Archive for category: Letters to the Editor

Sir,

I am writing this from a trainee viewpoint.

I was delighted to read the articles by Khan et al. [1] and Elsamra et al. [2]. Both articles highlight how much the role of the surgical trainee has changed in this day and age.

Surgery has always been about precision, control and patient safety. It was interesting to note, with a new generation of trainees, the requirement for immediate information is there. Knowledge is very literally at our fingertips. Making use of modern web-based tools, in the same way, much of surgical training has become standardised, with the arrival of the ISCP log book, and more recently, the robotic surgery curriculum, which was much welcomed. With these tools, we can easily self-audit our practice to see what our learning curve is. However, additional pressures are now put on surgeons with the advent of published surgical outcomes. In some ways, this is both a help and a hindrance to a trainee. It helps that you can easily monitor your learning curve and continuously readjust your technique and skills accordingly. It is a hindrance that training opportunities may be further restricted as a result. This is more so for open surgery, which may result in less training.  

Surgery is a speciality built on apprenticeship. However, in the modern world, the wealth of information available to trainees is vast. Trainees can learn via social media and link to conferences around the world. This emphasises why live cases are central to training. In a busy hospital, there may not often be time for a trainee to be taken through a procedure step-by-step. With live surgery supplementing training, the trainee already knows what to expect. In this age, we are very lucky. Not only can we read the theory behind the operation, but we can then view the procedure on the web and complete simulation training to improve our surgical skills, prior to approaching any patient in hospital. As a result, we can perfect our skills, even before performing the first operation.

Despite all the above, what still remains central and vital to surgery, is the master–apprentice relationship. With all the texts in the world, and all available resources, nothing can teach you quite so much as the voice of experience. To finish off, I know a lot of comments have been made about the BJUI being a journal that nurtures the younger generation, and a number of negative comments made as a result. As one of the younger generation I would like to say, it is nice to have a journal that listens and continues to support surgical training and education.

Sanchia S. Goonewardene* and Raj Persad**
*University of Warwick, **Southmead Hospital Bristol

References

1. Khan N, Abboudi H, Khan MS, et al. Measuring the surgical ‘learning curve’: Methods, variables and competency. BJU Int 2014; 113: 504–508
2. Elsamra SE,  Fakhoury M,  Motato H,  et al. The surgical spectacle: a survey of urologists viewing live case demonstrations. BJU Int 2014; 113: 674–678

 

Sir,

We read with great interest the paper by Oh et al. [1] and the paper by Pater et al. [2]. Their study confirmed the previously reported inverse relationship between prostate-specific antigen (PSA) value and body mass index (BMI). Indeed, they indicated a decrease in PSA for an increasing BMI with a 0.026 decrease in PSA for every unit increase in BMI. To date, the detection of prostate cancer (PCa) has become more common since the introduction of PSA, but overall mortality remains high with an estimated 27,360 deaths in 2009, and relative survival of patients diagnosed with prostate cancer has changed little.

One possible reason that screening for PCa using PSA has not achieved reduced mortality is that PSA can be confounded by weight. In fact, several previous studies have demonstrated an inverse association between PSA and BMI. Kim et al. demonstrated that PSA shows a significant linear trend only in the group with a BMI ≥ 25 kg/m with prostate examination [3].

Pater et al. investigated 767 patients, with mean BMI 28.7 kg/m²; where 78% were overweight or obese (BMI ≥25). Mean PSA was 1.28 ng/ml. Notably, 44 patients had at least 1 PSA level over 4.0 ng/ml [2]. There was a small, but statistically significant trend toward decreasing PSA for an increasing BMI.

However, multiple findings showed that obese men had lower serum PSA concentrations than normal weight men. PSA mass tended to be lower in obese patients, but is unlikely to be a consequence of lower serum testosterone concentrations. Oh et al. declared that the accuracy of PSA in predicting PCa did not change regardless of BMI category in Asian men [1]. Recently it was shown that initial PSA levels of 3471 patients were <30 ng/ml, undergoing multicore (≥12) transrectal ultrasound-guided prostate biopsy. The median PSA level in each BMI category was 7.84, 7.75, 7.33 and 5.79 ng/ml with BMI of <23, 23-24.9, 25-29.9, and ≥30 kg/m² respectively [1]. Therefore, it may be suggested that the PSA threshold should be lower in obese men to discriminate between PCa and benign conditions in the real clinical situation. Similarly, Yang et al. recruited 20,509 native Korean men and found a statistically significant trend towards a lower likelihood of having a serum PSA level ≥2.5 ng/ml with an increased BMI [4]. These results might affect PCa screening using serum total PSA. Indeed, the relationship between obesity and PSA is confounded by a number of factors, which likely explain the observed inverse association previously reported. These data showed that obesity can help clinical staff to interpret the value of PSA in screening for PCa. Meanwhile, Li et al. demonstrated the inverse relationship between PSA concentration and BMI, and hold that this might be explained by a hemodilution effect among obese men. A value between 3.32 and 3.68 ng/ml might be recommended for PSA screening in middle-aged obese Asian men [5].

Of note, a recent study showed that the result accuracy of PSA as a predictor of PCa in 917 Italian men, performing trans-rectal ultrasound-guided prostate needle biopsy, is not significantly altered by BMI. Bañez et al. highlighted that obesity does not negatively impact the overall ability of PSA to discriminate between PCa and benign conditions [6].

In summary, available evidence has demonstrated an inverse relationship between PSA and BMI. However, much of the data regarding the role of PSA in obese patients with PCa has been obtained from distinct populations and proves controversial. Therefore, further clinical studies may be required to explore comprehensively the accurate diagnosis of prostate cancer in obese men in the real clinical situation.

Chang-ming Lin^1,2, Chao-zhao Liang¹*

¹Department of Urology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230032, China, ²Department of Urology, The Central Hospital of Maanshan The Affiliated Hospital of Wannan Medical College,Maanshan, Anhui 243011, China

^*Correspondence: Chao-zhao Liang, e-mail: [email protected]

References

1. Oh JJ, Jeong SJ, Lee BK et al. Does obesity affect the accuracy of prostate-specific antigen (PSA) for predicting prostate cancer among men undergoing prostate biopsy. BJU Int 2013; 112: E265–E271
2. Pater LE, Hart KW, Blonigen BJ, Lindsell CJ, Barrett WL. Relationship between prostate-specific antigen, age, and body mass index in a prostate cancer screening population. Am J Clin Oncol 2012; 35: 490–492
3. Kim JH, Doo SW, Yang WJ, Song YS, Kwon SS. Prostate-specific antigen density: a better index of obesity-related PSA decrease in ostensibly healthy Korean men with a PSA <3.0 ng/mL. Urology 2013; 81: 849–852
4. Yang WJ. The likelihood of having a serum PSA level of >/=2.5 or >/=4.0 ng ml^-1 according to obesity in a screened Korean population. Asian J Androl 2013; 15: 770–772
5. Li F, Shen Z, Lu Y, Yun J, Fan Y. Serum prostate-specific antigen concentration and hemodilution among Chinese middle-aged obese men: a hematocrit-based equation for plasma volume estimation is induced. Cancer Epidemiol Biomarkers Prev 2012; 21: 1731–1734
6. Bañez LL, Albisinni S, Freedland SJ, Tubaro A, De Nunzio C. The impact of obesity on the predictive accuracy of PSA in men undergoing prostate biopsy. World J Urol 2012; doi: 10.1007/s00345-012-0919-9

From simulation to reality: the path forward for the trainee robotic surgeon

Sir,

As a trainee, I was delighted to see the articles from Hung et al. [1] and Murphy et al. [2] in the BJUI. They both raised points which trainees encounter in today’s practice. With advances in urology, there are many obstacles facing trainees, most notably robotics. Few advancements related to robotic training methods have been made. Current training courses may be followed by clinical implementation or fellowships [3]. In comparison, validated simulation-based training methods are now standard for laparoscopic surgery. In view of this, there are three issues which need to be addressed directly. The first is of a training programme for robotics, the second is addressing open surgery training in this cohort, and lastly, the position of simulation training in surgery.

A robotic surgery training programme – is it required?

Whilst UK trainees are used to using the Intercollegiate Surgical Curriculum Programme as a tool to further their training up to completion, this has not been extended to training in robotic surgery. At present, no such standard curriculum exists for robotic surgery. However, there are a number of programmes that highlight what a curriculum should cover.

The Yale University laparoscopic camera navigation curriculum is a proficiency-based program. This curriculum covers camera navigation, coordination and target visualization skills. Assessment includes time taken to complete a task, number of targets missed, drift (measure of the angle from the horizontal axis), total path length (measure of excess instrument motion), and the number of times the camera was in contact with tissue [4].

The University of Texas examined efficient and effective skill acquisition, but also the establishment of “standards” in terms of defining proficiency [5]. Inanimate exercises were used with designated skills. For example, peg transfer included hand-eye coordination, instrument to instrument transfer, wrist articulation, depth perception, and atraumatic handling. The curriculum includes an online tutorial, didactics with mandatory completion of multiple-choice questions, interactive sessions designed to teach console robotic instrumentation, and self-practice to proficiency. They concluded that although simulation has been widely accepted in surgical training, a validated curriculum is still needed for robotic surgery.

Cancer-control and quality-of-life outcomes achieved with radical prostatectomy are highly dependent on the surgeon’s technique and skill [6]. As such, appropriate selections of cases are required by educators. This was further examined by Davis et al. [6] and the importance of case difficulty was highlighted with prostate size, median lobe, obesity, previous abdominal surgery, hormonal use, and nerve-sparing strategy noted with the grading of trainees’ performance. The subjective grading and feedback was considered essential for a validated curriculum.

Over 30 reports have been published describing robotic surgical training outside of the operating room. A big part of this is simulation exercises designed to teach robotic skills, with promising results. Surgical training has traditionally been one of apprenticeships, with trainees observing and assisting their seniors, to one day hopefully become like them. However, surgical training has decreased in length due to the European Working Time Directive (EWTD) and the Modernizing Medical Careers (MMC) initiative.

Role of simulation training in surgery

With the da Vinci system, the surgeon sits separately at a console and the first assistant is at the table side. As a result, communication is a big part of robotics training. The first important step in operative surgery is overall perceptual awareness, cognitive understanding and visualisation of operation [7]. The second step is guided learning, with segmental operative steps performed under supervision, with constant and immediate feedback as an essential component. The final stage involves refinement of skills with precision and efficiency [7].

Lessons can be learned from laparoscopic training. Techniques used include operating on human cadavers and live animals to provide alternate methods of learning. Skills used range from basic skills to performing whole procedures. This highlights how simulation training must have good visual and tactile feedback.

Studies have been conducted demonstrating the eventual role of simulation in robotic surgical training [8]. Basic robotic skills can be learned relatively quickly using the da Vinci skills simulator, with a study demonstrating  greater than 10 repetitions is required to reach expert level [9]. It has also been observed apprentices achieve simulator proficiency after relatively short training durations [10] with a steep learning curve. Use of simulators may make the transfer of skills safer and more effective [11], but it does not cover all parameters of the operation itself. In addition, prior studies where a curriculum was used, demonstrated better outcomes than trainees not using one [11]. Whilst simulation is an important part of the initial step in learning an operation, it does not familiarise one with the mechanics of the robotic surgical system. Effective transfer of skills from simulators to real settings requires a structured curriculum [11].

Open surgery for the robotic surgeon – to learn or not to learn?

As Murphy et al. highlight, all training adds value. There is no such thing as wasted knowledge. Whilst focusing on robotic training is important, it is just as important for trainees to be able to perform the procedure as open surgery. There will be a case which must be converted to open and, as such, robotic trainees must be equally competent at open surgery. A robotics curriculum must take this into account and include management of complications as part of training.

A standardised new curriculum – the way forward

A curriculum that assesses both academic and manual dexterity components, in conjunction with each other, is required. The goal of any surgical curriculum should be to assess, train, re-assess and further train students. The required curriculum should be formed on a basis of skills identified through task analysis of actual robotic procedures, with simulator training initially.  

Primary steps would include positioning of patient and port insertion, before moving on to assisting with procedures, and eventually to the console and performing the operation in steps, then in whole. For example, a radical prostatectomy can be broken down into bladder take down, opening the endopelvic fascia, ligating the dorsal venous complex, dissection of anterior and posterior bladder neck, ligation and dissection of vas and seminal vesicles, pedicles, conducting a nerve sparing procedure if required, before urethral anastomosis and lymph node dissection.

Davis et al. grouped the 11 steps of the operation into “skill sets”: basic tissue dissection, advanced tissue dissection, bladder neck and sewing [6]. The authors also highlighted the role of sequential training, with an improvement in outcomes. At the same time, appropriate case selection for trainees is vital for the surgical educator. This paper highlighted at least 40 cases would be needed to get to grips with the procedures, more to refine technique [6].   

In conclusion, a new standardised curriculum needs to be developed, whether as an extension of ISCP or otherwise. Simulator training should be used initially for at least 15 cases, to re-enforce the procedure and skills associated, before moving on to patient cases. When starting robotics on patients, at least 40 cases are needed to gain the basic skills required, with greater numbers required for skills and precision.

Goonewardene SS, Persad R*
Homerton University Hospital, London, *Bristol Urological Institute, Southmead 

References

1. Hung AJ, Jayaratna IS, Teruya K, Desai MM, Gill IS, Goh AC. Comparative assessment of three standardized robotic surgery training methods. BJU Int 2013; 112: 864–71
2. Murphy DG, Sundaram CP. Comparative assessment of three standardized robotic surgery training methods. BJU Int 2013; 112: 713–14
3. Society of American Gastrointestinal and Endoscopic Surgeons. Fundamentals of Laparoscopic Surgery. Available at: https://www.flsprogram.org/. Accessed April 16, 2011
4. Shetty S, Panait L, Baranoski J et al. Construct and face validity of a virtual reality-based camera navigation curriculum. J Surg Res 2012; 177: 191–95
5. Dulan G, Rege RV, Hogg DC, Gilberg-Fisher KK, Tesfay ST, Scott DJ. Content and face validity of a comprehensive robotic skills training program for general surgery, urology, and gynecology. Am J Surg 2012; 203: 535–39
6. Davis JW, Kamat A, Munsell M, Pettaway C, Pisters L, Matin S. Initial experience of teaching robot-assisted radical prostatectomy to surgeons-in-training: can training be evaluated and standardized? BJU Int 2010; 105: 1148–54
7. Sachdeva AK. Acquiring skills in new procedures and technology: the challenge and the opportunity. Arch Surg 2005; 140: 387–89
8. Kelly DC, Margules AC, Kundavaram CR et al. Face, content, and construct validation of the da Vinci Skills Simulator. Urology 2012; 79: 1068–72
9. Brinkman WM, Luursema JM, Kengen B, Schout BM, Witjes JA, Bekkers RL. da Vinci skills simulator for assessing learning curve and criterion-based training of robotic basic skills. Urology 2013; 81: 562–6
10. Stefanidis D, Scerbo MW, Sechrist C, Mostafavi A, Heniford BT. Do novices display automaticity during simulator training? Am J Surg 2008; 195: 210–13
11. Abboudi H, Khan MS, Aboumarzouk O, et al. Current status of validation for robotic surgery simulators – a systematic review. BJU Int 2013; 111: 194–205

Sir,

In the Mangera et al. [1] study various natural and synthetic scaffold materials, potentially applicable for tissue engineering purposes, were carefully compared. Primarily these materials were investigated for their suitability, when seeded with cultured oral fibroblasts, as an in vivo tissue-engineering approach to treat, by restoring the pelvic floor tissue structure, women with pelvic organ prolapse or those with stress urinary incontinence (SUI). Two potential candidate biodegradable scaffold materials were identified to treat these women’s pathological conditions, synthetic poly(L) lactic acid (PLA) and natural small intestinal submucosa (SIS), as they supported good cell attachment and proliferation, and had biomechanical features of the native pelvic floor.

The effectiveness of PLA and SIS as scaffold materials in other tissue engineering areas has been documented since the 1990s, e.g. to obtain a tissue-engineered bladder [2,3]. Recent advances in the preparation of synthetic polymeric scaffolds have shown that electrospun polyethylene terephthalate and polyurethane, given their fibrous microarchitecture similar to extracellular matrix (ECM), can favourably support cell adhesion/growth without the need of co-acting them with ECM-derived proteins [4,5].

Among the complex problems, from bench-to-bedside, concerning the biomechanical and dynamic requirements of a tissue-engineered structure to treat SUI, the main one is its potential for a quick and durable response to the neuronal mechanisms involved in the urinary continence guarding reflex towards sudden increases in intra-abdominal pressure. Indeed, the pontine storage centre-dependent spinal glutamatergic signalling induces the activation of sacral Onuf’s nucleus pudendal motoneurones, that, in turn, promote the acetylcholine-supported stimulation of pelvic floor striated muscle/urethral rhabdosphincter nicotinic receptors, thus efficaciously supporting the ‘guarding reflex’ [6–8].

Presumably the Authors [1], in the course of experimentation, have taken into consideration the response of their tissue-engineered structure to such guarding reflex-related neuromuscular mechanisms; however, this was not discussed in their article.

Contardo Alberti
Surgical Semeiotics, University of Parma, Parma, Italy

References

1. Mangera A, Bullock AJ, Roman S, Chapple CR, MacNeil S. Comparison of candidate scaffolds for tissue engineering for stress urinary incontinence and pelvic organ prolapse repair. BJU Int 2013; 112: 674–85
2. Atala A, Vacanti JP, Peters CA, Madnell J, Retik AB, Freeman MR. Formation of urothelial structures in vivo from dissociated cells attached to biodegradable polymer scaffold in vitro. J Urol 1992; 148: 658–62
3. Oberpenning FO, Meng J, Yoo J, Atala A. De novo reconstruction of a functional urinary bladder by tissue-engineering. Nat Biotechnol 1999; 17: 149-155
4. Del Gaudio C, Baiguera S, Ajalloueian F, Bianco A, Macchiarini P. Are synthetic scaffolds suitable for the development of clinical tissue-engineered tubular organs? J Biomed Mater Res A 2013 [Epub ahead of print]. DOI: 10.1002/jbm.a.34883.
5. Alberti C. Tissue engineering as innovative chance for organ replacement in radical tumor surgery. Eur Rev Med Pharmacol Sci 2013; 17: 624–31
6. Blok BF, Holstege G. The central control of micturition and continence: implications for urology. BJU Int 1999; 83 (Suppl. 2): 1–6
7. Kitta T, Miyazato M, Chancellor MB, de Groat W, Nonomura K, Yoshimura N. α₂-adrenoceptor blockade potentiates the effect of duloxetine on sneeze induced urethral continence reflex in rats. J Urol 2010; 184: 762–8
8. Alberti C. Coadministration of low-dose serotonin/noradrenaline reuptake inhibitor (SNRI) duloxetine with α 2-adrenoceptor blockers to treat both female and male mild-to-moderate stress urinary incontinence (SUI). G Chir 2013; 34:189–94.