Benign prostatic hyperplasia (BPH) is one of the most common urological conditions affecting ageing men and represents a significant cause of lower urinary tract symptoms (LUTS). Progressive enlargement of the prostate gland may result in bladder outlet obstruction, leading to both storage and voiding symptoms that adversely affect quality of life. Although medical therapy plays an important role in early disease, surgical intervention is often required in patients with moderate to severe symptoms or complications of BPH.

Transurethral resection of the prostate (TURP) has long been considered the gold standard surgical treatment for BPH. It is a safe and effective procedure that provides durable relief of symptoms and improvement in urinary flow parameters. Traditionally, the success of TURP has been evaluated using subjective symptom scores such as the International Prostate Symptom Score (IPSS) and objective measures including maximum urinary flow rate (Qmax) and average flow rate (Qavg).

Despite widespread use, the relationship between prostate size, amount of tissue resected, and postoperative clinical outcomes remains controversial. Several studies have reported poor correlation between preoperative prostate volume and symptom severity, as well as between the absolute amount of tissue resected and postoperative improvement. This has led to interest in alternative parameters that may better reflect the adequacy of resection.

Residual prostatic weight ratio (RPWR), defined as the ratio of residual prostate weight after TURP to the initial prostate weight, has been proposed as a novel variable to assess completeness of adenoma removal. A lower RPWR theoretically represents more complete resection and may correlate with improved postoperative outcomes. The present study was undertaken to evaluate the correlation between RPWR and clinical outcomes following TURP in patients with BPH.

This prospective study was conducted at a tertiary care centre over a period of one year, from August 2014 to July 2015. A total of 50 patients with symptomatic benign prostatic hyperplasia were enrolled after obtaining institutional ethics committee approval and informed consent.

 Patient Evaluation

All patients underwent detailed preoperative evaluation, including history taking and physical examination with digital rectal examination. Laboratory investigations included routine blood tests and prostate‑specific antigen (PSA) estimation. Patients presenting with obstructive lower urinary tract symptoms were further evaluated using uroflowmetry to record Qmax and Qavg.

Prostate size was assessed using transabdominal ultrasonography with the patient in the supine position. Prostate dimensions were measured in sagittal and transaxial planes, recording anteroposterior and transverse diameters. Prostate volume was calculated using the prolate ellipsoid formula (length × anteroposterior diameter × transverse diameter × 0.523). Prostate weight was considered equivalent to volume, assuming a specific gravity similar to water.

Symptom severity was assessed using the International Prostate Symptom Score (IPSS), including the quality of life (QoL) component.

 Surgical Procedure

All patients underwent standard monopolar TURP using a 26‑Fr Storz resectoscope. The resected prostatic tissue was collected and weighed using a sensitive top‑loading weighing balance. The weight of resected tissue was considered equivalent to volume.

Residual prostate weight was calculated by subtracting the resected tissue weight from the initial prostate weight. RPWR was calculated using the formula:

 RPWR = Residual prostate weight / Initial prostate weight

Follow‑Up and Outcome Measures

Patients were followed up for 6 months postoperatively. IPSS, Qmax, and Qavg were reassessed and compared with preoperative values.

 Statistical Analysis

Data were expressed as mean ± standard deviation. Pre‑ and postoperative parameters were compared using paired and independent t‑tests as appropriate. Correlation analysis between RPWR and clinical outcomes was performed using Pearson’s or Spearman’s correlation coefficient. A p value < 0.05 was considered statistically significant.

A total of 50 patients were included in the final analysis. The age of patients ranged from 52 to 89 years, with a mean age of 68.96 ± 8.7 years. Mean prostate weight was 66.06 ± 16.8 g, ranging from 30 to 110 g. The mean weight of resected prostatic tissue was 54.14 ± 14.7 g.

The RPWR ranged from 0.07 to 0.50, with a mean value of 0.17 ± 0.07. Patients were stratified into three groups based on prostate volume: 31–50 g (Group I, n = 10), 51–70 g (Group II, n = 25), and >70 g (Group III, n = 15).

Urinary Flow Parameters

Preoperative Qmax values were comparable across the three groups, with mean values of 11.1 ± 2.92 ml/s in Group I, 9.92 ± 2.56 ml/s in Group II, and 9.33 ± 2.35 ml/s in Group III. At 6 months postoperatively, Qmax improved significantly in all groups to 18.90 ± 2.30 ml/s, 18.92 ± 2.08 ml/s, and 18.06 ± 2.47 ml/s, respectively (p < 0.001).

Similarly, mean Qavg improved significantly from preoperative values of 5.60 ± 1.38 ml/s, 5.04 ± 1.32 ml/s, and 4.73 ± 1.29 ml/s to postoperative values of 11.70 ± 1.37 ml/s, 11.04 ± 1.32 ml/s, and 10.08 ± 1.44 ml/s in Groups I, II, and III, respectively (p < 0.001).

Symptom Score (IPSS)

Mean preoperative IPSS was 11.30 ± 3.02 in Group I, 12.68 ± 3.32 in Group II, and 14.06 ± 2.22 in Group III. At 6 months following TURP, IPSS improved significantly in all groups to 2.00 ± 1.40, 2.00 ± 0.88, and 2.33 ± 0.97, respectively (p < 0.001).

The mean overall improvement in IPSS score was 10.04 points, while mean improvement in Qmax and Qavg were 8.27 ml/s and 6.64 ml/s, respectively.

Correlation with RPWR

RPWR values differed significantly across prostate volume groups (p < 0.005). Lower RPWR values were associated with greater improvements in IPSS, Qmax, and Qavg. A negative correlation was observed between RPWR and postoperative clinical improvement, indicating that patients with smaller residual prostate fractions experienced better symptomatic and functional outcomes.

Table 1. Baseline Demographic and Prostate Characteristics

Table 2. Changes in Symptom Scores and Urinary Flow Parameters After TURP

Table 3. Prostate Volume–Based Stratification and RPWR Correlation

Table 4. Correlation Between RPWR and Postoperative Outcomes

The primary objective of TURP is adequate removal of adenomatous tissue to relieve bladder outlet obstruction. However, the optimal extent of resection required to achieve maximal clinical benefit remains unclear. In this study, RPWR was used as an indicator of completeness of resection and its relationship with postoperative outcomes was evaluated.

Our results demonstrate significant improvements in urinary flow rates and symptom scores at 6 months following TURP, consistent with existing literature. Importantly, a negative correlation was observed between RPWR and postoperative improvement in IPSS, Qmax, and Qavg, suggesting that more complete adenoma removal is associated with superior outcomes.

Although patients with larger prostates had higher absolute resected tissue weights, prostate volume alone did not reliably predict postoperative improvement. This supports previous observations that prostate size and symptom severity are poorly correlated. RPWR, by contrast, may better reflect the functional impact of surgery by accounting for residual obstruction.

Several limitations should be acknowledged. Prostate volume was measured using transabdominal rather than transrectal ultrasonography, which may affect accuracy. Residual prostate weight was calculated rather than directly measured. Additionally, follow‑up was limited to 6 months, whereas symptom resolution may continue for up to 12 months in a subset of patients.

The residual prostatic weight ratio appears to have a measurable influence on postoperative clinical outcomes following TURP for benign prostatic hyperplasia. Lower RPWR values are associated with greater improvement in urinary flow rates and symptom scores. Although correlations are modest and likely influenced by additional factors, RPWR may serve as a useful adjunctive parameter in evaluating surgical adequacy and predicting early postoperative outcomes.

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