marginally stable patients. Definitive repair at the initial operation decreases complications.

Minimally invasive retrieval of a bullet from the L5-S1 neural foramina after transperitoneal gunshot wound

BACKGROUND CONTEXT

In victims of gunshot wounds with retained bullet fragments in the central nervous system, delayed neurological deficit may result from copper-induced neurotoxicity. The mainstay of therapy involves surgical exploration and retrieval of fragments.

PURPOSE

A patient who presented with delayed neurological deficit after a transperitoneal gunshot wound is presented.

STUDY DESIGN

Technical report.

METHODS

A 25-year-old male, who was the victim of a transperitoneal gunshot wound with a copper-jacketed bullet, presented several weeks after recovering from his abdominal injury. The patient presented with a worsening radiculopathy in the L5 distribution and progressive dorsiflexion weakness. Subsequent imaging demonstrated a bullet lodged lateral to the L5-S1 neural foramina.

RESULTS

A minimally invasive approach with the use of a tubular retractor was used to retrieve the retained bullet. The lateral location of the bullet, the proximity of the nerve root to the bullet, and the limited visualization of the operative field from a minimally invasive approach, placed the nerve root at increased risk. Intraoperative myelography and electrophysiological monitoring were used to locate the nerve root in relation to the bullet and guide the extraction of the bullet. Postoperatively, the patient had complete resolution of his preoperative symptoms.

CONCLUSIONS

In cases where proximity to neural structures and limited visualization of bony landmarks may increase the risk of injury when extracting a foreign body, intraoperative myelography and electrophysiological monitoring are valuable adjuncts to further elucidate the surgical anatomy for a minimally invasive approach.

Advances in Abdominal Trauma

Emergency practitioners routinely encounter patients who suffer from abdominal trauma, be it blunt or penetrating. These injuries are often confounded by altered mental status, distracting injuries, or lack of historical information, and may present challenges in management. However, in the last several years new approaches to the diagnosis and management of abdominal trauma, including bedside ultrasound, newer generation computed tomography scans, laparoscopy, and the ability for selected nonoperative management expedite identification of life threatening injury and offer new options in treatment.

"Awake" laparoscopy for the evaluation of equivocal penetrating abdominal wounds

BACKGROUND

Diagnostic laparoscopy is useful for the assessment of equivocal penetrating abdominal wounds, and has become the modality of choice for the evaluation of such wounds at our institution. We hypothesised that, in appropriate patients, diagnostic "awake" laparoscopy (AL) could be performed under local anaesthesia in the emergency department (ED), allowing for expedited discharge and potential cost savings.

METHODS

Selected haemodynamically stable patients with penetrating abdominal injury underwent AL. Suitability for AL was at the discretion of the attending surgeon. Identification of peritoneal penetration by AL led to exploratory laparotomy in the operating room. Patients with no evidence of peritoneal penetration were discharged from the ED (ALneg). These patients were matched to a cohort of 24 patients who underwent diagnostic laparoscopy in the OR which was negative for peritoneal penetration (DLneg). Length of stay and hospital charges were compared.

RESULTS

Over a 30-month period, 15 patients underwent AL without complication. No peritoneal penetration was found in 11 patients. The remaining four patients underwent exploratory laparotomy, of which two were positive for intra-abdominal injury. Mean time to discharge was 7h in the ALneg group versus 18 h in the DLneg group (p=0.0003). Cost savings on hospital charges averaged 2227 US dollars per patient in the ALneg group compared with the DLneg group.

CONCLUSIONS

AL may be safely performed in the ED, allowing for expedited patient discharge. Cost savings are achieved by the avoidance of charges inherent to diagnostic laparoscopy performed in the operating room.

[Minilaparoscopy in penetrating abdominal trauma emergency room procedure with local anesthesia]

BACKGROUND

There are a number of unnecessary laparotomies in penetrating trauma, with a non worthless percentage of complications. When the peritoneal injury is identified, surgical exploration of the abdomen should be evaluated.

OBJECTIVE

Evaluate the penetration of the peritoneum, using a diagnose method with direct vision.

SETTING

Hospital de Urgencias de Córdoba. Trauma Hospital.

DESIGN

To evidence peritoneum trespassing, laparoscopy was performed with local anaesthesia in patients with penetrating abdominal trauma without signs of abdominal injury in the imaging methods and doubts in the physical examination, in a prospective setting.

POPULATION

Patient with penetrating abdominal trauma, treated between May 2004 to January 2005, with doubtful diagnose of peritoneal violation.

METHOD

Under sedation and local anaesthesia, a 5 millimetres laparoscope with 90 degrees vision was placed at umbilicus. The anterior abdominal wall, flanks and diaphragm were exanimate, looking for the peritoneal wound or free fluid.

RESULTS

Laparotomy could be avoided in four patients. In the four remaining, laparoscopy or conventional surgery was performed. Two presented hollow viscera injury, one hemoperitoneo and the other, minimum liver damage. There were not complications in both groups. The average hospital stay of the first group was 13 hours.

CONCLUSIONS

In selected patients, the minilaparoscopy is useful in decreased the percentage of unnecessary laparotomies and general anaesthesia, and its complications.

Closure of fascial defect at trocar sites after laparoscopic surgery

As laparoscopic surgery evolves, a growing number of different abdominal operations can now be performed. This necessitates the use of multiple large trocars. Herniation through the fascial defect created by trocar entry in laparoscopic interventions has been reported at a rate of 1-6%. We describe a simple closure technique for fascial defects at trocar sites after laparoscopic surgery. To facilitate the closure of the fascial defects of > or = 10 mm trocar entry sites, the surgeon places the upper end of a dissecting forceps through the fascial defect and tilts it so that the abdominal of the peritoneum comes into contact with its flat surface. The assistant retracts the skin and subcutaneous tissue and the "J" needle with the appropriate suture material is then used to take a stitch through the fascia under direct vision. The sharp end of the needle is prevented from coming into contact with any deeper structure as it slides on the flat surface of the dissecting forceps. The stitch is then pulled up to lift the edge of the fascia and the needle is passed from the opposite edge of the fascia in the same manner and then the suture is ligated. The aforementioned technique is easy to perform and facilitates the closure of the fascial defect at trocar sites, and there is no extra cost for the procedure.

Effect of plasma fibronectin on the incisional wound healing in rats

BACKGROUND

Abdominal wall repair after celiotomy is important because insufficient incisional wound strength results in wound failures such as fascial dehiscence and herniation. Plasma fibronectin (pFn) has been shown to play an important role in wound healing. The purpose of this study was to investigate whether pFn improves incisional wound healing in a rat skin incision and celiotomy model.

METHODS

Rats underwent a linear skin incision in the dorsal plane or a full-thickness incisional wound (celiotomy) in the abdominal wall. The same operative procedures were performed on rats whose pFn levels were reduced by antirat pFn serum. The wounds were sutured, and purified human pFn or albumin was given intravenously.

RESULTS

After the celiotomy, pFn levels decreased immediately and reached a minimum at 3 h after incision. A single injection of pFn (10 mg/kg) significantly increased the breaking strength of the skin and the bursting pressure of the abdominal wall. The amount of hydroxyproline in the skin incisional wound with pFn was significantly greater than with an injection of albumin as control. In rats with pFn levels decreased by antirat pFn serum, a single administration of pFn significantly increased the breaking strength of the skin and the bursting pressure of the abdominal wall compared to a control injection of albumin.

CONCLUSIONS

It is important for wound healing to maintain sufficiently high levels of pFn. A single intravenous injection of pFn after celiotomy may be useful in the prevention of fascial dehiscence and herniation.

Impact of peritoneal tears on the outcome and late results (4 years) of endoscopic totally extra-peritoneal inguinal hernioplasty

BACKGROUND

The reported rate of intra-operative peritoneal laceration during endoscopic extra-peritoneal hernioplasty (TEP) ranges from 10 to 64%.

AIMS

To evaluate in a prospective study the predictive factors of peritoneal tears, their consequences in terms of outcome and late results.

PATIENTS AND METHODS

Between July 1994 and December 2000, we performed 467 endoscopic extra-peritoneal hernia repairs (TEP). In 14.8% of the cases, single or multiples recurrences after conventional open herniotomy were treated. One hundred and forty-nine patients (38%) had had previous surgery (appendectomy); 277 procedures (70.8%) were performed by experienced surgeons and 114 (29.2%) by surgical trainees. We used a diathermic hook in 26.3% of the procedures. The mean follow-up period was 68 months (48-100).

RESULTS

Peritoneal tears occurred in 43 patients (10.9%). Six of them (13%) required operative closure, and six a conversion (four Lichtenstein, one Shouldice, and one TAPP). In 37 cases (86%), the tears were not closed. Peritoneal tears were significantly correlated with surgical experience, Nyhus classification, scar adhesion from previous surgery and the use of sharp instruments. Peritoneal tears interfere significantly (P=0.001) with the operating time (82 vs. 63 min) and conversion rate (13.9 vs. 1.7%). It does not affect the outcome and late results in terms of recurrences, pain, or small bowel obstruction.

CONCLUSION

Our data suggest that peritoneal tears in the vast majority of cases may be safely managed without peritoneal closure. In case of peritoneal laceration, the operative time was significantly longer, and the conversion rate was increased. These situations do not affect the outcome and late complications compared with the procedures without peritoneal tears.

The role of the muscarinic system in regulating estradiol secretion varies during the estrous cycle: the hemiovariectomized rat model

There is evidence that one gonad has functional predominance. The present study analyzed the acute effects of unilateral ovariectomy (ULO) and blocking the cholinergic system, by injecting atropine sulfate (ATR), on estradiol (E2) serum concentrations during the estrous cycle. The results indicate that ULO effects on E2 concentrations are asymmetric, vary during the estrous cycle, and partially depend on the cholinergic innervation. Perforation of the left peritoneum resulted in lower E2 serum concentrations in the three stages of the estrous cycle. At proestrus, unilateral or bilateral perforation of the peritoneum resulted in lower E2 serum concentrations.ULO of the right ovary (left ovary in situ) resulted in significantly higher E2 concentrations than animals with ULO of the left ovary (right ovary in situ). ATR treatment to ULO rats on D1 resulted in a significant drop of E2 serum concentrations. ULO rats treated with ATR on D2 or P, resulted in an asymmetrical E2 secretion response; when the right ovary remained in situ an increase in E2 was observed, and a decrease when the left ovary remained in situ. The results obtained in the present study suggest that each ovary's ability to compensate the secretion of E2 from the missing ovary is different and varies during the estrous cycle. The results also suggest that the cholinergic system participates in regulating ovarian E2 secretion. Such participation varies according to the ovary remaining in situ and the stage of the estrous cycle of the animal. The results agree with previously stated hypothesis of a neural pathway arising from the peritoneum that participates in regulating E2 secretion, and also supports the idea of cross-talk between the ovaries, via a neural communication, that modulates E2 secretion.

Biventricular Repair of Ebstein's Anomaly With Pulmonary Atresia in a Low Birth Weight Neonate

Cyanotic neonates with Ebstein's anomaly associated with pulmonary atresia are a subgroup with the high mortality rate in pediatric cardiac surgery. We report a case of a severely symptomatic low birth weight neonate with Ebstein's anomaly and pulmonary atresia. A biventricular repair with Danielson-type tricuspid valve repair was performed. The baby tolerated the procedure with adequate hemodynamics, but died of peritoneal hemorrhage on the second postoperative day. This report could be an addition to the recent literature regarding the feasibility of biventricular repair for symptomatic neonates with Ebstein's anomaly even in low birth weight neonates.

Peritoneal injury by methylglyoxal in peritoneal dialysis

BACKGROUND

Peritonealdialysis (PD) is a common treatment for patients with reduced or absent renal function. Long-term PD leads to peritoneal injury with structural changes and functional decline, such as ultrafiltration loss. At worst, peritoneal injury leads to encapsulating peritoneal sclerosis, a serious complication of PD. Glucose degradation products contained in PD fluids contribute to the bioincompatibility of conventional PD fluids. Methylglyoxal (MGO) is an extremely toxic glucose degradation product. The present study examined the injurious effect of MGO on peritoneum in vivo.

METHODS

Male Sprague-Dawley rats (n = 6) were administered PD fluids (pH 5.0) containing 0, 0.66, 2, 6.6, or 20 mmol/L MGO every day for 21 days. On day 22, peritoneal function was estimated by the peritoneal equilibration test. Drained dialysate was analyzed for type IV collagen-7S, matrix metalloproteinase (MMP), and vascular endothelial growth factor (VEGF). Histological analysis was also performed.

RESULTS

In rats receiving PD fluids containing more than 0.66 mmol/L MGO, peritoneal function decreased significantly and levels of type IV collagen-7S and MMP-2 in drained dialysate increased significantly. In the 20-mmol/L MGO-treated rats, loss of body weight, expression of VEGF, thickening of the peritoneum, and formation of abdominal cocoon were induced. MMP-2 and VEGF were produced by infiltrating cells in the peritoneum. Type IV collagen was detected in basement membrane of microvessels.

CONCLUSION

MGO induced not only peritoneal injury but also abdominal cocoon formation in vivo. The decline of peritoneal function may result from reconstitution of microvessel basement membrane or neovascularization.

[Surgical management of post-operative peritonitis]

Post-operative peritonitis usually results from intra-operative or delayed injury to a digestive organ; it is accompanied by a high mortality rate. Prognosis is directly related to early diagnosis and appropriate re-intervention. Clinical and laboratory signs of gravity impose prompt re-operation. Imaging exams such as CT will aid in diagnosis and guide the therapeutic approach. Treatment specifically adapted to the etiologic cause must be thorough and complete from the start.

Death by attack from a wild boar

Attacks on humans by wild animals causing fatal injuries are not uncommon in rural and forest areas of India. But death occurring due to attack by a wild boar is rare. As the victims of boar attack are usually recovered from dense forest areas, the investigating officers could be misled as to the nature of infliction of these multiple, fatal penetrating injuries to a possible homicide. Unlike the injuries inflicted by wild cats, canines and bulls, the hallmark of boar attack is the infliction of multiple penetrating injuries to the lower part of the body. This case is reported for its rarity, for the awareness of the possible injuries in such unnatural deaths, and for the factors predisposing to a boar attack.

Emergency diagnostic paracentesis to determine intraperitoneal fluid identity discovered on bedside ultrasound of unstable patients

Patients presenting with hypotension may be evaluated with a FAST (Focused Abdominal Sonography for Trauma) examination as recent literature has suggested its utility in the unstable patient. Those who are found to have intraperitoneal fluid on the FAST examination may have solid organ injury from unknown trauma, ruptured abdominal aortic aneurysm (AAA), hemorrhaging ovarian cyst, ruptured ectopic pregnancy, or other disease process responsible for intra-periteal blood. However, because ultrasound does not assist in fluid identification, it is possible that the fluid present is not blood, but ascites. Further, a decision may need to be made regarding emergent surgical intervention or blood transfusion vs. aggressive fluid resuscitation or pressors followed by other testing such as computed tomography. This case series illustrates the utility of an ultrasound guided, emergent diagnostic paracentesis in the management of unstable patients found to have a positive FAST examination. Six unstable patients were evaluated with the FAST examination and found to have large quantities of intraperitoneal fluid. In each case the fluid was sampled and proposed management changed due to fluid identification.

The contribution of laparoscopy in evaluation of penetrating abdominal wounds

BACKGROUND

Penetrating abdominal wounds are traditionally explored by laparotomy. We investigated prospectively the role of laparoscopy within a defined protocol for management of penetrating abdominal wounds to determine its safety and advantages over traditional operative management.

STUDY DESIGN

The study inclusion criteria were: stab and gun shot abdominal wounds, including junction zone injuries; stable vital signs; and absence of contraindications for laparoscopy. Diagnostic end points included detection of peritoneum or diaphragm violation, visceral injuries, and other indications for laparotomy. Systematic examination was undertaken using a multiport technique whenever the peritoneum or diaphragm had been violated. All repairs were done by open operation.

RESULTS

A total of 40.6% of patients with penetrating trauma fulfilled study criteria (52 patients). Of these, 33% had no peritoneal penetration; 29% had no visceral injuries despite violation of peritoneum or diaphragm; 38% had visceral injuries, of which 40% (mainly liver and omentum) required no intervention. Twelve patients (23% of total) had open repairs. No missed injuries or death occurred in the study. Overall, 77% of penetrating injuries with stable vital signs avoided exploratory laparotomy. Compared with National Trauma Data Bank information for patients with the same Injury Severity Scores, hospitalization was reduced by more than 55% for the entire series.

CONCLUSIONS

Laparoscopy for penetrating abdominal injuries in a defined set of conditions was safe and accurate, effectively eliminating nontherapeutic laparotomy and shortening hospitalization.

Early results of a randomized multicenter trial comparing Prolene and VyproII mesh in bilateral endoscopic extraperitoneal hernioplasty (TEP)

BACKGROUND

The use of mesh in inguinal hernia surgery has become increasingly popular despite the potentially harmful effects that foreign material may exert on human tissue. The purpose of this study was to compare the use of a lightweight mesh vs a standard hernia mesh in bilateral endoscopic hernioplasty.

METHODS

This single-blinded multicenter trial, 140 men with bilateral inguinal hernias were randomized to undergo totally extraperitoneal endoscopic hernioplasty (TEP) with either Prolene or VyproII. The randomization and all data management were done via the Internet.

RESULTS

A total of 139 patients were operated on as allocated. The follow-up was complete in 94% of the patients. The median (range) operating times were 85 min (45-140) and 73 min (35-165) for the Prolene and VyproII groups, respectively. (p = 0.01). The difference was due to uneven distribution of the allocated patients to study groups among individual surgeons. The time to return to work was similar (11 vs 9 days, p = 0.08). The time to return to normal daily activities was 19 days (1-133) in the Prolene group and 12.5 days (0-237) in the VyproII group (p = 0.06). There were no significant differences between the groups in their scores on the Visual Analogue Scale or SF-36 Health Scores during the 8-week follow-up.

CONCLUSIONS

The use of Prolene and VyproII meshes in bilateral endoscopic repair of inguinal hernia seems to result in similar short-term outcome and quality of life. However, there was a tendency toward faster return to normal activity among VyproII patients.

The Role of Laparoscopy in Penetrating Abdominal Stab Wounds

The role of diagnostic laparoscopy (DL) in abdominal stab wounds (ASWs) is not clearly defined. We hypothesized that peritoneal penetration (PP) during DL was a valid indication to convert to an exploratory laparotomy (EL). Retrospective review of hemodynamically stable ASWs requiring operation. A total of 161 patients with ASWs were identified, with 36 of 92 patients (39.1%) undergoing DL converted to EL. All 36 patients had PP; 20 of 36 (55.6%) ELs were therapeutic (TL). The number of nontherapeutic laparotomies (NTLs) prevented was 56 (60.9%). Five of 92 patients had PP on DL but did not undergo EL. Twenty-four of 69 patients who underwent initial EL had an NTL (34.8%). If this group had undergone an initial DL, and PP was used to determine need for EL, the number of NTLs would have been reduced to 10 (14.5%), a 58.3% reduction. Evidence of PP during DL is a reasonable indicator to determine the need for EL and reduce the number of NTLs.

Transforming growth factor-beta: importance in long-term peritoneal membrane changes

We have provided evidence from adenovirus-mediated gene transfer to the peritoneum that transforming growth factor-beta1 mimics many of the functional and structural changes in the peritoneum in patients on long-term peritoneal dialysis, including fibrosis, increased submesothelial thickness, angiogenesis, increased solute transport, and ultrafiltration dysfunction. We review several key properties of this important fibrogenic molecule.