Live Donation of Corneal Tissue in the Setting of Orbital Exenteration for Malignancy

Background. The availability of corneal tissue is a major limiting factor in utilizing keratoplasty for correction of corneal blindness. Viable corneal tissue is typically difficult to obtain as posthumous donation is required to avoid significant morbidity and loss of vision in live patients. As a result, the possibility of obtaining viable corneal tissue from a living donor is rarely discussed. This report describes a case in which corneal donation was completed in a living patient undergoing exenteration for invasive squamous cell carcinoma of the maxillary sinus. Performing corneal donation in similar patients in the future should be considered by head and neck surgeons as an opportunity to increase the availability of corneal tissue.

Implementation of anesthesia quality indicators in Germany : A prospective, national, multicenter quality improvement study

BACKGROUND

In 2016 the German Society of Anesthesiology and Intensive Care Medicine (DGAI) and the Association of German Anesthetists (BDA) published 10 quality indicators (QI) to compare and improve the quality of anesthesia care in Germany. So far, there is no evidence for the feasibility of implementation of these QI in hospitals.

OBJECTIVE

This study tested the hypothesis that the implementation of the 10 QI is feasible in German hospitals.

MATERIAL AND METHODS

This prospective three-phase national multicenter quality improvement study was conducted in 15 German hospitals and 1 outpatient anesthesia center from March 2017 to February 2018. The trial consisted of an initial evaluation of pre-existing structures and processes by the heads of the participating anesthesia departments, followed by a 6-month implementation phase of the QI as well as a final re-evaluation phase. The implementation procedure was supported by web-based implementation aids ( www.qi-an.org ) and internal quality management programs. The primary endpoint was the difference in the number of implemented QI per center before and after implementation. Secondary endpoints were the number of newly implemented QI per center, the overall number of successful implementations of each QI, the identification of problems during the implementation as well as the kind of impediments preventing the QI implementation.

RESULTS

The average number of implemented QI increased from 5.8 to 6.8 (mean of the differences 1.1 ± 1.3; P < 0.01). Most frequently the QI perioperative morbidity and mortality report (5 centers) and the QI temperature management (4 centers) could be implemented. After the implementation phase, the QI incidence management and patient blood management were implemented in all 16 centers. Implementation of other quality indicators failed mainly due to a lack of time and lack of structural resources.

CONCLUSION

In this study the implementation of QI was proven to be mostly feasible in the participating German hospitals. Although several QI could be implemented with minor effort, more time, financial and structural resources would be required for some QI, such as the QI postoperative visit.

[Implementation of anesthesia quality indicators in Germany : A prospective, national, multicenter quality improvement study]

BACKGROUND

In 2016 the German Society of Anesthesiology and Intensive Care Medicine (DGAI) and the Association of German Anesthetists (BDA) published 10 quality indicators (QI) to compare and improve the quality of anesthesia care in Germany. So far, there is no evidence for the feasibility of implementation of these QI in hospitals.

OBJECTIVE

This study tested the hypothesis that the implementation of the 10 QI is feasible in German hospitals.

MATERIAL AND METHODS

This prospective three-phase national multicenter quality improvement study was conducted in 15 German hospitals and 1 outpatient anesthesia center from March 2017 to February 2018. The trial consisted of an initial evaluation of pre-existing structures and processes by the heads of the participating anesthesia departments, followed by a 6-month implementation phase of the QI as well as a final re-evaluation phase. The implementation procedure was supported by web-based implementation aids ( www.qi-an.org ) and internal quality management programs. The primary endpoint was the difference in the number of implemented QI per center before and after implementation. Secondary endpoints were the number of newly implemented QI per center, the overall number of successful implementations of each QI, the identification of problems during the implementation as well as the kind of impediments preventing the QI implementation.

RESULTS

The average number of implemented QI increased from 5.8 to 6.8 (mean of the differences 1.1 ± 1.3; P < 0.01). Most frequently the QI perioperative morbidity and mortality report (5 centers) and the QI temperature management (4 centers) could be implemented. After the implementation phase, the QI incidence management and patient blood management were implemented in all 16 centers. Implementation of other quality indicators failed mainly due to a lack of time and lack of structural resources.

CONCLUSION

In this study the implementation of QI was proven to be mostly feasible in the participating German hospitals. Although several QI could be implemented with minor effort, more time, financial and structural resources would be required for some QI, such as the QI postoperative visit.

Outcomes of Recipients With Pancreas Transplant Alone Who Develop End-Stage Renal Disease

Recipients of pancreas transplant alone (PTA) may be at increased risk for developing end-stage renal disease (ESRD). The survival experience of PTA recipients developing ESRD has not been described. Furthermore, the relative survival of these patients as compared to diabetics on chronic dialysis is unknown. We studied all adult PTA recipients from January 1, 1990 to September 1, 2008 using the Scientific Registry of Transplant Recipients. Each PTA recipient developing ESRD was matched to 10 diabetics on chronic dialysis from the United States Renal Data System. Cox proportional hazards models were fitted to determine the relation between ESRD and mortality among PTA recipients, and the relation between PTA and mortality among diabetics on chronic dialysis. There were 1597 PTA recipients in the study, of which 207 developed ESRD. Those with ESRD had a threefold increase in mortality versus those without (adjusted hazard ratio 3.28 [95% confidence interval: 2.27, 4.76]). There was no significant difference in the risk of death among PTA recipients with ESRD versus diabetics on dialysis. PTA recipients developing ESRD are three times more likely to die than PTA recipients without ESRD; however, the risk of death in these patients was similar to diabetics on chronic dialysis without PTA.

Portal venous versus systemic venous drainage of pancreas grafts: impact on long-term results

Portal venous (PV) and systemic venous (SV) drainage methods are used in pancreas transplantation. The impact of the reconstruction technique on long-term outcome remains unclear. We compared the efficacy and side effects of both methods in 192 recipients who received synchronous pancreas kidney transplants between November 1995 and November 2007. SV and PV drainage were used in 147 and 45 cases, respectively. Pancreas function was determined by hemoglobin A1c levels and annual oral glucose tolerance test. Serum creatinine assessed kidney function. Serum lipid (low-density lipoprotein, high-density lipoprotein and cholesterol) levels and body mass index were measured annually. Patient and graft survival were calculated by log-rank analysis. Pancreas survival for SV versus PV patients was similar after 5 years (81.8% vs. 75.5%) and 10 years (65.1% vs. 60%; p = NS). Similarly, no difference was detected between the groups regarding kidney survival after 5 years (92.9% vs. 84.4%) and 10 years (81.6% vs. 75.5%; p = NS). Patient survival did not differ at 5 years (94.3% vs. 88.8%) and 10 years (85.1% vs. 84.4%; p = NS). Pancreas and kidney function and the lipid profiles were similar in both groups. SV and PV drainage of pancreas grafts offer similar long-term graft survival and function and choice of method should remain the preference of the surgeon.

Renal safety of CT angiography and perfusion imaging in the emergency evaluation of acute stroke

BACKGROUND AND PURPOSE

Multimodal CT imaging with contrast-enhanced CT angiography (CTA) and CT perfusion (CTP) is increasingly being used to guide emergency management of acute stroke. However, little has been reported about the safety of intravenous contrast administration associated with these studies in the acute stroke population, including cases in which baseline creatinine values are unknown. We investigated the incidence of contrast-induced nephropathy (CIN), defined as a 25% or more increase in baseline creatinine levels within 72 hours of contrast administration and chronic kidney disease in patients receiving CTA+/-CTP at our regional stroke center.

MATERIALS AND METHODS

We analyzed 198 patients who underwent contrast CT studies for evaluation of acute ischemic or hemorrhagic stroke at our center (2003-2007). Through retrospective chart abstraction, we analyzed serial creatinine levels (baseline to day 3) and later values (>/=day 4) where available. The incidences of CIN and/or chronic kidney disease were documented. After power analysis, CIN and non-CIN groups were compared by using the unpaired t test, Wilcoxon rank sum test, or Fisher exact test.

RESULTS

None of the 198 patients developed chronic kidney disease or required dialysis. Of 175 patients with serial creatinine measurements between baseline and day 3, 5 (2.9%) developed CIN. The incidence of CIN was 2% in patients who were scanned before a baseline creatinine level was available.

CONCLUSION

The incidence of renal sequelae is relatively low in acute stroke patients undergoing emergent multimodal CT scanning. Prompt CTA/CTP imaging of acute stroke, if indicated, need not be delayed in those with no history of renal impairment.

The effectiveness of renal transplantation as a treatment for recurrent uremic cardiomyopathy

Congestive heart failure is more prevalent in patients with end-stage renal disease than in the general population. Although optimal treatment has yet to be defined, these patients are considered to be at high risk for renal transplantation. The present report of a 27-year-old man describes a full recovery from uremic cardiomyopathy following a renal transplant. Despite the patient developing recurrent cardiac dysfunction following graft failure, a second transplant was successful, which, again, resulted in complete resolution of the cardiomyopathy. Patients with recurrent uremic cardiomyopathy following failed kidney transplantation should be considered for a second kidney transplant.

Innovative single-armed suture technique for microsurgical vasoepididymostomy

OBJECTIVES

Vasoepididymostomy outcomes are heavily dependent on the surgeon's microsurgical experience and skill. To avoid back-walling the tubular lumen, the needles are generally placed inside-out through the vasal lumen using double-armed microsutures. These double-armed sutures for infertility microsurgery are very expensive and may be difficult to obtain. We describe a randomized trial that used a novel single-armed suture placement pattern for vasoepididymostomy.

METHODS

Male adult Wistar rats underwent vasectomy. Two weeks later, vasoepididymostomies were performed using either a single-armed longitudinal intussusception vasoepididymostomy (n = 6) or a standard double-armed longitudinal intussusception vasoepididymostomy (n = 6) technique. After 9 weeks, patency was assessed functionally by evaluating for motile sperm distal to the anastomosis. If no motile sperm were visible, the mechanical patency of the anastomoses was tested by the ability of methylene blue to pass through the surgical anastomosis.

RESULTS

The patency rate for the double-armed vasoepididymostomy group was 100% (6 of 6) compared with 83.3% (5 of 6) for the single-armed vasoepididymostomy group. This difference was not significant (P = 0.50). Sperm granulomas were found in three (50%) of six anastomoses in the double-armed group and five (83%) of six anastomoses in the single-armed vasoepididymostomy group (P = 0.27). The mean operative times for the double and single-armed longitudinal intussusception vasoepididymostomy techniques were similar (35 minutes versus 43 minutes; P = 0.39).

CONCLUSIONS

The results of our study have shown that the single-armed suture technique to perform vasoepididymostomy is almost as effective as the double-armed technique. Although we still prefer to use double-armed sutures, we believe that this is a practical and effective alternative when specialized double-armed microsurgical sutures are not available.

Renal artery thrombosis following secondary cytoreduction in a patient with ovarian cancer

BACKGROUND

In order to successfully perform aggressive cytoreductive surgery for patients with recurrent epithelial ovarian cancer, resection of retroperitoneal disease in close proximity to major vessels is often required.

CASE

We describe a case of a 44-year-old female patient with a history of Stage IV carcinoma of the ovary, who underwent a successful secondary debulking procedure. To remove the left para-aortic tumor implant she required complete mobilization of the left kidney, with skeletonization of the left renal artery and vein. Postoperatively, the patient developed left renal artery thrombosis necessitating a unilateral nephrectomy.

CONCLUSION

This is, to our knowledge, the first reported case of renal artery thrombosis following a debulking procedure. Gynecologic oncologists should be aware of this possibility and be familiar with the diagnosis and management of this condition.

An analysis of the natural history of Peyronie's disease

PURPOSE

Little information exists on the natural history of PD. We defined the course of PD in a group of men with this condition who received no treatment.

MATERIALS AND METHODS

The study population comprised patients with PD who presented within 6 months of disease onset, had no medical treatment and were followed until at least 12 months after disease onset. At baseline and followup penile abnormality was determined following intracavernous injection and by measurement at maximum penile rigidity.

RESULTS

A total of 246 patients met inclusion criteria. At presentation mean age +/- SD was 52 +/- 22 years and the duration of PD was 3.5 +/- 1.5 months. At baseline in men with documented curvature 72% had dorsal, 17% had ventral and 11% had lateral curvature. Mean curvature at baseline was 42 +/- 22 degrees. Mean stretched flaccid penile length was 12.2 cm. The mean duration of PD at the followup assessment was 18 +/- 7 months. At followup stretched flaccid length had decreased to 11.4 cm (p = 0.035). Of the patients 32% complained of some degree of erectile dysfunction at baseline. All patients who reported penile pain had improvement and 89% reported complete resolution at followup. Of men with curvature 12% had improved, 40% remained stable and 48% had worsened at followup. In those in whom curvature improved the mean change was 15 degrees, while in those in whom curvature worsened the mean change was 22 degrees.

CONCLUSIONS

To our knowledge this is the largest study to explore the natural history of PD. A minority of men experienced improvement in penile abnormality, while penile length decreased during the 1-year followup. This information will permit clinicians to provide patients with realistic expectations at presentation for the evaluation of PD.

Outcome and late failures compared in 4 techniques of microsurgical vasoepididymostomy in 153 consecutive men

PURPOSE

Vasoepididymostomy remains one of the most technically challenging procedures in all of microsurgery. The technique has evolved from an end-to-end, to an end-to-side technique, then to intussusception end-to-side methods. We recently reported the superiority of 2-suture longitudinal and 3-suture triangulation intussusception techniques in rats. In the present study we report our results in humans. We evaluated all vasoepididymostomies performed by 1 surgeon from January 1992 until the present for patency, pregnancy and for disappearance of sperm after initial return of sperm to the ejaculate.

MATERIALS AND METHODS

We recorded the results of 153 consecutive vasoepdidymostomies done by 1 surgeon (MG) from January 1992 until February 2004. Four techniques were used, namely end-to-end (EE), end-to-side (ES), 3-suture triangulation intussusception (TIVE) and 2-suture longitudinal intussusception (LIVE). Data collected included technique, months of followup, sperm density, motility and morphology (WHO 1992 criteria), pregnancy outcome and late failures. Late failures were defined as having return of sperm to the ejaculate after vasoepididymostomy and then becoming azoospermic on at least 2 subsequent semen analyses.

RESULTS

A total of 153 men underwent bilateral vasoepididymostomies. The most recent 17 were LIVE, preceeded by 38 TIVE, 32 ES and 66 EE. Mean followup for the groups were 17.2 (LIVE), 70.8 (TIVE), 116.7 (ES) and 140.2 (EE) months, respectively. Intact sperm were seen in the ejaculates of 12 men (80%) in the LIVE group, 16 in the TIVE group (84%), 20 in the ES group (74%) and 30 men in the EE group (73%). Motile sperm were found in the ejaculates of 10 of 15 (67%) in the LIVE group, 13 of 19 (68%) in the TIVE group, 10 of 27 (37%) in the ES group and 20 of 41 (49%) in the EE group (p =0.2). Mean times for return of sperm to the ejaculate were 2.9, 2.8, 2.8 and 3.5 months, respectively. Pregnancies were reported by 4 men in the LIVE group all before 12 months, 6 in the TIVE group and 3 were by 12 months, and 4 each by the ES and EE groups with 3 and 2 by 12 months (p =0.07). Thus far, there have been no late failures in the LIVE group, only 1 in the TIVE group (8%), 5 in the ES group (50%) and 6 in the EE group (30%) (p =0.04).

CONCLUSIONS

Although vasoepididymostomy remains a technically demanding microsurgical procedure, recent technical innovations of TIVE and LIVE offer better or comparable outcomes compared with EE and ES procedures with the use of fewer sutures, which simplifies the performance of the anastomosis. In addition, the late failure rate is lower with the use of the intussusception techniques (LIVE and TIVE) with only 1 late failure in 22 men with return of sperm to the ejaculate procedures (4%) compared with 11 of 30 (37%) in the nonintussusception groups (p =0.006).

Laparoscopic cholecystectomy after the learning curve: what should we expect?

BACKGROUND

The introduction of laparoscopic cholecystectomy (LC) in the late 1980s was accompanied an increase in common bile duct (CBD) injuries. This retrospective analysis of 2,005 cholecystectomies performed at a single institution investigates the factors that have contributed to a record of zero CBD injuries in 1,674 consecutive LC.

METHODS

The medical records of 1,285 consecutive patients operated on from 7 July 1996 to 6 June 2003 were obtained. We also examined the peer review records of an additional 720 LC performed between 1 January 1990 and 7 July 1996.

RESULTS

There were no CBD injuries among 1,674 consecutive LC patients spanning the period since 1990. Of the 954 patients who underwent LC since 1996, six had a cystic duct leak and five had a duct of Luschka leak. Intraoperative cholangiography (IOC) was performed in 20.2% of cases (n = 193/954). Seventy of 157 patients who underwent cholangiography alone demonstrated one or more stones in the CBD (44.6%). In 40 patients (58.0%), endoscopic retrograde cholangio pancreatography (ERCP) was uniformly successful in clearing intraoperatively identified stones. In36.2% of cases, the stones were removed via laparoscopic CBD exploration (CBDE) (n = 25). In 5.8% of positive cases, the stones were removed via open CBDE (n = 4). Among 761 patients who did not undergo IOC, seven patients (0.92%) returned to the hospital for retained stones. Three of these patients had elevated liver function tests (LFT) preoperatively (1.3%) and four had normal LFT (1.1%).

CONCLUSIONS

Injuries of the CBD can be avoided by performing an extensive dissection of the triangle of Calot and by developing a critical view of the operative field to ensure the patient's safety during LC. If all LFT are normal and IOC is not performed, the occurrence of clinically significant stones postoperatively is minimal; in this group, only four patients had retained stones. Thus, in the face of normal LFT, routine IOC is unnecessary for a low CBD injury rate, and a return to the hospital for retained bile duct stones is rarely required, regardless of the number of times ductal stones are found on routine cholangiography. This implies that the significance of the stones discovered at IOC is questionable in most cases, thereby providing an argument against routine cholangiography. Most discovered CBD stones can be treated by ERCP, thus obviating the need for the T-tube drainage associated with CBDE. The 21st century finds LC to be a mature and safe surgical procedure.

Laparoscopic cholecystectomy in cirrhotic patients

BACKGROUND

Due to unacceptable increases in intra- and postoperative complications and associated morbidity, cirrhosis of the liver is often considered to be a contraindication for laparoscopic cholecystectomy (LC). However, recent advances have now made it increasingly possible for experienced surgeons to perform LC on this high-risk population. The aim of this study was to evaluate the impact of the coagulopathy associated with cirrhosis on the performance and results of LC. We hypothesized that the factors leading to hemorrhage, rather than Child's classification, would drive operating time and resource utilization.

METHODS

Between 1 July 1996 and 30 June 2003, 1,285 cholecystectomies were performed. Thirty one of these patients had evidence of cirrhosis at the time of operation. The 31 patients were divided into high, (low platelets, prolonged International Normalized Ratio) (n = 18), intermediate, (abnormal liver function tests, normal clotting) (n = 5), and low, (normal platelets, normal clotting, and normal liver function tests) (n = 8) surgical risk categories for further analysis. Based on the Child-Turcotte-Pugh (CTP) classification of cirrhosis, there were three grade C and 28 grade A or grade B patients.

RESULTS

There were 24 LC, three of which were started laparoscopically and then converted to open, and four open cholecystectomies. Operating room time ranged from 79 to 450 min, with the extent of coagulopathy correlating with the length of time needed to achieve satisfactory hemostasis. Median length of stay postoperatively in the high-risk group was 2 days (range, 0-20). Nine of the cholecystectomies were performed on an outpatient basis. One patient received a liver transplantation 5 months post-LC. There were no operative deaths, bile duct injuries, or returns to the operating room for bleeding. Blood product usage correlated with preexisting coagulopathy.

CONCLUSIONS

Currently, the classification of cirrhotic patients is normally done using the CTP score. However, preoperative platelet levels and INR more accurately predict the difficulty of cholecystectomy than CTP score, because intraoperative hemorrhage is the primary concern in these patients. This study demonstrates that preoperative degree of coagulopathy, and not Child's class, should guide the surgeon's approach and expectations when LC is performed in a cirrhotic patient.

Managing varicoceles in children: results with microsurgical varicocelectomy

Authors from New York present their experience of elective varicocelectomy, using microsurgical techniques, in a large series of children. They found the procedure to be safe and effective, and gave a much lower complication rate than the published rate in open varicocelectomy. The results of urethroplasty in post-traumatic paediatric urethral strictures are presented by authors from Mansoura. They found the overall success of one-stage perineal anastomotic repair of such strictures to be excellent, with very little morbidity.

OBJECTIVE

To report our experience of microsurgical subinguinal varicocelectomy in boys aged < or = 18 years.

PATIENTS AND METHODS

Boys aged < or = 18 years treated with microsurgical varicocelectomy between 1996 and 2000 at one institution were retrospectively reviewed. Indications for surgery included ipsilateral testicular atrophy, large varicocele or pain. Microsurgery was assisted by an operating microscope (x10-25) allowing preservation of the lymphatics, and the testicular and cremasteric arteries. Patient age, varicocele grade, complications and follow-up interval were recorded.

RESULTS

In all there were 97 microsurgical subinguinal varicocelectomies (23 bilateral) in 74 boys (mean age 14.7 years). Left-sided varicoceles were significantly larger (mean grade 2.9) than right-sided (mean grade 1.4) varicoceles. The mean follow-up was 9.6 months. There were four complications: two hydroceles, of which one resolved spontaneously after 4 months; one patient had persistent orchialgia that resolved after 8 months; and one developed hypertrophic scarring at the inguinal incision site. There were no infections, haematomas or intraoperative injuries to the vas deferens or testicular arteries. All boys were discharged home on the day of surgery.

CONCLUSIONS

Microsurgical subinguinal varicocelectomy in boys is a safe, minimally invasive and effective means of treating varicoceles. Compared with published results of the retroperitoneal mass ligation technique, which has a 15% overall complication rate and a 7-9% hydrocele occurrence rate, the microsurgical subinguinal approach appears to offer less morbidity, with a 1% hydrocele rate. We consider that microsurgical subinguinal varicocelectomy offers the best results with lower morbidity than other techniques.

Robotic microsurgical vasovasostomy and vasoepididymostomy in rats

Robotic and robotic assisted procedures are rapidly increasing in popularity amongst practicing surgeons and urologists. Robotic techniques are now commonly used to perform radical prostatectomies for prostate cancer and pyeloplasties for uretero-pelvic junction obstruction. Other robotic procedures include robotic assisted coronary artery bypass and partial nephrectomies. We initially studied the da Vinci surgical robot in order to determine the feasibility of adapting the robot to microsurgical vasovasostomy and vasoepididymostomy. In this paper, we describe our experience in developing a set of practice exercises using the da Vinci robot to prepare for these microsurgical procedures. We also review the design and results of our studies of robotic microsurgical vasovasostomy and vasoepididymostomy in rats.Finally, we discuss the potential future roles of robotic microsurgery in urology and surgery.

TOWARD A SUTURELESS VASOVASOSTOMY: USE OF BIOMATERIALS AND SURGICAL SEALANTS IN A RODENT VASOVASOSTOMY MODEL

PURPOSE

With 500,000 to 800,000 vasectomies performed annually and a reversal rate of 3% to 8% vasectomy reversal has become a commonly performed procedure. Two-layer microsurgical vasovasostomy remains the gold standard for surgical reconstruction of the vas. However, this procedure is technically demanding and time-consuming. We determined the ability of biomaterials and surgical sealants to decrease the number of sutures used, enhance anastomosis watertightness and decrease operative time.

MATERIALS AND METHODS

Adult male Wistar rats underwent vasectomy 2 weeks prior to vasovasostomy. Standard 2-layer microsurgical repair was performed in control animals. Experimental groups underwent 3-suture mucosal approximation and then completion of the anastomosis with a biomaterial membrane and/or synthetic sealant. The rats were sacrificed 9 weeks after vasovasostomy. Anastomotic patency was assessed functionally by the presence of motile sperm in the vas distal to the testes and anastomosis, and mechanically by methylene blue vasogram. The presence and size of sperm granulomas were also recorded.

RESULTS

Microsurgical vasovasostomy required significantly less time when biomaterial (42.7 minutes) or sealant (40 minutes) was used compared to the standard sutured group (102.5 minutes, each p < 0.001). There was no difference in patency between the standard sutured and biomaterial groups (90% vs 92%). Patency was significantly lower in the sealant groups, that is 70% in the suture, biomaterial and sealant group, and 75% in the suture and sealant group. The biomaterial group had only 1 sperm granuloma in 12 procedures, which was significantly better than the 7 in the control group (p <0.001).

CONCLUSIONS

Using a biomaterial wrap during vasovasostomy resulted in significantly decreased operative time and fewer sperm granulomas than in the control group. Sealants were not effective. Biomaterial wrap may support vasovasostomy and by decreasing leakage improve the outcome.

Robotic microsurgical vasovasostomy and vasoepididymostomy: a prospective randomized study in a rat model

PURPOSE

Microsurgical vasovasostomy and vasoepididymostomy remain technically challenging procedures. Refinements in technique have continually improved patency and pregnancy rates for the 2 procedures in experienced hands. Advances in surgical robotics produced the Da Vinci robot (Intuitive Surgical, Inc., Sunnyvale, California) with motion reduction and no tremor, features that may improve outcomes in microsurgery. We report a randomized prospective study of vasoepididymostomy and vasovasostomy using the Da Vinci robot in rats.

MATERIALS AND METHODS

A total of 24 adult male Wistar rats underwent vasectomy through a midline abdominal incision. Two weeks later the animals were randomized to microsurgical multilayer vasovasostomy, longitudinal vasoepididymostomy or robotic vasovasostomy and vasoepididymostomy groups. Outcomes measured included surgical time, complications, patency and sperm granuloma formation at 9 weeks.

RESULTS

Animals were sacrificed 9 weeks after microsurgery. There were no significant differences in complications among the groups. Robotic vasovasostomy was significantly faster than the conventional microsurgical technique (68.5 vs 102.5 minutes, p = 0.002). The robotic and microsurgical vasoepididymostomy groups did not differ significantly in time. Patency rates were 100% for the robotic vasovasostomy and vasoepididymostomy groups, and 90% in the microsurgical vasovasostomy and vasoepididymostomy groups. These differences were not significant. Sperm granulomas were found in 70% of microsurgical vasovasostomy anastomoses and 27% of robotic vasovasostomy anastomoses (p = 0.001). No significant difference in the sperm granuloma rate was found between the robotic or microsurgical vasoepididymostomy groups (42% and 50%, respectively, p = 0.37).

CONCLUSIONS

To our knowledge we report the first randomized prospective study using the Da Vinci robot for microsurgery. We believe that the improved stability and motion reduction during microsurgical suturing with the robot helped achieve excellent patency rates for vasovasostomy and vasoepididymostomy. The robot may also allow experienced microsurgeons to perform microsurgical procedures in patients at remote locations where no experienced microsurgeons are available.

p16/p14(ARF) cell cycle regulatory pathways in primary neuroblastoma: p16 expression is associated with advanced stage disease

p16 regulates the G(1)-S cell cycle transition by inhibiting the cyclin D-cyclin-dependent kinase (CDK)4/CDK6-mediated phosphorylation of retinoblastoma protein (pRb). We examined the possible derangement of the p16-CDK/cyclin D-pRb pathway in 40 primary neuroblastomas including 18 samples in the unfavorable stages (C and D) and 22 in the favorable stages (A, B, and Ds) by PCR, reverse transcription-PCR, Western blot, and immunohistochemistry and correlated the results with clinical outcome. No samples harbored alterations of the p16 gene. Interestingly, the samples in the unfavorable stages exhibited expression of p16 mRNA and protein more frequently than those in the favorable stages [mRNA, 9 of 18 (50%) versus 2 of 22 (9%), P = 0.006; protein, 5 of 16 (31%) versus 0 of 18 (0%), P = 0.013]. Alterations of the downstream components of the pathway were infrequent. pRb was deregulated in the majority of samples investigated [27 of 33 (82%), 24 with hyperphosphorylated pRb and 3 with no pRb protein]. The phosphorylation status of pRb did not correlate with p16 protein expression, suggesting that the elevated p16 protein may not be functioning properly to regulate the pathway. Among patients of all stages, p16 expression was significantly associated with a lower overall survival. There was no overexpression of MDM2, and loss of p14(ARF) expression and p53 mutation were infrequent events. Taken together, these findings suggest that up-regulated p16 expression may represent a unique feature of aggressive neuroblastoma.

Radiofrequency power calibration for magnetic resonance imaging using signal phase as indicator

A novel radiofrequency (rf) power calibration method for the purpose of nuclear magnetic resonance excitations based on monitoring signal phase rather than signal amplitude is described theoretically and is demonstrated experimentally. This unique method enables the determination of rf power required for any desired tip angle in clinical magnetic resonance imaging procedures with an accuracy of 1-5%, essentially independent of motion, flow, slice variations, and/or T1 and T2 variations. The advantages of the new method are discussed and are compared with currently common, amplitude-based calibration techniques.

Fast spin-echo characteristics of visual stimulation-induced signal changes in the human brain

A fast spin-echo (FSE) technique used in a conventional MR imaging scanner has been successfully developed for obtaining functional MR images with high spatial resolution and multiple slices. Our preliminary visual stimulation studies using the FSE technique show that the nuclear MR signal increases by 2.6% during activation in the primary visual cortex. These results provide evidence that the diffusion of tissue water molecules plays a key role in determining functional MR signal amplitude. Because the FSE functional MR imaging signal is extremely sensitive to microvascular (brain capillaries) hemodynamics, the FSE technique can be a powerful tool for studying the neuronal activity of the human brain.

Transcription factor AP-1 activity is required for initiation of DNA synthesis and is lost during cellular aging

Activation of the AP-1 complex of transcription factors is one of the earliest nuclear responses to mitogenic stimuli. We demonstrate directly that AP-1 activity is required for human cells to proliferate in response to serum. We also find that activity of the AP-1 complex is selectively reduced in old human fibroblasts prior to their entering a fully senescent state. Levels of Fos protein induced through diverse signal transduction pathways, the amount of AP-1 DNA binding activity in vitro, and the activity of an AP-1-dependent reporter gene in vivo are substantially decreased as fibroblasts age. Moreover, the composition of the AP-1 complex changes, so that old cells produce predominantly Jun-Jun homodimers instead of Fos-Jun heterodimers. Changes in AP-1 activity may be due in part to changes in posttranslational modification of Fos protein that impair its ability to form active DNA-binding heterodimers with Jun. These data suggest that changes in AP-1 activity may contribute to the inability of senescent cells to proliferate in response to mitogens.

Development of a receptor on a foreign nerve fiber in a Pacinian corpuscle

When the sensory fiber of a Pacinian corpuscle (in cat mesentery) is transected (at the inferior mesenteric nerve) transduction fails within 30 hours: the nerve ending produces no generator potentials in response to mechanical stimulation. Electrically elicited nerve impulse conduction continues for at least another 18 hours. A transducer mechanism develops on a regenerating nerve fiber when this fiber enters the denervated corpuscle. Such transducer development takes place on myelinated fibers from the inferior mesenteric nerve, which normally supplies corpuscles, as well as on myelinated hypogastric nerve fibers, which normally do not go to corpuscles, including fibers larger than the original corpuscle afferents.

Action Spectrum for Developmental Photo-Induction of the Blue-Green Alga Nostoc muscorum

The dark-grown cyanophyte requires a brief exposure to light from the 650 mmicro region of the spectrum before it can complete its developmental cycle. Induction is reversed by exposure to green light. A blue protein, presumably allophycocyanin (absorption maximum, 650 mmicro) has been demonstrated in aqueous extracts of the cyanophycean cells.