New Techniques for Resecting Bladder Tumors

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New Techniques for Resecting Bladder Tumors

Alexey G. Martov,¹ Dmitry V. Ergakov,² Nikolay A. Baykov,³ & Zhamshid Okhunov⁴

¹ Department of Urology, Federal Medico‐biology Agency, Moscow, Russia

² Department of Urology, Municipal Hospital No. 57, FMBA State Institute of Continuous Medical Education, Moscow, Russia

³ Department of Urology, Municipal Hospital No. 57, Moscow, Russia

⁴ Department of Urology, University of California, Irvine, CA, USA

Introduction

Bladder cancer is the second most commonly diagnosed urological malignancy. The incidence and prevalence of bladder cancer in western as well as in developing countries continue to rise [1]. Although it is not the most frequent malignancy, bladder cancer’s high recurrence and progression rates, as well as its long disease‐specific survival rate, makes the treatment for bladder cancer far more costly than that for other cancers, such as rectum, lung, and prostate [1]. In addition, because of the high recurrence rates, follow‐up procedures such as cystoscopies with biopsies and intravesical chemotherapy also contribute to the high costs [1]. Thus the primary aim of surgical and nonsurgical treatment strategies are to optimize the outcomes and reduce the secondary interventions.

The majority of patients with bladder cancer are diagnosed with a nonmuscle‐invasive bladder cancer (NMIBC). Most of these are candidates for transurethral resection of bladder tumor (TURBT), with conventional monopolar transurethral resection of the bladder being the gold standard for this operation. Complete and radical tumor removal during TURBT is essential for initial diagnosis and follow‐up strategy planning [2].

There are diagnostic, surgical, and oncologic limitations to the contemporary technology and techniques used for conventional TURBT. The main diagnostic issue is the absence of the detrusor layer in the pathology after TURBT. Without the presence of the muscle layer, pathologists are often unable to correctly define pT stages of bladder cancer. The second most common diagnostic issue is thermal damage to the specimens, which can significantly affect pathological results. As a result of these drawbacks, low‐quality pathologies may require a second‐opinion pathologist consultation, and additional costly immunohistochemical investigations [3]. Surgical disadvantages of conventional TURBT include bladder perforation, obturator nerve stimulation, bleeding, and ureteral ostium injury during or after the surgery. Although the complication rate of monopolar TURBT is low, for high‐risk patients there could be surgical and safety issues.

The oncological outcomes for any cancer procedure are major limitations. Piecemeal resection of the lesion ignores the parameter of negative surgical margins, leaving behind positive margins and viable cancer cells with potential for recurrence and metastasis. This approach also allows tumor cells to migrate into the irrigation fluid, which facilitates their implantation and early recurrence. Another issue is the possibility that tumor cells may disseminate into paravesical fat in the case of perforation [3].

In order to improve conventional TURBT, a “non‐piecemeal‐resection” endoscopic technique was developed with the aim of optimizing treatment results. The technique consists of entire (en bloc) tumor endoscopic removal by means of a loop and hook‐shaped or J‐shaped electrode. Initially, this technique did not gain widespread popularity because of the technical limitations of endoscopes and monopolar generators. However, with recent improvements and developments in monopolar and bipolar electrosurgery, the introduction of vaportrodes, holmium laser devices, and water jet technology, the en bloc tumor removal technique has been revisited.

The purpose of this chapter is to provide an overview of the current state of the en bloc technique, the surgical technique and technology used, patient selection strategies, indications and contraindications for the en bloc procedure, the feasibility of immediate intravesical chemotherapy, and postoperative follow‐up and catheterization time.

Technique of en bloc bladder tumor removal (see Video 157.1)

The procedure is initiated with induction of general anesthesia and positioning the patient in dorsal lithotomy position.

Step 1

The bladder is thoroughly and systematically inspected by rigid or flexible cystoscope, using bladder mapping. If the technology is available, photodynamic diagnosis, narrow band imaging, or computer virtual chromoendoscopy will significantly enhance tumor size detection and facilitate the identification of satellite sessile tumors [4, 5].

Step 2

Once the tumor has been detected and evaluated, the bladder mucosa, submucosal layer, and muscle layer are dissected (all at the distance of 0.5–1 cm) around the tumor base, with monopolar (bipolar) loops, a hook‐shaped (J‐shaped “sand‐wedge,” Figure 157.1) electrode, or an end‐firing laser fiber. All visible bleeding blood vessels are simultaneously coagulated. The tumor is circumferentially resected together with the base and separated from the bladder wall. The separation technique is different. When “frontal energy” is used (hook or J‐shaped electrodes, end‐firing laser fibers) the separation movement are like axe cuts; when “circular energy” is applied (circle or bent loops, Figure 157.2), the movements are similar to those used when sawing a tree.

Image described by caption and surrounding text. — **Figure 157.1** Sand‐wedge electrode.

Next, electrocautery (laser energy) is used to burn and seal the blood vessels.

Water jet technology has an additional step. A flexible hole probe (hybrid knife) penetrates the mucosa around the tumor base into the level of the resection margin. Water is pumped through the probe under the tumor base to elevate the tumor, and then the tumor is carefully resected in one piece with the base by the same instrument (Figure 157.3).

Step 3

Following resection of the tumor, resected specimens are actively aspirated through the sheath. Alternatively, tumor pieces can be removed using different forceps (baskets, extractors, etc.) (Figure 157.4). When large tumors are presented, specimens can be divided into smaller sections by conventional resectoscope loop and then removed.

Image described by caption. — **Figure 157.4** Extractor and removed tumor.

Step 4

Once the tumor has been removed, the resected area is checked for bleeding, possible perforations, or residual tumors. Photodynamic diagnosis, narrow band imaging, or chromoendoscopy can be used to enhance intraoperative visualization of the resection margin and detect tiny satellite papillary tumors.

Step 5

The final step of endoscopic operation for bladder cancer is postoperative chemotherapy instillation. If there is no severe bleeding or perforations, chemotherapeutic drugs can be instilled via a catheter immediately after instrument removal from the bladder.

Energy sources that are used for en bloc resection are listed in Table 157.1.

Table 157.1 Instrumentation for en bloc transurethral bladder resection.

Energy source	Resection device	Pro	Cons
Monopolar	Angled or flat loop Hook electrode Sand‐wedge (J‐shaped) electrode	Easily switched to transurethral resection No additional costs Many urologists are familiar	Obturator reflex High perforation risk Transurethral resection syndrome Thermal pathology injury
Bipolar	Rectangular longitudinal loop Hook electrode Button (mushroom) electrode	Patients with pacemakers, metal prosthesis No transurethral resection syndrome Less thermal pathology damage	Urethral stricture?
Waterjet (hybrid)	Hybrid knife	No or diminished perforation risk Good quality of pathology	Need for additional instruments for biopsy Relatively new technique
Ho:YAG	Laser fiber	Bloodless technology No pathology injury No obturator reflex Diminished perforation risk	High cost Time‐consuming technique
Tm:YAG	Laser fiber	The same as Ho:YAG Faster than Ho:YAG	High cost No long‐term data

Discussion

Ukai et al. from Japan reported using a J‐shaped needle electrode to remove bladder tumors and Kawada et al. reported the use of en bloc resection for a 2.5 cm papillary tumor in 1997 [3, 6]. Three years later, in 2000, Ukai and authors published their own experience of en bloc resection, using a J‐shaped needle monopolar electrode to make a circumferential incision around the tumor that also included a 5 mm safety margin [3]. The first step of the procedure was to make a blunt dissection from the line of incision. After the tumor was detached, it was removed using either a syringe or, in the case of large pieces, a laparoscopic retrieval bag [7]. The technique of cold‐cup biopsies to insure complete tumor removal was also described by some authors [8–10].

The use of holmium:YAG (Ho:YAG) laser for transurethral en bloc resection of bladder cancer was first published by Saito, who concluded that it was a safe and useful technique for pathological evaluation [8]. Wolters et al. published a paper using a thulium laser for en bloc tumor resection. They were able to demonstrate detrusor muscle in all six cases, showing that it was possible to achieve exact staging at the time of primary transurethral operation [9]. Nagele et al. proved the feasibility of waterjet‐induced resection to safely remove bladder tumors [10] and Fritsche et al. presented the first prospective clinical trial of waterjet‐induced resection [11]. In addition to finding the application to be safe and applicable for en bloc dissection, they also reported feasibility in tumor sizes up to 7.5 cm. These authors [10, 11] first injected saline into the submucosal layer under the tumor base. After the tumor was elevated from the bladder wall, it was then safe to use en bloc resection. The results of numerous published data are shown in Table 157.2.

Table 157.2 Results of en bloc tumor resection.

Authors, year	No. of patients	Tumor size (mm)	Follow‐up (mo)	Recurrences (%)
Electrosurgery
Ukai, 2010 [12]	97	>20	3–84 (27)	37
Hurle, 2016 [13]	87	<30	24	15
Hybrid knife
Fritsche, 2011 [11]	17	4–75	4–14	23.5
Ho:YAG laser
Xishuang, 2010 [14]	64	5–36	24	31.7
Tm:YAG laser
Muto, 2014 [15]	55	20–40	8–25 (16)	14.5

The data in Table 157.2 clearly show that the ideal tumor size for en bloc removal ranges from 2 to 4 cm, and the recurrence rate varies between 15% and 37%. Although many papers have looked at the efficacy and safety of en bloc resection, only a few publications have relatively large samples. Kramer et al. is currently the largest study in this particular field, with 221 patients enrolled at six academic hospitals in this European multicenter study [16]. Using monopolar/bipolar current or holmium/thulium laser energy, the results of this study found that en bloc resection of bladder tumor is a safe and reliable procedure, and provides high‐quality resections for tumors >1 cm.